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Ahmed, Ozomata D. "Hybrid propulsion system for CubeSat applications." Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/812899/.
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The CubeSats platform has become a common basis for the development and flight of very small, low cost spacecraft-particularly amongst University groups. The smallest CubeSats are just 1 litre in volume-comprising a 10.
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Green, Michael W. "HAPSS, Hybrid Aircraft Propulsion System Synthesis." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/817.
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Hybrid Aircraft Propulsion System Synthesis (HAPSS) is a computer program that sizes and analyzes pure-series hybrid electric propulsion systems for aircraft. The development of this program began during a NASA SBIR contract, in conjunction with Empirical Systems Aerospace (ESAero), with the creation of a propulsion fan design tool. Since the completion of this contract in July 2010, the HAPSS program has been expanded to combine the many aspects of a hybrid propulsion system such as the propulsive fans, electric motors, generators, and controllers, and the internal combustion engines.
This thesis describes the benefits and drawbacks of aircraft hybrid propulsion systems to reveal the usefulness of a program of this nature. The methodology behind HAPSS, the creation of the program, its operation, and its many applications are also discussed in detail. Finally, this thesis includes a brief example in which HAPSS is used to analyze a hybrid propulsion system for a commercial transport aircraft. This example demonstrated the usefulness of the program and revealed interesting behavior and trends unique to hybrid propulsion.
To date, the HAPSS program has been utilized on several different contract projects in which an aircraft hybrid propulsion system was designed. In the summer of 2012, a government organization in conjunction with ESAero will begin funding a contract to continue the development of HAPSS by adding functionality and improving accuracy while making the tool available to other government agencies.
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Åkesson, Elsa, Maximilian Kempe, Oskar Nordlander, and Rosa Sandén. "Unmanned Aerial Vehicle Powered by Hybrid Propulsion System." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277115.
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I samband med den globala uppvärmningen ökar efterfrågan för rena och förnybara bränslen alltmer i dagens samhälle. Eftersom flygindustrin idag är ansvarig för samma mängd växthusgaser som all motortrafik i Sverige, skulle ett byte till en avgasfri energikälla för flygfarkoster vara ett stort framsteg. Därför har projektet genom modellering framtagit ett hybridsystem av ett batteri och en bränslecell och undersökt hur kombinationen av olika storlekar på dem presterar i en driftcykel. Då batterier har hög specifik effekt men är tunga, kompletteras de med fördel av bränsleceller, som är lättviktiga och bidrar med uthållig strömförsörjning. På så sätt blir hybriden optimal för flygfarkoster. Kandidatarbetet är en del av projektet Green Raven, ett tvärvetenskapligt samarbete mellan instutitionerna Tillämpad Elektrokemi, Mekatronik och Teknisk Mekanik på Kungliga Tekniska Högskolan. Driftcykelmodelleringen gjordes i Simulink, och flera antaganden gjordes beträffande effektprofilen, samt bränslecellens mätvärden och effekt. Tre olika energihushållningsscheman skapades, vilka bestämde bränslecellseffekten beroende på vätgasnivån och batteriets laddningstillstånd. Skillnaden på systemen var vilka intervall av laddningstillstånd hos batteriet som genererade olika effekt hos bränslecellen. Det bästa alternativet visade sig vara 0/100-systemet, eftersom det var det enda som inte orsakede någon degradering av bränslecellens kapacitet.<br>In today’s society, with several environmental challenges such as global warming, the demand for cleanand renewable fuels is ever increasing. Since the aviation industry in Sweden is responsible for the sameamount of greenhouse gas emissions as the motor traffic, a change to a non-polluting energy source forflying vehicles would be considerable progress. Therefore, this project has designed a hybrid system of abattery and a fuel cell and investigated how different combinations of battery and fuel cell sizes perform ina drive cycle, through computer modelling. As batteries possess a high specific power but are heavy, thefuel cells with high specific energy complement them with a sustained and lightweight power supply,which makes the hybrid perfect for aviation. The bachelor thesis is a part of Project Green Raven, aninterdisciplinary collaboration with the institutions of Applied Electrochemistry, Mechatronics andEngineering Mechanics at KTH Royal Institute of Techology. The drive cycle simulations were done inSimulink, and several assumptions regarding the power profile, fuel cell measurements and power weremade. Three different energy management strategies were set up, determining the fuel cell powerdepending on hydrogen availability and state of charge of the battery. The strategies were called 35/65,20/80 and 0/100, and the difference between them was at which state of charge intervals the fuel cellchanged its power output. The best strategy proved to be 0/100, since it was the only option which causedno degradation of the fuel cell whatsoever.
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Ren, Zhongling. "Optimization Methods for Hybrid Electric Vehicle Propulsion System." Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235932.
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Design of hybrid vehicles is a hot topic because of the strict restriction on the emissions of the vehicle. The optimal design of hybrid vehicles becomes necessary to reduce the cost or emissions of the vehicle. The propulsion system of a hybrid electric vehicle is inherently more complex than that of a conventional vehicle as an electric power supply branch is added. The design involves topology design, component design and control design, where all phases are interrelated. The idea to handle all the three design phases together is called system level design. Due to its complexity, it is not possible time wise to evaluate all possible design options. Optimization algorithms are therefore needed to speed up the process. The variable types that appear in each design phase are different and multiple algorithms are needed. In this thesis, different algorithms are studied for their robustness for both continuous variables and discrete variables, as well as benchmarked for the Volvo internal optimization platform afterwards. Standard test cases are used to validate the algorithms and several features are added to an algorithm to make it more generic and efficient. Based on theoretical and experimental studies, recommendations for the selection of algorithms are proposed based on different types of variables.Based on the optimization platform, several different optimization coordination architectures for system level design are introduced and simultaneous and nested coordination architectures are tested by one specific industrial case in the second part of the thesis. Both methods appeared to be promising according to the result of the test case and they managed to reduce the convergence time dramatically. The vehicle model used was not precise enough to prove which method is the superior one but a more precise model can be introduced in the future to facilitate such a conclusion.<br>Hybridfordon är ett aktuellt ämne, på grund av den strikta regleringen gällande fordonsutsläpp. Den optimala designen av hybridfordon är nödvändig för att reducera kostnaden eller utsläppen. Motorsystemet hos ett elektriskt hybridfordon blir mer komplicerat än det hos ett konventionellt fordon, eftersom man måste ta hänsyn till försörjningen av elektrisk energi. Designprocessen involverar design av topologi, design av komponenter samt design av kontrollsystem. Idéen om att sammanfoga alla tre designfaser kallas systemnivådesign. På grund av komplexiteten är det tidsmässigt inte möjligt att evaluera samtliga möjliga designval. Därför behövs optimeringsalgoritmer för att snabba på processen. Olika typer av variabler berörs i de olika designfaserna och därför behövs olika algoritmer. I avhandlingen undersöks olika algoritmers robusthet för kontinuerliga och diskreta variabler samt deras prestanda mot en intern optimeringsplattform. Standardiserade testfall används för att validera algoritmerna vartefter algoritmerna görs mer effektiva och generella. Baserat på teoretiska och experimentella studier föreslås rekommendationer för val av algoritmer baserat på olika typer av variabler. Baserat på optimeringsplattformen introduceras flera olika optimeringskoordinationsarkitekturer för systemnivådesign, och samtidiga och samordnade koordinationsarkitekturer testas för ett specifikt industrifall i den andra delen av avhandlingen. Båda metoderna tycktes vara lovande enligt resultatet av testfallet, och de lyckades sänka konvergensperioden dramatiskt. Den använda fordonsmodellen var inte tillräckligt exakt för att bevisa vilken metod som är den överlägsna, men en mer exakt modell kan introduceras i framtiden för att underlätta en sådan slutsats.
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Lundin, Johan. "Flywheel in an all-electric propulsion system." Licentiate thesis, Uppsala universitet, Elektricitetslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-222030.
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Energy storage is a crucial condition for both transportation purposes and for the use of electricity. Flywheels can be used as actual energy storage but also as power handling device. Their high power capacity compared to other means of storing electric energy makes them very convenient for smoothing power transients. These occur frequently in vehicles but also in the electric grid. In both these areas there is a lot to gain by reducing the power transients and irregularities. The research conducted at Uppsala university and described in this thesis is focused on an all-electric propulsion system based on an electric flywheel with double stator windings. The flywheel is inserted in between the main energy storage (assumed to be a battery) and the traction motor in an electric vehicle. This system has been evaluated by simulations in a Matlab model, comparing two otherwise identical drivelines, one with and one without a flywheel. The flywheel is shown to have several advantages for an all-electric propulsion system for a vehicle. The maximum power from the battery decreases more than ten times as the flywheel absorbs and supplies all the high power fluxes occuring at acceleration and braking. The battery delivers a low and almost constant power to the flywheel. The amount of batteries needed decreases whereas the battery lifetime and efficiency increases. Another benefit the flywheel configuration brings is a higher energy efficiency and hence less need for cooling. The model has also been used to evaluate the flywheel functionality for an electric grid application. The power from renewable intermittent energy sources such as wave, wind and current power can be smoothened by the flywheel, making these energy sources more efficient and thereby competitive with a remaining high power quality in the electric grid.
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Chaudhari, Anita. "Thermodynamic analysis, modelling and control of a novel hybrid propulsion system." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/9878.
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Stringent emission regulations imposed by governments and depleting fossil fuel reserves have promoted the development of the automotive industry towards novel technologies. Various types of hybrid power plants for transport and stationary applications have emerged. The methodology of design and development of such power plants varies according to power producing components used in the systems. The practical feasibility of such power plants is a pre-requisite to any further development. This work presents thermodynamic analysis and modelling of such a novel power plant, assesses its feasibility and further discusses the development of a suitable control system. The proposed system consists of a hybrid configuration of a solid oxide fuel cell and IC engine as the main power producing components. A reformer supplies fuel gas to the fuel cell while the IC engine is supplied with a liquid fuel. The excess fuel from the fuel cell anode and the oxygen-depleted air from cathode of the fuel cell are also supplied to the engine. This gas mixture is aspirated into the engine with the balance of energy provided by the liquid fuel. The fuel cell exhaust streams are used to condition the fuel in the engine to ensure minimum pollutants and improved engine performance. Both, fuel cell and engine share the load on the system. The fuel cell operates on a base load while the engine handles majority of the transient load. This system is particularly suitable for a delivery truck or a bus cycle. Models of the system components reformer, solid oxide fuel cell, IC engine and turbocharger were developed to understand their steady state and dynamic behaviour. These models were validated against sources of literature and used to predict the effect of different operating conditions for each component. The main control parameters for each component were derived from these models. A first law analysis of the system at steady state was conducted to identify optimum operating region, verify feasibility and efficiency improvement of the system. The results suggested reduced engine fuel consumption and a 10 % improvement in system efficiency over the conventional diesel engines. Further, a second law analysis was conducted to determine the key areas of exergy losses and the rational efficiency of the system at full load operating conditions. The results indicate a rational efficiency of 25.4 % for the system. Sensitivity to changes in internal exergy losses on the system work potential was also determined. The exergy analysis indicates a potential for process optimisation as well as design improvements. This analysis provides a basis for the development of a novel control strategy based on exergy analysis and finite-time thermodynamics. A dynamic simulation of the control oriented system model identified the transient response and control parameters for the system. Based on these results, control systems were developed based on feedback control and model predictive control theories. These controllers mainly focus on air and fuel path management within the system and show an improved transient response for the system. In a hierarchical control structure for the system, the feedback controllers or the model predictive controller can perform local optimisation for the system, while a supervisory controller can perform global optimisation. The objective of the supervisory controller is to determining the load distribution between the fuel cell and the engine. A development strategy for such a top-level supervisory controller for the system is proposed. The hybrid power plant proposed in this thesis shows potential for application for transport and stationary power production with reduced emissions and fuel consumption. The first and second law of thermodynamics can both contribute to the development of a comprehensive control system. This work integrates research areas of powertrain design, thermodynamic analysis and control design. The development and design strategy followed for such a novel hybrid power plant can be useful to assess the potential of other hybrid systems as well.
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Kumar, Sandeep. "Non-AXisymmetric Aerodynamic Design-Optimization System with Application for Distortion Tolerant Hybrid Propulsion." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613749886763596.
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Lin, Qing. "Small-Signal Modeling and Stability Specification of a Hybrid Propulsion System for Aircrafts." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103515.
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This work utilizes the small-signal impedance-based stability analysis method to develop stability assessment criteria for a single-aisle turboelectric aircraft with aft boundary-layer propulsion (STARC-ABL) system. The impedance-based stability analysis method outperforms other stability analysis methods because it does not require detailed information of individual components for system integration, therefore, a system integrator can just require the vendors to make the individual components meet the impedance specifications to ensure whole system stability. This thesis presents models of a generator, motor, housekeeping loads, and battery all with power electronics interface which form an onboard electrical system and analyzes the relationship between the impedance shape of each component and their physical design and control loop design. Based on the developed small-signal model of the turbine-generator-rectifier subsystem and load subsystem, this thesis analyzes the impact of electromechanical dynamics of the turbofan passed through the generator on the dc distribution system, concluding that the rectifier can mitigate the impact. Finally, to ensure the studied system stable operation during the whole flying profile, the thesis provides impedance specifications of the dc distribution system and verifies the specifications with several cases in time-domain simulations.<br>M.S.<br>Electric aircraft propulsion (EAP) technologies have been a trend in the aviation industry for their potential to reduce environmental emissions, increase fuel efficiency and reduce noise for commercial airplanes. Achieving these benefits would be a vital step towards environmental sustainability. However, the development of all-electric aircraft is still limited by the current battery technologies and maintenance systems. The single-aisle turboelectric aircraft with aft boundary-layer (STARC-ABL) propulsion concept is therefore developed by NASA aiming to bridge the gap between the current jet fuel-powered aircraft and future all-electric vehicles. The plane uses electric motors powered by onboard gas turbines and transfers the generated power to other locations of the airplane like the tail fan motor to provide distributed propulsion.
Power electronics-based converter converts electricity in one form of electricity to another form, for example, from ac voltage to dc voltage. This conversion of power is very important in the whole society, from small onboard chips to Mega Watts level electrical power system. In the aircraft electrical power system context, power electronics converter plays an important role in the power transfer process especially with the recent trend of using high voltage dc (HVDC) distribution instead of conventional ac distribution for the advantage of increased efficiency and better voltage regulation. The power generated by the electric motors is in ac form. Power electronics converter is used to convert the ac power into dc power and transfer it to the dc bus. Because the power to drive the electric motor to provide distributed propulsion is also in ac form, the dc power needs to be converted back into ac power still through a power electronics converter. With a high penetration of power electronics into the onboard electrical power system and the increase of electrical power level, potential stability issues resulted from the interactions of each subsystem need to be paid attention to. There are mainly two stability-related studies conducted in this work. One is the potential cross-domain dynamic interaction between the mechanical system and the electrical system. The other is a design-oriented study to provide sufficient stability margin in the design process to ensure the electrical system’s stable operation during the whole flying profile.
The methodology used in this thesis is the impedance-based stability analysis. The main analyzing process is to find an interface of interest first, then grouped each subsystem into a source subsystem and load subsystem, then extract the source impedance and load impedance respectively, and eventually using the Nyquist Criterion (or in bode plot form) to assess the stability with the impedance modeling results.
The two stability-related issues mentioned above are then studied by performing impedance analysis of the system. For the electromechanical dynamics interaction study, this thesis mainly studies the rotor dynamics’ impact on the output impedance of the turbine-generator-rectifier system to assess the mechanical dynamics’ impact on the stability condition of the electrical system. It is found that the rotor dynamics of the turbine is masked by the rectifier; therefore, it does not cause stability problem to the pre-tuned system. For the design-oriented study, this thesis mainly explores and provides the impedance shaping guidelines of each subsystem to ensure the whole system's stable operation. It is found that the stability boundary case is at rated power level, the generator voltage loop bandwidth is expected to be higher than 300Hz, 60˚ to achieve a 6dB, 45˚ stability margin, and load impedance mainly depends on the motor-converter impedance.
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Nakka, Sai Krishna Sumanth. "Co-design of Hybrid-Electric Propulsion System for Aircraft using Simultaneous Multidisciplinary Dynamic System Design Optimization." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1602153187738909.
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Sellers, Jerry Jon. "Investigation into hybrid rockets and other cost-effective propulsion system options for small satellites." Thesis, University of Surrey, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309201.
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Wu, Wei. "On the performance of fuel cell supercapacitor hybrid propulsion system for city bus use." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10042832/.
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Fuel Cell (FC) buses have been developed as a long term zero emission solution for city transportation and they have now reached levels of maturity to supplement the coming London 2020 Ultra Low Emission Zone implementation. A critical review of previous research in this field has highlighted promising potential for FC technologies applied to bus applications and also identified the associated challenges. This research analysed the current FC bus industry and addressed the most recent trend of applying FCs with hybrid technologies for city buses. This research developed a scaled laboratory Fuel Cell and Supercapacitor hybrid drivetrain model for investigating the design and performance of a low emission propulsion systems for city bus applications in its dynamic environment. The laboratory system has been used to validate a computer model to ensure it is suitably representative of practical and full sized FC bus power systems. A novel hybrid control strategy was developed for a FC hybrid system and evaluated with actual bus driving cycles. The power balancing strategy between multiple power sources in the FC hybrid system has been explored and investigated. The key finding of this research is that hybridising the FC with an energy storage medium showed superior performance over FC only system. Additionally, existing FC hybrid buses generally have an over-sized FC on-board which significantly increases the capital cost. A series of steps have been identified to determine the required FC / energy storage degree of hybridisation. An optimised degree of hybridisation for FC hybrid bus can potentially improve the system performance, reduce the size of the FC on-board and propulsion system costs.
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Geiß, Ingmar [Verfasser]. "Sizing of the Series Hybrid-electric Propulsion System of General Aviation Aircraft / Ingmar Geiß." München : Verlag Dr. Hut, 2021. http://nbn-resolving.de/urn:nbn:de:101:1-2021100123334382521757.
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Kroll, Douglas M. (Douglas Michael). "Using polymer electrolyte membrane fuel cells in a hybrid surface ship propulsion plant to increase fuel efficiency." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61909.
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Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M. in Engineering and Management)--Massachusetts Institute of Technology, Engineering Systems Division, System Design and Management Program, 2010.<br>Cataloged from PDF version of thesis.<br>Includes bibliographical references (p. 59).<br>An increasingly mobile US Navy surface fleet and oil price uncertainty contrast with the Navy's desire to lower the amount of money spent purchasing fuel. Operational restrictions limiting fuel use are temporary and cannot be dependably relied upon. Long term technical research toward improving fuel efficiency is ongoing and includes advanced gas turbines and integrated electric propulsion plants, but these will not be implemented fleet wide in the near future. The focus of this research is to determine if a hybrid fuel cell and gas turbine propulsion plant outweigh the potential ship design disadvantages of physically implementing the system. Based on the potential fuel savings available, the impact on surface ship architecture will be determined by modeling the hybrid fuel cell powered ship and conducting a side by side comparison to one traditionally powered. Another concern that this solution addresses is the trend in the commercial shipping industry of designing more cleanly running propulsion plants.<br>Douglas M. Kroll.<br>S.M.in Engineering and Management<br>Nav.E.
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Harmon, Frederick G. "Neural network control of a parallel hybrid-electric propulsion system for a small unmanned aerial vehicle /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2005. http://uclibs.org/PID/11984.
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Ollas, Fredrik, and Viðarsson Gestur Ernir. "Proposed Design and Feasibility Study of a Hybrid-Electric Propulsion System for a Ten Passenger Aircraft." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-264347.
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This study aims to propose a hybridized version of a propulsion system for a 10-passenger aircraft and compare it to a conventional (reference) aircraft which uses a fossil fuelled turbofan for propulsion. The hybridized powertrain includes a fossil fuelled gas turbine, which is only used for producing electricity, coupled in a series configuration with a battery storage, that provide power to two electrically ducted fans. The comparison mainly aims towards total energy consumption and carbon dioxide emissions; hence, these are aimed to be reduced in the hybridized solution. The aircrafts are compared when flying the same pre-defined route that is a 900 km long distance, cruising at an altitude of 7500 m at 150 m/s. Rate of climb, climb speed and descent angle are optimized, with regards to energy demand. The hybridized propulsion system is evaluated in three different scenarios, that is: 2020, Near Future- and Advanced Future scenario, which contain different component properties that address different future predictions. An experiment is conducted with a small scale electrical ducted fan, operating in a wind tunnel, to measure different quantities such as power and thrust. These results are then scaled up and used as design parameters for a proposed fan design that is of sufficient size to propel the hybridized aircraft. The results show that the hybridized concept, at design conditions, proves feasible in all scenarios. The mass of the aircraft increases as the hybridized system is introduced, but nevertheless the fuel consumption decreases where the reduction depends highly on energy density of the batteries.<br>Målet med den här studien är att föreslå en el-hybridiserad version av ett framdrivningssystem för ett passagerarflygplan om 10 personer, och jämföra det med ett konventionellt (referens) flygplan som använder fossildrivna turbofläktmotorer för framdrift. Det el-hybridiserade framdrivningssystemet består utav en fossildriven gasturbin vars syfte är att generera elektricitet, kopplat i en seriell konfiguration med ett batterilager, som förser två elektriskt drivna kanaliserade fläktar. Jämförelsen syftar framförallt till energiförbrukning och koldioxidutsläpp; därav, målet är att reducera dessa i el-hybrid lösningen. Flygplanen jämförs när de presterar samma förutbestämda rutt som är 900 km lång, har en kryssning altitud på 7500 m i 150 m/s. Andra rutt parametrar är optimerade, med hänsyn till energiförbrukning. Det el-hybridiserade framdrivningssystemet är utvärderat i tre olika scenarier, som är: 2020- , Near Future- och Anvanced Future scenario, som alla innebär olika komponentegenskaper som representerar olika framtida förutsägelser. Ett experiment är utfört med en småskalig elektrisk kanaliserad fläkt, som körs i en vindtunnel, för att mäta kvantiteter som effekt och framdrivningskraft. Dessa resultat är sedan skalade upp och använda som designparametrar för en föreslagen fläkt design som är tillräckligt stor för att driva det el-hybridiserade flygplanet. Resultaten visar att det el-hybridiserade konceptet, under designförhållandena, visar sig vara möjlig i alla scenarier. Vikten av flygplanet ökar när det el-hybridiserade konceptet är applicerat, men bränsleförbrukningen minskar ändå, där mängden reducerat bränsle i allra högsta grad beror på energi-densiteten i batterierna.
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Chakravarthula, Venkata Adithya. "Transient Analysis of a Solid Oxide Fuel Cell/ Gas Turbine Hybrid System for Distributed Electric Propulsion." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1484651177170392.
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Bacciaglia, Antonio. "Design and Development of a Propulsion System for a Water-Air Unmanned Vehicle." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2018.
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This work aims to contribute on the design of a Bimodal Unmanned Underwater and Air System (BUUAS). This research project will first present background informations of current hybrid UAV concepts with a focus on the different types of propulsion mechanisms used in air/water transition. Then a brief description of BUUAS will lead to requirements for the transition mechanism that this work aims to develop. After a section dedicated to the description of a short-impulse thruster layout, theoretical and experimental approaches are used to determine the amount of thrust generated. As second design step, a simplified UAV version is used to test the transition phase using the designed thruster. Finally, a section is dedicated to a design layout description with the thruster and an optimized propeller. Future work is proposed to continue in the development of this project, with a short description of folding wing and propulsion system integration concepts.
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Beckman, Mathias, and Gerald Volden Alex Christy. "Performance Assessment of Electrical Motor for Electric Aircraft Propulsion Applications : Evaluation of the Permanent Magnet Motor and its Limitations in Aircraft Propulsion." Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-45157.
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This thesis project will evaluate which kind of electrical motor is best suited for aircraft propulsion and which parameters effect the efficiency. An economic analysis was conducted, comparing the fuel price (Jet A1) for a gas turbine and the electricity price for an electric motor of 1MW. The study was conducted by using analytical methods in MATLAB. Excel was used to compile and present the data. The data used in this thesis project were assumed with regards to similar studies or pre-determined values. The main losses for the Permanent Magnet Synchronous Motor (PMSM) were calculated to achieve a deeper understanding of the most important parameters and how these parameters need to improve to allow for future electric propulsion systems. The crucial parameters for the losses were concluded to be the temperature, voltage level, electrical frequency, magnetic flux density, size of the rotor and rotational speed. The three main losses of a PMSM was illustrated through the analytical equations used in MATLAB. The calculations present how the ohmic losses depend on the temperature (0-230°C) at different voltages (700V and 1000V), how the core losses depend on frequency (0-1000Hz) at different magnetic flux densities and how the windage losses depend on rotational speed (7000-10000 rpm). It could be concluded that at 8500 rpm an efficiency of 91,26% could be achieved at 700V, 1.5T and 90.4% at 1000V, 1.65T. The decrease in efficiency is a result of the increase in magnetic flux density. When looking at the economic viability of electrical integration the power to weight ratio and energy price was compared for the gas turbine and electrical motor including an inverter and battery. This resulted in a conclusion that a pure electrical system may not compete with a gas turbine in 30 years of time due to the low energy density of the battery. It was also concluded that the emissions during cruise could be lowered significantly. If the batteries were charged in Sweden the emissions would decrease from ~937 kg CO2 to ~31 kg CO2. If the batteries were charged in the Nordic region the emissions would decrease to ~119kg CO2. However, if the batteries were to be charged in the US the carbon dioxide emission would be ~1084 kg CO2, which is an increase in CO2 emission compared to the gas turbine.
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Zubieta, Luis Eduardo. "Design of a propulsion system with double-layer power capacitors and soft-switched converters for a hybrid automobile." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ58962.pdf.
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Dai, Ping. "Réjection de perturbation sur un système multi-sources - Application à une propulsion hybride." Thesis, Poitiers, 2015. http://www.theses.fr/2015POIT2251/document.
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Ce mémoire porte sur l'étude d'un système de gestion d'énergie électrique dans un système multi-sources soumis à des perturbations exogènes. L'application visée est l'alimentation d'une propulsion hybride diesel/électrique équipée d'un système d'absorption des pulsations de couple. Les perturbations exogènes considérées peuvent être transitoires ou persistantes. Une perturbation transitoire correspond à une variation rapide du couple de charge, due par exemple à une accélération ou une décélération du véhicule. Une perturbation persistante provient du système de compensation des pulsations de couple générées par le moteur thermique. Le premier objectif du contrôle est de maintenir constante la tension du bus continu. Le deuxième objectif est d'absorber dans un système de stockage rapide constitué de super condensateur ces perturbations qui peuvent à terme provoquer une usure prématurée de la batterie. Le troisième objectif est de compenser l'auto-décharge dans le super condensateur en maintenant constante sa tension nominale. Les deux sources (batterie et super condensateur) sont reliées au bus continu par l'intermédiaire de deux convertisseurs boost DC/DC. La commande consiste à piloter les rapports cycliques de chaque convertisseur. C'est un système non linéaire où la commande est multiplicative de l'état. L'approche classique consistant à résoudre les équations Francis-Byrnes-Isidori ne s'applique pas directement dans ce cas où la sortie et la matrice d'interconnection dépendent de la commande. De plus, si cette approche est bien adaptée au rejet de perturbations persistantes, elle montre ces limites pour le rejet de perturbations non persistantes combiné à des objectifs de régulation. Notre approche a consisté à écrire le système sous un formalisme Port-Controlled Hamiltonian et à s'affranchir de la contrainte de la dépendance de la matrice d'interconnection avec la commande en utilisant la théorie des perturbations singulières. La commande du système dégénéré peut ensuite être calculée par une approche passive. Les performances de cette commande ont été testées en simulation et à l'aide d'un banc d'essai expérimental. Les résultats montrent l'efficacité du système d'absorption des différents types de perturbation tout en respectant les deux objectifs de régulation<br>This thesis presents the research of energy management in a battery/ultracapacitor hybrid energy storage system with exogenous disturbance in hybrid electric vehicular application. Transient and harmonic persistent disturbances are the two kinds of disturbances considered in this thesis. The former is due to the transient load power demand during acceleration and deceleration, and the latter is introduced from the process of the internal combustion engine torque ripples compensation. Our control objective is to absorb the disturbances causing battery wear via the ultracapacitor, and meanwhile, to maintain a constant DC voltage and to compensate the self-discharge in the ultracapacitor to maintain it operating at the nominal state of charge. The object system is nonlinear due to the multiplicative relation between the input and the state. The traditional approach to solve Francis-Byrnes-Isidori equations cannot be directly applied in this case since the interconnect matrix depends on the control input. Besides, even if this approach is well suited to the rejection of persistent disturbances, it shows the limits for the case of non-persistent disturbances which is also our object. Our contributed control method is realized through a cascade control structure based on the singular perturbation theory. The ultracapacitor current with the fastest motion rate is controlled in the inner fast loop through which we impose the desired dynamic to the system. The reduced system controlled in the outer slow loop is a Hamiltonian system and the controller is designed via interconnection and damping assignment. Simulations and experiments have been carried out to evaluate the control performance. A contrast of the system responses with and without the control algorithm shows that, with the control algorithm, the ultracapacitor effectively absorbs the disturbances; and verifies the effectiveness of the control algorithm
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Paulson, Thomas A. W. "Supporting the prescription of exercise in spinal cord injured populations." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/13454.
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Following a spinal cord injury (SCI), participation in regular exercise can enhance physical capacity and performance in activities of daily living. With this in mind, the use of subjective ratings of perceived exertion (RPE) may provide an easy-to-administer alternative to traditional methods of regulating exercise intensity (e.g. heart rate and power output (PO)). A physically active lifestyle is also associated with a reduced risk of cardiovascular disease, in part because exercise exerts anti-inflammatory effects. Examining the plasma response of inflammation-mediating chemical messengers, known as cytokines, to traditional and novel exercise modalities may help maximise the anti-inflammatory potential of regular exercise. Participants with a cervical level SCI successfully self-regulated a 20 min bout of moderate intensity wheelchair propulsion (Chapter three). No differences in physiological or PO responses were observed during the imposed-intensity and self-regulated wheelchair propulsion in the trained population group. In a non-SCI group of novice wheelchair-users, a differentiated RPE specific to the exercising muscle mass (RPEP) was the dominant perceptual signal during submaximal wheelchair propulsion (Chapter four). The novice group successfully self-regulated a 12 min bout of moderate intensity wheelchair propulsion, comprising of a discontinuous 3 x 4 min protocol, using differentiated RPEP. In contrast, a more accurate self-regulation of light intensity wheelchair propulsion was observed when employing traditional overall RPE compared to RPEP. Following strenuous wheelchair propulsion, plasma concentrations of the inflammation-mediating cytokine interleukin-6 (IL-6) were significantly elevated in non-SCI and thoracic level SCI participants (Chapter five). Impaired sympathetic nervous system (SNS) function was associated with a reduced IL-6 response in participants with a cervical level SCI. The plasma IL-6 response to 30 min moderate intensity (60% VO2peak) arm-crank ergometry (ACE) was associated with an elevation in the anti-inflammatory cytokine IL-1 receptor antagonist (IL-1ra) independent of SNS activation (Chapter six). Light intensity ACE resulted in a small, significant plasma IL-6 response but no IL-1ra response. The addition of functional electrical stimulation-evoked lower-limb cycling to concurrent hand cycling, termed hybrid exercise, resulted in a greater plasma IL-6 response compared to moderate intensity hand cycling alone in participants with a thoracic level SCI (Chapter seven).
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Collin, Philippe. "Design, taking into account the partial discharges phenomena, of the electrical insulation system (EIS) of high power electrical motors for hybrid electric propulsion of future regional aircrafts." Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30116.
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La réduction des émissions de CO2 est un enjeu majeur pour l'Europe dans les années à venir. Les transports sont aujourd'hui à l'origine de 24% des émissions globales de CO2. L'aviation ne représente que 2% des émissions globales de CO2. Cependant, le trafic aérien est en pleine expansion et, déjà, des inquiétudes apparaissent. A titre d'exemple, en Suède, depuis les années 1990, les émissions de CO2 dues au trafic aérien ont augmenté de 61%. Ce constat explique l'apparition du mouvement "Flygskam" qui se repend dans de plus en plus de pays Européen. C'est dans ce contexte que l'Union Européenne a lancé en septembre 2016 le projet Hybrid Aircraft Academic research on Thermal and Electrical Components and Systems (HASTECS). Le consortium regroupe différents laboratoires et Airbus. Ce projet s'inscrit dans le programme "Clean Sky 2" qui vise à développer une aviation plus verte. L'objectif ambitieux est de réduire de 20% les émissions de CO2 et le bruit produits par les avions d'ici 2025. Pour cela, le consortium étudie une architecture hybride de type série. La propulsion est assurée par des moteurs électriques. Deux cibles ont été définies. En 2025, les moteurs doivent atteindre une densité de puissance de 5kW/kg, système de refroidissement inclus. En 2035, la densité de puissance des moteurs sera doublée pour atteindre 10kW/kg. Pour atteindre ces cibles, le niveau de tension sera considérablement augmenté, au-delà du kilovolt. Le risque de décharges électriques dans les stators des moteurs électriques est considérablement accru. L'objectif de cette thèse est de mettre au point un outil d'aide au design du Système d'Isolation Electrique (SIE) primaire du stator de moteur électrique piloté par convertisseur. Elle est découpée en cinq parties. La première partie commence par préciser les enjeux et défis d'une aviation plus verte. Le SIE du stator de moteur électrique est développé. Enfin, les contraintes qui s'appliquent sur le SIE dans l'environnement aéronautique sont identifiées. La deuxième partie présente les différents types de décharges électriques que l'on peut retrouver. Le principal risque vient des Décharges Partielles (DP) qui détériorent peu à peu le SIE. Le principal mécanisme pour expliquer l'apparition des DP est l'avalanche électronique. Le critère de Paschen permet d'évaluer le Seuil d'Apparition des Décharges Partielles (SADP). Différentes techniques permettent de détecter et mesurer l'activité des DP. Des modèles numériques permettent d'évaluer le SADP. La troisième partie présente une méthode originale pour déterminer les lignes de champ électrique dans un problème électrostatique. Elle n'utilise qu'une formulation en potentiel scalaire. La quatrième partie présente une étude expérimentale pour établir une correction du critère de Paschen. Un bobinage de moteur électrique est très loin des hypothèses dans lesquelles ce critère a été originellement défini. Enfin, la cinquième partie est consacrée à l'élaboration de l'outil d'aide au design du SIE. Des abaques sont construites afin de fournir des recommandations sur le dimensionnement des différents isolants dans une encoche de stator. Une réduction du SADP due à une variation combinée de la température et de la pression est prise en compte<br>Reducing CO2 emissions is a major challenge for Europe in the years to come. Nowadays, transport is the source of 24% of global CO2 emissions. Aviation accounts for only 2% of global CO2 emissions. However, air traffic is booming and concerns are emerging. For instance, CO2 emissions from air traffic have increased by 61% in Sweden since the 1990s. This explains the emergence of the "Flygskam" movement which is spreading in more and more European countries. It is in this context that the European Union launched in September 2016 the project Hybrid Aircraft Academic research on Thermal and Electrical Components and Systems (HASTECS). The consortium brings together different laboratories and Airbus. This project is part of the program "Clean Sky 2" which aims to develop a greener aviation. The ambitious goal is to reduce CO2 emissions and the noise produced by aircraft by 20% by 2025. To do that, the consortium is studying a serial hybrid architecture. Propulsion is provided by electric motors. Two targets are defined. In 2025, the engines must reach a power density of 5kW/kg, including the cooling system. In 2035, the power density of the engines will be doubled to reach 10kW/kg. To reach these targets, the voltage level will be considerably increased, beyond one kilovolt. The risk of electric discharges in the stators of electric motors is considerably increased. The objective of this thesis is to develop a tool to assist in the design of the primary Electrical Insulation System (EIS) of the stator of an electric motor controlled by a converter. It is organized in 5 parts. The first part begins by clarifying the issues and challenges of a greener aviation. The electric motor stator EIS is developed. Finally, the constraints that apply to the EIS in the aeronautical environment are identified. The second part presents the different types of electric discharges that can be found. The main risk comes from Partial Discharges (PD) which gradually deteriorate the EIS. The main mechanism for explaining the appearance of PD is the electronic avalanche. The Paschen criterion makes it possible to evaluate the Partial Discharge Inception Voltage (PDIV). Different techniques are used to detect and measure the activity of PD. Numerical models are used to evaluate the PDIV. The third part presents an original method for determining the electric field lines in an electrostatic problem. It only uses a scalar potential formulation. The fourth part presents an experimental study to establish a correction of the Paschen criterion. An electric motor winding is very far from the hypotheses in which this criterion was originally defined. Finally, the fifth part is devoted to the development of the SIE design aid tool. Graphs are generated to provide recommendations on the sizing of the various insulators in a stator slot. A reduction in the PDIV due to a combined variation in temperature and pressure is taken into account
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Khanna, Yash. "Conceptual design and development of thermal management system for hybrid electric aircraft engine. : A study to develop a physical model and investigate the use of Mobil Jet Oil II as coolant for aircraft electrical propulsion under different scenarios and time horizons." Thesis, Mälardalens högskola, Framtidens energi, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-46612.
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The ever-increasing levels of greenhouse gas emissions has led to the scientific community starting to explore the viability of electrical aircraft system, with the most prominent research and product development for hybrid electric system, which forms the transition phase from combustion to fully electric aircrafts. The primary objective of this thesis is to find solutions towards thermal management of the electrical components of a hybrid electric aircraft propulsion system, which generate a significant amount of heat while operating at heavy load conditions required to propel an aircraft. In view of these objectives a micro channel cold plate liquid cooling system, has been dynamically modelled using a combination of lumped parameter and thermal resistance methods of heat transfer analysis. The study investigates the prospects of using Mobil Jet Oil II, typically used as an aircraft lubricant as a coolant for the thermal management system. The primary components of this model are lithium ion battery, DC-AC inverter, permanent magnet motor, cross flow finned micro channel heat exchanger, centrifugal pump and ducts. The electrical components have been dimensioned according to energy storage and load requirements considering their efficiencies and gravimetric power/energy. The system has been simulated and analyzed under different scenarios considering the coolant inlet temperature, air temperature across the heat exchanger and on two-time horizons. Analysis has been done to study the dynamic trends of the component temperature and the coolant at different stages of the system. The scope of the study includes an evaluation of the added weight of the thermal management system under different time horizons and their comparison with results from a reference study. From the simulation results it can be concluded that Mobil Jet Oil II is a promising option as a coolant and therefore its use as a common fluid for gas turbine lubrication and as coolant, will benefit the aircraft as now no extra coolant reservoir is required, allowing reduction in weight carried by the aircraft.
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Friedrich, Christian. "Hybrid-electric propulsion systems for aircraft." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708913.
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Zhao, Jianning. "Co-Optimisation du Dimensionnement et du Contrôle des Groupe Motopropulseurs Innovants." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLC057/document.
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Des technologies avancées sont très demandées dans l'industrie automobile pour respecter les réglementations de consommation de carburant de plus en plus rigoureuses. La co-optimisation du dimensionnement et du contrôle des groupes motopropulseurs avec une efficacité de calcul améliorée est étudiée dans cette thèse.Les composants des groupes motopropulseurs, tels que le moteur, la batterie et le moteur électrique, sont modélisés analytiquement au niveau descriptif et prédictif afin de permettre une optimisation du contrôle rapide et une optimisation du dimensionnement scalable. La consommation d'énergie minimale des véhicules hybrides-électriques est évaluée par des nouvelles méthodes optimales. Ces méthodes – y compris Selective Hamiltonian Minimization et GRaphical-Analysis-Based energy Consumption Optimization – permettent d'évaluer une consommation minimale d'énergie avec une efficacité de calcul améliorée. De plus, la méthode de Fully-Analytic energy Consumption Evaluation (FACE) approxime la consommation d'énergie minimale sous forme analytique en fonction des caractéristiques de la mission et des paramètres de conception des composants du groupe motopropulseur. Plusieurs cas d’études sont présentées en détail par rapport aux approches de co-optimisation à bi-niveaux et à uni-niveau, ce qui montre une réduction efficace du temps de calcul requis par le processus global de co-optimisation<br>Advanced technologies are highly demanded in automotive industry to meet the more and more stringent regulations of fuel consumption. Cooptimization of design and control for vehicle propulsion systems with an enhanced computational efficiency is investigated in this thesis.Powertrain components, such as internal combustion engines, batteries, and electric motor/generators, are analytically modeled at descriptive and predictive level correspondingly for the development of fastrunning control optimization and for the scalability of design optimization. The minimal fuel consumption of a hybrid-electric vehicle is evaluated through novel optimization methods. These methods – including the Selective Hamiltonian Minimization, and the GRaphical-Analysis-Based energy Consumption Optimization – are able to evaluate the minimal energy consumption with the enhanced computational efficiency. In addition, the Fully-Analytic energy Consumption Evaluation method approximates the minimal energy consumption in closed form as a function of the mission characteristics and the design parameters of powertrain components.A few case studies are presented in details via the bi-level and uni-level co-optimization approaches, showing an effective improvement in the computational efficiency for the overall co-optimization process
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Accorinti, Flavio. "Two-Phase Power Electronics Cooling Solution Design in Air Context Answering to the Objectives of the Hybrid Aircraft 2035 High-efficiency cooling system for highly integrated power electronics for hybrid propulsion aircraft Systèmes diphasiques pour le contrôle ther- mique de l’électronique de puissance Steady-state analysis of a capillary pumped loop for terrestrial application with methanol and ethanol as working fluids Experimental and Numerical Analysis of Start-Up of a Capillary Pumped Loop for Terrestrial Applications." Thesis, Chasseneuil-du-Poitou, Ecole nationale supérieure de mécanique et d'aérotechnique, 2020. http://www.theses.fr/2020ESMA0005.
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Le monde aérien est lui aussi destiné à réduire drastiquement son empreinte environnementale. Cela passe pour partie par l’innovation technologique et la réduction de l’énergie nécessaire à la propulsion. Dans cet objectif, les travaux relatés dans ce mémoire s’inscrivent dans un projet de recherche (Clean Sky 2-HASTECS) visant le développement de propulsion hybride mettant à profit les performances d’une chaîne électrique. Les puissances mises en jeu requièrent de revisiter les solutions de refroidissement pour atteindre les spécifications de puissance massique envisagées à l’horizon 2035. Nous nous intéressons ici à la gestion thermique de l’électronique de puissance qui vise une puissance massique de 25kW/kg à cet horizon.Le travail effectué, essentiellement numérique, est lié à la recherche, au dimensionnement, à l’optimisation, et à l’analyse d’une technologie de refroidissement efficace, caractérisée par une faible masse et capable de contrôler la température des composants électroniques dans les conditions opératoires les plus drastiques. Différentes technologies de refroidissement, actives mono et diphasiques et passives, à pompage capillaire, ont été analysées et comparées sur la base de données disponibles dans la littérature et d’un dimensionnement de première approximation : la solution la plus adaptée a été choisie en utilisant comme critère sa masse spécifique. La solution finalement retenue et présentant le meilleur indice de masse spécifique global est une boucle diphasique CPLIP (Capillary Pumped Loop for Integrated Power), par ailleurs pourvues des caractéristiques thermiques et hydrauliques uniques. Après son dimensionnement, la CPLIP a été optimisée pour répondre aux objectifs à deux horizons successifs, 2025 et 2035 (mentionnons un travail itératif avec les chercheurs responsables du développement de l’électronique permettant une optimisation mutuelle). L’attention a été en particulier concentrée sur le condenseur, le composant le plus lourd de la boucle. La solution 2025 est caractérisée par un condenseur classique air-méthanol, et a démontré sa capacité d’aller au-delà du seuil de 15 kW/kg demandé. La solution 2035, caractérisée par un concept de condenseur innovant : à micro-canaux et à ailettes à persiennes, a permis d’obtenir, après ce travail de co-dimensionnement thermique-électronique, des valeurs de puissance spécifique doubles par rapport à l’objectif 2035. Dans cette thèse, les caractéristiques hydrauliques et thermiques de la boucle CPLIP ont été analysées expérimentalement sur un prototype issu d’études antérieures, et numériquement à l’aide d’un modèle CFD ainsi qu’à l’aide d’un modèle 0D innovant. Les résultats démontrent l’aptitude de la CPLIP à gérer thermiquement l’électronique de puissance pour des cycles de mission d’un avion court ou moyen-courrier, caractérisés par des changements brutaux de puissance thermique, tout en assurant le contrôle de la température des modules électroniques.Enfin, une étude a été conduite portant sur le comportement transitoire de la boucle, en particulier lors des démarrages sévères à très hautes puissances, ainsi que pendant des cycles d’accélérations sévères qui caractérisent ce champ d’application. Dans le premier cas, une étude expérimentale et numérique a été menée pour démontrer la capacité de la boucle à démarrer dans les conditions thermiques et environnementales les plus difficiles (haute puissance de démarrage et haute température environnementale). Dans le deuxième cas, une étude numérique a été utilisée pour comprendre quel est le comportement de la boucle quand des champs d’accélérations, jusqu’à 10g, perturbent ses conditions opératoires. Ce travail ouvre des perspectives très intéressantes tant du point de vue de l’application que vis-à-vis de la nécessité aujourd’hui d’adopter des approches de recherche couplées pour dimensionner simultanément thermiquement et électriquement l’électronique de puissance<br>Technological innovation and reduction of the energy required for propulsion is necessary to reduce aircrafts environmental impact. The present work is part of the research project Clean Sky 2 – HASTECS, which purpose is the development of a hybrid propulsion aircraft. The high powers involved make classical cooling solutions obsolete, in terms of efficiency, and not suitable for the power to mass ratio required for the target 2035. In particular, the problem related to power electronics cooling is assessed in this work with the purpose to achieve a performance coefficient of 25 kW/kg.This work, essentially numerical, is linked to the research, design, optimisation and analysis of a high efficiency cooling system, able to control power electronics components temperature, operating in pretty severe conditions (high thermal power density, >15kW; cyclic variation of cold source temperature and severe transient phases) and which has to be lightweight to ensure performance coefficient requirements. Different cooling technologies, active single and two-phase and passive capillary driven, have been analysed and compared on the basis of literature data and of a first approximation design: the most adapted solution has been chosen on the base of its specific power [kW/kg]. The solution that has been finally retained is a Capillary Pumped Loop for Integrated Power (CPLIP), which thermal characteristics are quite interesting and unique. After its design, the loop has been optimised to answer to objectives of 2025 and 2035. It is worth of attention the work carried out in collaboration with power electronics team of the same project to achieve a mutual optimisation of the systems. Concerning the thermal side, the attention was focused on the condenser, the heaviest component in the loop. The 2025’s solution is characterised by a classical flat plate air-methanol condenser which allowed to cross over the threshold of 15kW/kg for 2025. 2035’s solution, on the contrary, is characterised by an innovative condenser typology, using microchannels on methanol side and louvered fins on air side, allowing to obtain more than double of the power coefficient required! In this work, thermal and hydraulic characteristics of the CPLIP have been experimentally analysed, using a prototype deriving from previous studies, and by using CFD and a 0D model. Results show the ability of the CPLIP to control the temperature of power electronics modules during a short and medium-range aircraft mission profile, characterised by sudden changes of thermal load and cyclic variations of the cold source temperature.Finally, a study focused on the transient behaviour of the loop has been carried out. In particular, the start-up of the CPLIP and its behaviour during sudden and violent acceleration stages, characterising this application filed, have been exploited. In the first case, an experimental and a numerical study were carried out to demonstrate the ability of the loop to starts its operation in the most difficult thermal and environmental conditions (high thermal load and high environmental temperature). In the second case, a numerical study has been performed to understand the behaviour of the loop when an acceleration field up to 10g perturbs its operations.This work opens new interesting perspectives stand points concerning the application itself and the necessity to adopt a multidisciplinary approach to simultaneously thermally and electronically design new generation power electronics
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Dinca, Dragos. "Development of an Integrated High Energy Density Capture and Storage System for Ultrafast Supply/Extended Energy Consumption Applications." Cleveland State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=csu1495115874616384.
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Dreier, Dennis. "Assessing the potential of fuel saving and emissions reduction of the bus rapid transit system in Curitiba, Brazil." Thesis, KTH, Energi och klimatstudier, ECS, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176398.
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The transport sector contributes significantly to global energy use and emissions due to its traditional dependency on fossil fuels. Climate change, security of energy supply and increasing mobility demand is mobilising governments around the challenges of sustainable transport. Immediate opportunities to reduce emissions exist through the adoption of new bus technologies, e.g. advanced powertrains. This thesis analysed energy use and carbon dioxide (CO2) emissions of conventional, hybrid-electric, and plug-in hybrid-electric city buses including two-axle, articulated, and biarticulated chassis types (A total of 6 bus types) for the operation phase (Tank-to-Wheel) in Curitiba, Brazil. The systems analysis tool – Advanced Vehicle Simulator (ADVISOR) and a carbon balance method were applied. Seven bus routes and six operation times for each (i.e. 42 driving cycles) are considered based on real-world data. The results show that hybrid-electric and plug-in hybrid-electric two-axle city buses consume 30% and 58% less energy per distance (MJ/km) compared to a conventional two-axle city bus (i.e. 17.46 MJ/km). Additionally, the energy use per passenger-distance (MJ/pkm) of a conventional biarticulated city bus amounts to 0.22 MJ/pkm, which is 41% and 24% lower compared to conventional and hybrid-electric two-axle city buses, respectively. This is mainly due to the former’s large passenger carrying capacity. Large passenger carrying capacities can reduce energy use (MJ/pkm) if the occupancy rate of the city bus is sufficient high. Bus routes with fewer stops decrease energy use by 10-26% depending on the city bus, because of reductions in losses from acceleration and braking. The CO2 emissions are linearly proportional to the estimated energy use following from the carbon balance method, e.g. CO2 emissions for a conventional two-axle city bus amount to 1299 g/km. Further results show that energy use of city bus operation depends on the operation time due to different traffic conditions and driving cycle characteristics. An additional analysis shows that energy use estimations can vary strongly between considered driving cycles from real-world data. The study concludes that advanced powertrains with electric drive capabilities, large passenger carrying capacities and bus routes with a fewer number of bus stops are beneficial in terms of reducing energy use and CO2 emissions of city bus operation in Curitiba.
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Schömann, Joachim [Verfasser]. "Hybrid-Electric Propulsion Systems for Small Unmanned Aircraft / Joachim Schömann." München : Verlag Dr. Hut, 2014. http://d-nb.info/1063222060/34.
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Vieira, Giovani Giulio Tristão Thibes. "Hybrid powertrains analysis for ship propulsion using energy storage." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3143/tde-17122018-090614/.
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The ship emission already occupy the eighth position in the world biggest emitters ranking. This happens because the ship operations have a huge demand variation therefore in order to reduce the ship emissions is required an efficient operation of the generators. This work aims at integrating advanced storage systems into the operation of diesel generators. The variation of the operation point has a direct interference on the emissions and on the diesel consumption, this variation is allowed through the frequency and voltage control. The use of lithium batteries for various operation points of the generators is analyzed. The use of an energy storage system allowed the operation of the generators in a better operation point therefore there was a reduction in diesel consumption and in CO2 emissions when the diesel generators. The main result of this work could also shed light in the operation of isolated power systems equipped with advanced storage systems and diesel generators.<br>As emissões dos navios já ocupam a oitava posição entre os países com maior emissão no mundo. Isso pode ser explicado pelo fato de que as operações dos navios têm uma grande variação de demanda de potência, com isso a operação inteligente dos geradores a diesel é fundamental para a redução das emissões. A abordagem desenvolvida nesse trabalho integra o uso de sistemas de armazenamento avançados na operação dos geradores a diesel. A variação do ponto de operação dos geradores a diesel interfere diretamente no consumo e nas emissões, essa variação só é possível por meio do controle de frequência e tensão providos pelo sistema de armazenamento de energia. Nesse trabalho foram analisados o uso de baterias de lítio para diferentes pontos de operação do gerador a diesel. O uso das baterias possibilitou a operação dos geradores num melhor ponto de carga com isso houve uma redução das emissões e do consumo de combustível. Os resultados encontrados nesse trabalho podem ser extrapolados qualitativamente para outros sistemas de potência offshore, como plataformas de petróleo e de perfuração, que operem com sistemas de baterias avançadas e geradores a diesel.
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Bassam, Ameen. "Use of voyage simulation to investigate hybrid fuel cell systems for marine propulsion." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/412705/.
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The design of green ships has received significant attention with the goal of reducing the negative environmental impacts of shipping and to comply with the more stringent environmental regulations. Therefore, in 2009 the International Maritime Organisation (IMO) published the Energy Efficiency Design Index (EEDI) measures to be adopted by new ships to reduce the Greenhouse Gases (GHG). Hybrid electric power and propulsion is one of the EEDI measures and fuel cell technologies are considered as a candidate to be used due to their high efficiency, lower emissions, lower maintenance, and quiet operation. This project aims to investigate the use of hybrid propulsion systems for marine propulsion which utilise fuel cells as a main source of power and the effect of energy management on the performance of these systems through voyage simulation. In order to assess the effectiveness of fuel cells as a source of power for ship propulsion systems, the development of a time-domain three degree of freedom total ship system simulator using MATLAB/Simulink is completed. Different components of the ship, including its propulsion system, and the ship's interaction with the surrounding environment are mathematically modelled. Considered power sources in the thesis include conventional two and four-stroke diesel engines, fuel cells and batteries to enable the comparison between conventional and hybrid fuel cell power trains. The verification and validation of the developed ship system simulator are also conducted using numerical, experimental and real ship operational data. The thesis demonstrates the use of the developed total ship system simulator in proposing a hybrid fuel cell/battery propulsion system for a domestic ferry. The results indicate that the hybrid fuel cell system has less weight and requires less space than the conventional diesel system. However, the hybrid fuel cell system's associated costs are still higher than diesel propulsion system. For hybrid fuel cell systems, the design of a suitable energy management strategy is essential in order to handle properly the required power split between the fuel cell and the battery systems. Therefore, the developed ship system simulator is also used to study and compare the most common energy management strategies. An improvement to the classical proportional-integral controller based strategy is presented in this thesis. This improvement results in minimizing the fuel cell operational stress and hydrogen consumption. Alongside this work, a novel multi-scheme energy management strategy with a main objective of reducing the total consumed energy is also developed for the world's first fuel cell passenger ship.
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Rajkumar, Vishnu Ganesh. "Design Optimization of a Regional Transport Aircraft with Hybrid Electric Distributed Propulsion Systems." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/84494.
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In recent years, there has been a growing shift in the world towards sustainability. For civil aviation, this is reflected in the goals of several organizations including NASA and ACARE as significantly increased fuel efficiency along with reduced harmful emissions in the atmosphere. Achieving the goals necessitates the advent of novel and radical aircraft technologies, NASA's X-57, is one such concept using distributed electric propulsion (DEP) technology.
Although practical implementation of DEP is achievable due to the scale invariance of highly efficient electric motors, the current battery technology restricts its adoption for commercial transport aircraft. A Hybrid Electric Distributed Propulsion (HEDiP) system offers a promising alternative to the all-electric system. It leverages the benefits of DEP when coupled with a hybrid electric system. One of the areas needing improvement in HEDiP aircraft design is the fast and accurate estimation of wing aerodynamic characteristics in the presence of multiple propellers. A VLM based estimation technique was developed to address this requirement.
This research is primarily motivated by the need to have mature conceptual design methods for HEDiP aircraft. Therefore, the overall research objective is to develop an effective conceptual design capability based on a proven multidisciplinary design optimization (MDO) framework, and to demonstrate the resulting capability by applying it to the conceptual design of a regional transport aircraft (RTA) with HEDiP systems.<br>Master of Science
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Stoddard, Rob L. "Experimental Investigation of N2O/O2 Mixtures as Volumetrically Efficient Oxidizers for Small Spacecraft Hybrid Propulsion Systems." DigitalCommons@USU, 2019. https://digitalcommons.usu.edu/etd/7690.
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A hybrid thruster system utilizes propellants in two different stages, traditionally a solid fuel and a gaseous or liquid oxidizer. Recently hybrid thrusters have become a popular topic of research due to the high demand of a ”green” replacement for hydrazine. Not only are hybrid thruster systems typically much safer than hydrazine, but they are also a low-cost system with a high reliability in performance. The Propulsion Research Laboratory (PRL) at Utah State University (USU) has developed a hybrid thruster system using 3-D printed acrylonitrile butadiene styrene (ABS) as the fuel and gaseous oxygen (GOX) as the oxidizer. This system has been spaceflight flown and tested in a hard vacuum environment with success. However, GOX has a low density and must be stored at high pressures to be considered viable. This thesis investigates the use of N2O/O2 mixtures, ”Nytrox”, and more commonly known as ”laughing gas”, as a higher density replacement oxidizer for GOX. Ina manner directly analogous to the creation of soda-water using dissolved carbon dioxide, Nytrox is created by bubbling gaseous oxygen under high pressure into nitrous oxide until the solution reaches saturation level. Oxygen in the mixture ullage dilutes the nitrous oxide vapor, and increases the required decomposition activation energy of the fluid by several orders of magnitude. Data from tests using each oxidizer are analyzed and presented for performance comparisons. Comparisons include, ignition reliability, ignition energy, thrust coefficient, characteristic velocity, specific impulse, and regression rate. Nytrox is shown to work effectively as a “drop in” replacement for gaseous oxygen, exhibiting slightly reduced specific impulse and regression rate, but with the trade of a significantly higher volumetric efficiency.
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Natarajan, Vinod K. (Vinod Kumar) 1979. "The performance of IC engine and fuel cell hybrid propulsion systems in light duty vehicles." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/89878.
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Sergent, Aaronn. "Optimal Sizing and Control of Battery Energy Storage Systems for Hybrid-Electric, Distributed-Propulsion Regional Aircraft." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1595519141013663.
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Bartlett, Brandon. "Simulation of a Configurable Hybrid Aircraft." DigitalCommons@CalPoly, 2021. https://digitalcommons.calpoly.edu/theses/2318.
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As the demand for air transportation is projected to increase, the environmental impacts produced by air travel will also increase. In order to counter the environmental impacts while also meeting the demand for air travel, there are goals and research initiatives that aim to develop more efficient aircraft. An emerging technology that supports these goals is the application of hybrid propulsion to aircraft, but there is a challenge in effectively exploring the performance of hybrid aircraft due to the time and money required for safe flight testing and due to the diverse design space of hybrid architectures and components. Therefore, computational tools that are capable of simulating the performance of a hybrid aircraft are incredibly useful in the design process and research space.
Existing work on the simulation of hybrid aircraft focuses on modelling a specific hybrid propulsion system in a particular airframe, but it would be desirable to have a simulation tool that is not specific to one design. In this thesis, a simulation framework that can be easily configured for different types of hybrid structures and components is presented, and the simulator is validated using flight test data which demonstrates that the performance of the simulated aircraft is representative of a real aircraft. A design for a hybrid aircraft is also modelled and simulated over different flight profiles in order to study the performance of the hybrid propulsion system. Results indicate that the hybrid aircraft can be successfully simulated and demonstrate how the simulator can be used as a tool to study the best way to fly and operate a hybrid aircraft.
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Schömann, Joachim [Verfasser], Mirko [Akademischer Betreuer] Hornung, and Horst [Akademischer Betreuer] Baier. "Hybrid-electric propulsion systems for small unmanned aircraft / Joachim Schömann. Gutachter: Mirko Hornung ; Horst Baier. Betreuer: Mirko Hornung." München : Universitätsbibliothek der TU München, 2014. http://d-nb.info/1063724023/34.
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Kaloun, Adham. "Conception de chaînes de traction hybrides et électriques par optimisation sur cycles routiers." Thesis, Ecole centrale de Lille, 2020. http://www.theses.fr/2020ECLI0019.
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La conception des chaînes de traction hybrides est une tâche complexe, qui fait appel à des experts de différents domaines s'appuyant sur des compétences et des outils distincts. En plus de cela, la recherche d'une solution optimale nécessite un retour système. Cela peut être, selon la granularité des modèles de composants, très coûteux en temps de calcul. Ceci est d'autant plus vrai lorsque la performance du système est déterminée par sa commande, comme c'est le cas du véhicule hybride. En fait, différentes possibilités peuvent être sélectionnées pour fournir le couple requis aux roues pendant le cycle de conduite. Ainsi, le principal obstacle est d'atteindre l'optimalité tout en conservant une méthodologie rapide et robuste. Dans ces travaux de thèse, de nouvelles approches visant à exploiter le potentiel complet de l'hybridation sont proposées et comparées. La première stratégie est une approche bi-niveaux composée de deux blocs d'optimisation imbriqués: un processus d'optimisation des paramètres de design externe qui calcule la meilleure valeur de consommation de carburant à chaque itération en se basant sur une version améliorée de la programmation dynamique pour l'optimisation de la commande. Deux stratégies de conception systémique différentes basées sur le schéma itératif sont également proposées. La première approche est basée sur la réduction de modèle tandis que la seconde se repose sur des techniques précises de réduction de cycle. Cette dernière permet l'utilisation de modèles de haute précision sans pénaliser le temps de calcul. Une approche simultanée est ensuite mise en œuvre, qui optimise à la fois les variables de conception et les paramètres d'une nouvelle stratégie efficace à base de règles. Cette dernière permettra une optimisation plus rapide par rapport à l'optimisation directe de toutes les variables de décision. Enfin, une technique basée sur l'utilisation des méta-modèles est explorée<br>Designing hybrid powertrains is a complex task, which calls for experts from various fields. In addition to this, finding the optimal solution requires a system overview. This can be, depending on the granularity of the models at the component level, highly time-consuming. This is even more true when the system’s performance is determined by its control, as it is the case of the hybrid powertrain. In fact, various possibilities can be selected to deliver the required torque to the wheels during the driving cycle. Hence, the main obstacle is to achieve optimality while keeping the methodology fast and robust. In this work, novel approaches to exploit the full potential of hybridization are proposed and compared. The first strategy is a bi-level approach consisting of two nested optimization blocks: an external design optimization process that calculates the best fuel consumption value at each iteration, found through control optimization using an improved version of dynamic programming. Two different systemic design strategies based on the iterative scheme are proposed as well. The first approach is based on model reduction while the second approach relies on precise cycle reduction techniques. The latter enables the use of high precision models without penalizing the calculation time. A co-optimization approach is implemented afterwards which adjusts both the design variables and parameters of a new efficient rule-based strategy. This allows for faster optimization as opposed to an all-at-once approach. Finally, a meta-model based technique is explored
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Nelson, Lauren May. "Rayleigh Flow of Two-Phase Nitrous Oxide as a Hybrid Rocket Nozzle Coolant." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/284.
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The Mechanical Engineering Department at California Polytechnic State University in San Luis Obispo currently maintains a lab-scale hybrid rocket motor for which nitrous oxide is utilized as the oxidizer in the combustion system. Because of its availability, the same two-phase (gas and liquid) nitrous oxide that is used in the combustion system is also routed around the throat of the hybrid rocket’s converging-diverging nozzle as a coolant. While this coolant system has proven effective empirically in previous tests, the physics behind the flow of the two-phase mixture is largely unexplained. This thesis provides a method for predicting some of its behavior by modeling it using the classic gas dynamics scenarios of Rayleigh and Fanno flows which refer to one-dimensional, compressible, inviscid flow in a constant area duct with heat addition and friction. The two-phase model produced utilizes a separated phase with interface exchange model for predicting whether or not dryout occurs. The Shah correlation is used to predict heat transfer coefficients in the nucleate boiling regime. The homogeneous flow model is utilized to predict pressure drop. It is proposed that a Dittus-Boelter based correlation much like that of Groeneveld be developed for modeling heat transfer coefficients upon the collection of sufficient data.
Data was collected from a series of tests on the hybrid rocket nozzle to validate this model. The tests were first run for the simplified case of an ideal gas (helium) coolant to verify the experimental setup and promote confidence in subsequent two-phase experimental results. The results of these tests showed good agreement with a combined Rayleigh-Fanno model with a few exceptions including: (1) reduced experimental gas pressure and temperature in the annulus entrance and exit regions compared to the model and (2) reduced experimentally measured copper temperatures uniformly through the annulus. These discrepancies are likely explained by the geometry of the flowpath and location of the copper thermocouples respectively. Next, a series of two-phase cooled experiments were run. Similar trends were seen to the helium experiment with regards to entrance and exit regions. The two-phase Rayleigh homogeneous flow model underpredicted pressure drop presumably due to the inviscid assumption. Ambiguity was observed in the fluid temperature measurements but the trend seemed to suggest that mild thermal non-equilibrium existed. In both cases, the dryout model predicted that mist flow (a post-CHF regime) occurred over most of the annulus.
Several modifications should be implemented in future endeavors. These include: (1) collecting more data to produce a heat transfer coefficient correlation specific to the nitrous oxide system of interest, (2) accounting for thermal non-equilibrium, (3) accounting for entrance and exit effects, and (4) developing a two-phase Fanno model.
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Ali, Ahmed Mohammed [Verfasser], and Dirk [Akademischer Betreuer] Söffker. "Design of Hybrid Propulsion Systems for Vehicles Considering Optimal Power Management and Control in Real-Time / Ahmed M. Ali ; Betreuer: Dirk Söffker." Duisburg, 2019. http://d-nb.info/1196008132/34.
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Wortmann, Guido [Verfasser], Mirko [Akademischer Betreuer] [Gutachter] Hornung, and Florian [Gutachter] Holzapfel. "Investigating the Dynamic Response of Hybrid-Electric Propulsion Systems for Flight Control Application / Guido Wortmann ; Gutachter: Mirko Hornung, Florian Holzapfel ; Betreuer: Mirko Hornung." München : Universitätsbibliothek der TU München, 2016. http://d-nb.info/1120013763/34.
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Liang, Jia-Yuan. "Design and Development of Propulsion System for Hybrid Electric Vehicles." 2007. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-2709200717363600.
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Liu, Yu-Lin, and 劉育霖. "Development of the Quad Hybrid Rocket Engine Levitating Platform Propulsion System." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/jgd659.
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碩士<br>國立交通大學<br>機械工程系所<br>107<br>This research focuses on developing the propulsion system for the Quad Hybrid Rocket Engine Levitating Platform (4-HELP). The 4-HELP is designed to demonstrate and verify the feasibility of developing a levitating and flight platform using hybrid rocket technology. The overall system includes three major subsystems, which are propulsion, structure and avionics. The avionics system include guidance navigation and control, telecommunication and electrical power system. The hybrid rocket engine is applied for the 4-HELP propulsion due to its safety, storable, cost effective and throttling capability characteristics. The equipment of the hybrid rocket propulsion system can be divided into few parts, which are tanks, plumbing and combustion chambers. The nitrogen (N2) is used as the pressurant for pressurizing the 90 wt\% hydrogen peroxide (H2O2) solution used as the oxidizer into the engine to mix with the solid polypropylene (PP) used as the fuel for combustion.
The 4-HELP requires total thrust of 240 kgf with 30 s endurance at maximum mass flow rate of oxidizer, where four engines and six composite tanks of 10 L volume are equipped. Among them, two tanks containing pressurant and four tanks containing oxidizer in order to supply the four engines simultaneously. Therefore, each engine could be operate at the various range of thrust and chamber pressure with the maximum value of 60 kgf and 40 bar respectively. The combustion endurance of each engine is 30 s under the conditions of maximum thrust and maximum oxidizer mass flow rate. To test the performance, this engine is mounted on a thrust stand with load cell, pressure transducers, turbine flow meter, balance flow meter and thermocouple. During a typical flight test, the thrust produced by the engine is not directly obtainable. Therefore, the feedback value of oxidizer mass flow rate and chamber pressure are essential in evaluating the instantaneous performance of the combustion engine during the flight. The thrust is throttled by controlling the oxidizer mass flow rate into the combustion engine using a control valve, where the chamber pressure changes due to the pressure drop created by it.
First, the performances of the designed engine, including the oxidizer to fuel mass ratio, the relationship between oxidizer mass flux and solid fuel regression rate, and the stability of the combustion are investigated at full thrust via hot fire tests. At the state of full oxidizer flow rate, the thrust and chamber pressure of the engine reached 60 kgf and 40 bar respectively as designed and the endurance is able to reach 30 s as required. After investigating the engine performances at full thrust and long combustion duration, the throttling performances of the engine are investigated. The data obtained from the hot fire test results are analyzed, where the chamber pressure and the thrust are found to be proportional to the oxidizer mass flow rate. These results verified that the hybrid rocket engines are capable of throttling simply by controlling the mass flow rate of oxidizer into the combustion chamber.
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Zhu, Haijia. "Modelling, design and energy management of a hybrid electric ship – a case study." Thesis, 2020. http://hdl.handle.net/1828/11726.
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The widely-used passenger and car ferries, sailing regularly and carrying heavy loads, form a unique type of marine vessel, providing vital transportation links to the coastal regions. Modern ferry ships usually are equipped with multiple diesel engines as prime movers. These diesel engines consume a large amount of marine diesel fuel with high fuel costs, and high emissions of greenhouse gas (GHG) and other harmful air pollutants, including CO2, HC, NOx, SO2, CO, and PM. To reduce fuel costs and the harmful emissions, the marine industry and ferry service providers have been seeking clean ship propulsion solutions.
In this work, the model-based design (MBD) and optimization methodology for developing advanced electrified vehicles (EV) are applied to the modelling, design and control optimizations of clean marine vessels with a hybrid electric propulsion system. The research focuses on the design and optimization of the hybrid electric ship propulsion system and uses an open deck passenger and car ferry, the MV Tachek, operated by the British Columbia Ferry Services Inc. Canada, as a test case. At present, the ferry runs on the Quadra Island – Cortes Island route in British Columbia, Canada, with dynamically changing ocean conditions in different seasons over a year.
The research first introduces the ship operation profile, using statistical ferry operation data collected from the ferry’s voyage data recorder and a data acquisition system that is specially designed and installed in this research. The ship operation profile model with ship power demand, travelling velocity and sailing route then serves as the design and control requirements of the hybrid electric marine propulsion system. The development of optimal power control and energy management strategies and the optimization of the powertrain architecture and key powertrain component sizes of the ship propulsion system are then carried out. Both of the series and parallel hybrid electric propulsion architectures have been studied. The sizes of crucial powertrain components, including the diesel engine and battery energy storage system (ESS), are optimized to achieve the best system energy efficiency. The optimal power control and energy management strategies are optimized using dynamic programming (DP) over a complete ferry sailing trip.
The predicted energy efficiency and emission reduction improvements of the proposed new ship with the optimized hybrid propulsion system are compared with those of two benchmark vessels to demonstrate the benefits of the new design methodology and the optimized hybrid electric ship propulsion system design. These two benchmarks include a conventional ferry with the old diesel-mechanical propulsion system, and the Power Take In (PTI) hybrid electric propulsion systems installed on the MV Tachek at present. The simulation results using the integrated ship propulsion system model showed that the newly proposed hybrid electric ship could have 17.41% fuel saving over the conventional diesel-mechanical ship, and 22.98% fuel saving over the present MV Tachek. The proposed optimized hybrid electric propulsion system, combining the advantages of diesel-electric, pure electric, and mechanical propulsions, presented considerably improved energy efficiency and emissions reduction. The research forms the foundation for future hybrid electric ferry design and development.<br>Graduate
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Yen, Liang-Hsi, and 顏良喜. "Eenergy economy torque distribution strategy for an intelligent plug-in hybrid propulsion system." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/50087640314843548550.
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碩士<br>國立臺灣大學<br>機械工程學研究所<br>104<br>This thesis aims at developing a torque distribution strategy for an intelligent plug-in hybrid electric vehicles using Telematics. This research proposes two different kinds of control structure. The fisrt one is similar to traditional torque distribution strategies, it focuses on finding the optimum split ration of the powertrain system, the proposed control strategy combines two different control strategies, and make use of Telematics to futher improve the performance. The simulation shows that the result of proposed control strategy is very close to that of a global optimum method, and is 15%~20% better than other control strategies. The second structure is dictinct from normal torque distriburion strategy, it replaces the driver model with an optimum speed controller. The function of the optimum speed controller is to find a speed profile according to the status of car and information provided by Telematics, the goal is to make the system operates at its highest efficiency zone. The result shows that the optimum speed controller will futher improve 5%~10% of the perforamce.
The proposed control strategies are tested in model in the loop simulation, simulation environment is established based on experimental data to ensure the verisimilitude of the simulations. The propsed control strategies are futher compiled to a real time environment to verify the feasibility of implementing in real car systems.
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Liu, Siyang. "Model-based design of hybrid electric marine propulsion system using modified low-order ship hull resistance and propeller thrust models." Thesis, 2020. http://hdl.handle.net/1828/12518.
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Transportation is a primary pollution source contributing to 14 percent of global greenhouse gas emissions, and 12 percent of transportation emissions came from maritime activities. Emissions from the ferry industry, which carries roughly 2.1 billion passengers and 250 million vehicles annually, is a major concern for the general public due to their near-shore operations. Compared to the rapidly advancing clean automotive propulsion, fuel efficiency and emissions improvements for marine vessels are more urgent and beneficial due to the significantly higher petroleum fuel consumption and heavy pollutants and the relatively slow adoption of clean propulsion technology by the marine industry. Hybrid electric propulsion, proven to be effective for ground vehicles, presents a promising solution for more efficient clean marine transportation. Due to the diversified hull/propulsor design and operation cycle, the development of a hybrid electric marine propulsion system demands model-based design and control optimization for each unique and small batch production vessel. The integrated design and control optimization further require accurate and computation efficient hull resistance and propulsor thrust calculation methods that can be used to predict needed propulsion power and gauge vessel performance, energy efficiency, and emissions. This research focuses on improving the low-order empirical hull resistance and propulsor thrust models in the longitudinal direction by extracting model parameters from one-pass computational fluid dynamics (CFD) simulation and testing the acquired models in integrated design optimization of the marine propulsion system. The model is implemented in MATLAB/Simulink and ANSYS Aqwa and validated using operation data from BC Ferries’ ship Tachek. The modified low-order model (M-LOM) is then used in the integrated optimizations of propulsion system component sizes and operation control strategies for another BC Ferries’ ship, Skeena Queen. The performance, energy efficiency, and emissions of various propulsion options, including nature gas-mechanical and natural gas-electric benchmarks, and hybrid electric alternatives of series hybrid, parallel hybrid, and battery/pure electric are compared to demonstrate the benefits of the new method in completing these complex tasks and hybrid electric marine propulsion. The research forms the foundation for further studies to achieve more accurate propulsion demand prediction and a more comprehensive lifecycle cost assessment of clean marine propulsion solutions.<br>Graduate
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Chou, Tzu-Hao, and 周子豪. "Numerical and Experimental Investigation of Single-Port Hybrid Rocket Propulsion System with Nitrous Oxide and Hydroxyl-terminated Polybutadiene (HTPB) using Mixing Enhancer(s)." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/28dagq.
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博士<br>國立交通大學<br>機械工程系所<br>103<br>Recently, hybrid rocket propulsion has attracted much attention because of many advantages, including high safety, high performance and low cost. Hybrid rocket system has better propulsion performance as compared to solid rocket system, but combustion efficiency of diffusion flame is generally low because of poor mixing between fuel and oxidizer. Thus, how to improve the mixing efficiency between fuel and oxidizer while keeping the simplicity of the system is one of the major research topics in hybrid propulsion. In this thesis, mixing enhancers are proposed to improve mixing efficiency between fuel and oxidizer in a single-port combustor and are investigated in detail both numerically and experimentally.
In the numerical part, a parallel computational fluid dynamic solver using unstructured grids was used to simulate both the cold flow and reacting flow in a hybrid combustion chamber. In the cold flow study, a series of parametric study, including variations of blade number, angle of attack, span, and chord length, was performed to investigate their influence on the axial vorticity generated in the port. The results show that the highest axial vorticity can be generated using a configuration of mixing enhancers consisting of 8 blades, 23.5 degrees of angle of attack, 6 mm of span length, and 15 mm of chord length. In the reacting flow study, by using one and two stages of mixing enhancers, an appreciable improvement of combustion efficiency, up to 14% (vacuum Isp: 235 s) and 24% (vacuum Isp: 255 s), respectively, as compared to the case without mixing enhancer in a single-port hybrid combustor was demonstrated with a thrust level of 300 kgf. Corresponding O/F ratio ranges from 10.87 to 7.21, which is a typical fuel-lean combustion. Through the simulated temperature distributions in the chamber, several important features of mixing caused by the use of the mixing enhancers are clarified and explained. In the scale-up study based on geometric amplification concept (e.g., 1.87 from 300 kgf to 1,000 kgf level), we have found that the reduction of the fuel grain axial length, as compared to the standard amplification, downgrades the combustion efficiency. This leads us to conclude that even with two stages of mixing enhancers we still need enough port length for the fuel and oxidizer to mix more thoroughly for a better combustion. Similarly, increase of port diameter also leads to deteriorated performance caused by the relatively poor mixing.
In the experimental part, we have performed several key static-burn tests for a single-port combustor design with various stages of mixing enhancers, which include different levels of thrust considering the scale-up effect (50 kgf, 100 kgf, 300 kgf, and 1,000 kgf). In the test of 100 kgf level of combustor, the results showed 30% increase of vacuum Isp (up to 219 sec) with one stage of mixing enhancer, which coincides with the findings of the numerical simulations. Based on this finding, we have performed several tests for the 300 kgf level. The results with two stages of mixing enhancers showed an impressive vacuum Isp of 236 s, which is better than most of the solid propulsion systems. The motors with one and two stages of mixing enhancers have been employed successfully in the flight tests of HTTP-1 and HTTP-2beta in 2010 and 2013 respectively. In the tests of 1000 kgf level, we have changed the N2O flow rate which were used to test the performance of thrust throttling caused by changes of the flow rate and possibly the O/F shift issue. In addition, we have also observed uneven burned port surfaces of HTPB which correlates well with the simulated temperature distribution. In order to obtain more reliable experimental data, we redesign the 50 kgf chamber for pure experiment purpose, which leads to further confirmation of the benefits of using mixing enhancer.
Major findings and recommendations of future work are summarized at the end of thesis.
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Predut, S., F. Ipate, Marian Gheorghe, and I. Felician Campean. "Formal Modelling of Cruise Control System Using Event-B and Rodin Platform." 2018. http://hdl.handle.net/10454/16555.
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no<br>Formal modelling is essential for precisely defining, understanding and reasoning when designing complex systems, such as cyberphysical systems. In this paper we present a formal specification using Event-B and Rodin platform for a case study of a cruise control system for a hybrid propulsion vehicle and electric bicycle (e-Bike). Our work uses the EventB method, a formal approach for reliable systems specification and verification, being supported by the Rodin platform, based on theorem proving, allowing a stepwise specification process based on refinement. We also use, from the same platform, the ProB model checker for the verification of the B-Machine and iUML plug-in to visualize our model. This approach shows the benefits of using a formal modelling platform, in the context of cyberphysical systems, which provides multiple ways of analysing a system.<br>Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-III-P4-ID-PCE-20160210.
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Matlock, Jay Michael Todd. "Evaluation of hybrid-electric propulsion systems for unmanned aerial vehicles." Thesis, 2019. http://hdl.handle.net/1828/11484.
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The future of aviation technology is transitioning to cleaner, more efficient and higher endurance aircraft solutions. As fully electric propulsion systems still fall short of the operational requirements of modern day aircraft, there is increasing pressure and demand for the aviation industry to explore alternatives to fossil fuel driven propulsion systems. The primary focus of this research is to experimentally evaluate hybrid electric propulsion systems (HEPS) for Unmanned Aerial Vehicles (UAV) which combine multiple power sources to improve performance. HEPS offer several potential benefits over more conventional propulsion systems such as a smaller environmental impact, lower fuel consumption, higher endurance and novel configurations through distributed propulsion. Advanced operating modes are also possible with HEPS, increasing the vehicle’s versatility and redundancy in case of power source failure.
The primary objective of the research is to combine all of the components of a small-scale HEPS together in a modular test bench for evaluation. The test bench uses components sized for a small-scale UAV including a 2.34kW two-stroke 35cc engine and a 1.65kW brushless DC motor together with an ESC capable of regenerative braking. Individual components were first tested to characterize performance, and then all components were assembled together in a parallel configuration to observe system-level performance. The parallel HEPS is capable of functioning in the four required operating modes: EM Only, ICE Only, Dash Mode (combined EM and ICE power) as well as Regenerative Mode where the onboard batteries get recharged. Further, the test bench was implemented with a supervisory controller to optimize system performance and run each component in the most efficient region to achieve torque requirements programmed into mission profiles. The logic based controller operates with the ideal operating line (IOL) concept and is implemented with a custom LabView GUI.
The system is able to run on electric power or ICE power interchangeably without making any modifications to the transmission as the one-way bearing assembly engages for whichever power source is rotating at the highest speed. The most impressive of these sets of tests is the Dash mode testing where the output torque of the propeller is supplied from both the EM and ICE. Working in tandem, it was proved that the EM was drawing 19.9A of current which corresponds to an estimated 0.57Nm additional torque to the propeller for a degree of hybridization of 49.91%. Finally, the regenerative braking mode was proven to be operational, capable of recharging the battery systems at 13A. All of these operating modes attest to the flexibility and convenience of having a hybrid-electric propulsion system.
The results collected from the test bench were validated against the models created in the aircraft simulation framework. This framework was created in MATLAB to simulate the performance of a small UAV and compare the performance by swapping in various propulsion systems. The purpose of the framework is to make direct comparisons of HEPS performance for parallel and series architectures against conventional electric and gasoline configuration UAVs, and explore the trade-offs. Each aircraft variable in the framework was modelled parametrically so that parameter sweeps could be run to observe the impact on the aircraft’s performance. Finally, rather than comparing propulsion systems in steady-state, complex mission profiles were created that simulate real life applications for UAVs. With these experiments, it was possible to observe which propulsion configurations were best suited for each mission type, and provide engineers with information about the trade-offs or advantages of integrating hybrid-electric propulsion into UAV design.
In the Pipeline Inspection mission, the exact payload capacities of each aircraft configuration could be observed in the fuel burn versus CL,cruise parameter sweep exercise. It was observed that the parallel HEPS configuration has an average of 3.52kg lower payload capacity for the 35kg aircraft (17.6%), but has a fuel consumption reduction of up to 26.1% compared to the gasoline aircraft configuration. In the LIDAR Data collection mission, the electric configuration could be suitable for collection ranges below 100km but suffers low LIDAR collection times. However, at 100km LIDAR collection range, the series HEPS has an endurance of 16hr and the parallel configuration has an endurance of 19hr. In the Interceptor mission, at 32kg TOW, the parallel HEPS configuration has an endurance/TOW of 1.3[hr/kg] compared to 1.15[hr/kg] for the gasoline aircraft. This result yields a 13% increase in endurance from 36.8hr for gasoline to 41.6hr for the parallel HEPS. Finally, in the Communications Relay mission, the gasoline configuration is recommended for all TOW above 28kg as it has the highest loiter endurance.<br>Graduate
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Andersen, Kevin. "Development of a time-domain modeling platform for hybrid marine propulsion systems." Thesis, 2016. http://hdl.handle.net/1828/7245.
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This thesis develops a time-domain integrated modeling approach for design of hybrid-electric marine propulsion systems that enables co-simulation of powertrain dynamics along with ship hydrodynamics. This work illustrates the model-based design and analysis methodology by performing a case study for an EV conversion of a short-cross ferry using the BC Ferries’ M.V. Klitsa. A data acquisition study was performed to establish the typical mission cycle of the ship for its crossing route between Brentwood Bay and Mill Bay, across the Saanich Inlet near Victoria, BC Canada. The data provided by the data acquisition study serves as the primary means of validation for the model’s ability to accurately predict powertrain loads over the vessel’s standard crossing. This functionality enables model-based powertrain and propulsion system design optimization through simulation to intelligently deploy hybrid-electric propulsion architectures.
The ship dynamics model is developed using a Newton-Euler approach which incorporates hydrodynamic coefficient data produced by potential flow solvers. The radiation forces resulting from vessel motion are fit to continuous time-domain transfer functions for computational efficiency. The ship resistance drag matrix is parameterized using results from uRANS CFD studies that span the operating range of the vessel. A model of the existing well-mounted azimuthing propeller is developed to predict thrust production and mechanical torque for pseudo-second quadrant operation to represent all operating conditions seen in real operation. The propeller model is parameterized from the results of a series of uRANS CFD on the propeller geometry. A full battery-electric powertrain model is produced to study the accuracy of the model in predicting the drivetrain loads, as well as assessing the technological feasibility of an EV conversion for this particular vessel. A dual-polarization equivalent circuit model is created for a large-scale LTO battery pack. An average value model with MTPA control and dynamics loss model is developed for a commercially available electric drive system. Power loss models were developed for required converter topologies for computational efficiency. The model results for load prediction are compared to data acquired, and results indicate that the approach is effective for enabling the study of various powertrain architecture alternatives.<br>Graduate