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1
Westin, Fredrik. "Accuracy of turbocharged SI-engine simulations." Licentiate thesis, KTH, Machine Design, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1491.
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This licentiate thesis deals mainly with modelling ofturbocharged SIengines. A model of a 4-cylinder engine was runin both steady state and transient conditions and the resultswere compared to measured data. Large differences betweenmeasurements and simulations were detected and the reasons forthis discrepancy were investigated. The investigation showedthat it was the turbocharger turbine model that performed in anon-optimal way. To cope with this, the turbine model containedparameters, which could be adjusted so that the model resultsmatched measured data. However, it was absolutely necessary tohave measured data to match against. It was thus concluded thatthe predictivity of the software tool was too poor to try topredict the performance of various boosting systems. Thereforemeans of improving the modelling procedure were investigated.To enable such an investigation a technique was developed tomeasure the instantaneous power output from, and efficiency of,the turbine when the turbocharger was used on the engine.
The projects initial aim was to predict, throughsimulations, the best way to boost a downsized SI-engine with avery high boost-pressure demand. The first simulation run on astandard turbocharged engine showed that this could not be donewith any high accuracy. However, a literature study was madethat presents various different boosting techniques that canproduce higher boost pressure in a larger flow-range than asingle turbocharger, and in addition, with smallerboost-pressure lag.
Key words:boosting, turbocharging, supercharging,modelling, simulation, turbine, pulsating flow, unsteadyperformance, SI-engine, measurement accuracy
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Kristoffersson, Ida. "Model Predictive Control of a Turbocharged Engine." Thesis, KTH, Reglerteknik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-107508.
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Engine control becomes increasingly important in newer cars. It is therefore interesting to investigate if a relatively new control method as Model Predictive Control (MPC) can be useful in engine control in the future. One of the advantages of MPC is that it can handle contraints explicitly. In this thesis basics on turbocharged engines and the underlying theory of MPC is presented. Based on a nonlinear mean value engine model, linearized at multiple operating points, we then implement both a linear and a nonlinearMPC strategy and highlight implementation issues. The implemented MPC controllers calculate optimal wastegate position in order to track a requested torque curve and still make sure that the constraints on turbocharger speed and minimum and maximum opening of the wastegate are fulfilled.
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Jo, Young Suk. "Turbocharged engine operations using knock resistant fuel blends for engine efficiency improvements." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81606.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 61).
Engine downsizing with a turbocharger has become popular these days in automotive industries. Downsizing the engine lets the engine operate in a more efficient region, and the engine boosting compensates for the power loss accompanied by downsizing. However, the use of high boost in a downsized engine is limited by knock. Changing operating parameters such as spark timing has shown to be effective in avoiding knock. However, those strategies usually deteriorate efficiency of the engine. Another method to suppress knock without lowering efficiency is to use knock resistant fuels. Among them ethanol has gotten a large attention due to its renewable characteristics. About 13.3 billion gallons of ethanol were produced in 2012, and about 99 % of them are used as fuel added to gasoline. However, the optimal use of ethanol in a spark ignited engine as a knock suppressing additive is not well quantified. Also, operation limitations of a knock free engine are not well known. The objective of this project was to determine the knock onset engine operating conditions and to explore the potential of a direct injection of ethanol enhanced fuels. An engine with a turbocharger was used to measure efficiencies of the engine over the wide range of operating points. Speed range was chosen from 1500 rpm to 3000 rpm in which vehicle is usually driven in the driving cycle. Then, knock onset of different ethanol-gasoline blends, from 0 % ethanol to 85 % ethanol contents with 91 RON gasoline, were determined. Generated engine fuel consumption maps with knock onset limits were utilized in a vehicle driving simulation tool. In a simulation, the consumption of gasoline and knock suppressing fuels was determined in different driving cycles. Finally, effects of downsizig and spark retard on ethanol fraction in the fuel were determined.
by Young Suk Jo.
S.M.
4
Renberg, Ulrica. "1D engine simulation of a turbocharged SI engine with CFD computation on components." Licentiate thesis, KTH, Machine Design (Div.), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9162.
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1D engine simulations of turbocharged engines are difficult to
Techniques that can increase the SI- engine efficiency while keeping the emissions very low is to reduce the engine displacement volume combined with a charging system. Advanced systems are needed for an effective boosting of the engine and today 1D engine simulation tools are often used for their optimization.
This thesis concerns 1D engine simulation of a turbocharged SI engine and the introduction of CFD computations on components as a way to assess inaccuracies in the 1D model.
1D engine simulations have been performed on a turbocharged SI engine and the results have been validated by on-engine measurements in test cell. The operating points considered have been in the engine’s low speed and load region, with the turbocharger’s waste-gate closed.
The instantaneous on-engine turbine efficiency was calculated for two different turbochargers based on high frequency measurements in test cell. Unfortunately the instantaneous mass flow rates and temperatures directly upstream and downstream of the turbine could not be measured and simulated values from the calibrated engine model were used. The on-engine turbine efficiency was compared with the efficiency computed by the 1D code using steady flow data to describe the turbine performance.
The results show that the on-engine turbine efficiency shows a hysteretic effect over the exhaust pulse so that the discrepancy between measured and quasi-steady values increases for decreasing mass flow rate after a pulse peak.
Flow modeling in pipe geometries that can be representative to those of an exhaust manifold, single bent pipes and double bent pipes and also the outer runners of an exhaust manifold, have been computed in both 1D and 3D under steady and pulsating flow conditions. The results have been compared in terms of pressure losses.
The results show that calculated pressure gradient for a straight pipe under steady flow is similar using either 1D or 3D computations. The calculated pressure drop over a bend is clearly higher1D engine simulations of turbocharged engines are difficult to using 1D computations compared to 3D computations, both for steady and pulsating flow. Also, the slow decay of the secondary flow structure that develops over a bend, gives a higher pressure gradient in the 3D calculations compared to the 1D calculation in the straight pipe parts downstream of a bend.
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Chan, Siew Hwa. "Transient performance of turbocharged vehicle diesel engines." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/46707.
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Rezaeian, M. "Modelling of engine transmission systems for heavy vehicles : the differential compound engine versus the turbocharged engine." Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484306.
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Roberts, Stefan Ross. "Non-intrusive knock detection in a turbocharged, dual fuel engine." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq22664.pdf.
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Ren, Zizhong. "Theoretical and experimental study on sequentially turbocharged diesel engine performance." Thesis, Glasgow Caledonian University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388308.
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An investigation on the sequential turbocharging of a Kelvin TFSC6 6-cylinder 4- stroke marine diesel engine developing 320 kW at 1200 r/min is reported in this thesis. The sequential turbocharging (ST) system, utilising turbochargers of unequal size, resulted in significant improvement when compared with previously designed systems. The engine test results show that the new sequential turbocharging system improves the engine performance at both high speeds and low speeds except at or near to the 'transfer' speed. The engine low speed performance is obviously improved with the fuel saving of up to 7 g/kwh for the 1st sequence. The engine high speed performance is also improved for the 2nd sequence where both turbochargers are in operation. There is some boost air leakage from the delivery pipe which is used for connecting the peak unit to the intercooler inlet. This restricts the 2nd sequence gains. An optimised sequence transfer control mode is also proposed in this research and validated by both test and simulation results. Two control valves, one at the peak unit turbine inlet and the other at the compressor outlet, are specifically designed for the ST system and both of them worked very well during the engine test programme. Both simulation models - "Filling& Emptying" and "Method of Characteristic" were modified and used for the sequential turbocharging simulation. The modified program of the "Filling& Emptying" model can be used to analyse and compare the effects of different exhaust systems. It can also be applied to simulate and design a pulse converter system for a sequential turbocharged diesel engine. The modification on the "MOC" program makes it possible to simulate the exhaust pressure wave for the ST system with different turbocharger arrangements (concentrated or separated). The consideration of pressure losses in the 'three branch junction' boundary improves the simulation accuracy. In addition, a comprehensive engine test data acquisition and control system has been developed in this study. The advanced system with many new features can be used for engine condition monitoring. diagnosis and other similar applications for engine development and test. The efficiency and reliability of the system have been corroborated by the engine test process. The real time data process, analysis and display in various forms are available using the developed program with 'LabVIEW'. The proposed self-adaptive auto-load setting with optimised parameters is validated as an economic solution for engine load control with an early type of hydraulic dynamometer.
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McCoy, Colleen (Colleen M. ). "Fuel economy of a turbocharged, single-cylinder, four-stroke engine." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112556.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 56-57).
Agriculture is the main source of livelihood for a majority of India's population. However, despite the number of workers, the yield and the yield of principal crops in India is much lower than that in developed nations. One of the reasons for this is the lack of farming mechanization in India. One of the common ways to run farming equipment is by using a single-cylinder, four-stroke diesel engine. Diesel engines can be turbocharged in order to make them more efficient for less cost. A method has been found to turbocharge a single-cylinder diesel engine by adding an air capacitor to form a buffer between the intake and exhaust strokes. This thesis analyzes how the size and heat transfer of the air capacitor for this turbocharged diesel engine are correlated to engine performance and fuel economy. According to the modeled engine, a 3.0 liter capacitor had better peak power and fuel economy at high loads and speeds than a 2.4 or 1.25 liter capacitor. Additionally, forced convection cooling on the capacitor using a fan allowed the intake air density to increase, and the engine to have better fuel economy than the . However the peak power and fuel economy of the modeled naturally aspirated engine was better than the turbocharged engine for speeds below 2500 rpm. The general trends from the model were reflected in the experimental data. The forced convection increased cooling, and improved the intake air density. However, it was difficult to make any confident recommendations about the fuel economy based on the experimental data.
by Colleen McCoy.
S.B.
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Ghazy, Mohamed Riad Aly. "Exciting forces and their relationship to turbocharged diesel engine vibration." Thesis, University of Southampton, 1986. https://eprints.soton.ac.uk/52293/.
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The work presented here quantifies the forces applied to the main bearings of three six-cylinder turbocharged diesel engines and reviews their exciting properties in both time and frequency domains. The engine structure response at the bearing supports and the outer surfaces are correlated. Vibration acceleration was measured, in the three different directions, at the engine main bearings and the outer surface. The liner vibrations were also measured. A theoretical model for calculating the bearing forces and estimating the bearing moment characteristics is proposed. The calculated bearing forces are investigated in both time and frequency domains. The characteristics of the forces driving the piston across the cylinder clearance are calculated. The characteristics of the forces acting on the liner by the piston are also calculated. Combining the results of the measurements with the theoretical model for force calculation, a technique for estimating the actual running clearance of the piston is presented. A technique for deriving the displacement from the measured acceleration is developed. By representing the engine response in terms of displacement it is possible to recognise the applied force time history and thus the identification of the specific parts of the engine structure primarily excited by moments and by direct force. It is shown that the engine structure response is a transient phenomenon and is maximum in the vicinity of the applied force. The displacement technique for quantifying engine response provides detailed information of the distortion of the running engine enabling the prediction of mechanical inputs which control the turbocharged engine noise.
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Raimbault, Vincent. "Benefit of air intake optimization for new turbocharged gasoline engine." Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0024.
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Ces dernières années les ventes de moteurs à allumage commandé sont croissantes. Pourtant les exigences en termes d’émissions de CO2 et d’émissions polluantes sont devenues plus contraignantes, taxant lourdement les dépassements. De plus le cycle d’homologation a évolué vers un élargissement de la fenêtre d’utilisation du moteur ou les émissions sont réglementées. La réduction de cylindrée « downsizing » opérée ces dernières années a permis de réduire les consommations notamment grâce à la réduction des pertes par pompage. Les performances ont pu être maintenues par l’adoption de système de suralimentation et notamment du turbocompresseur. Celui-ci présente toutefois une lacune à bas régime où il ne peut fournir une réponse instantanée et où la pression desuralimentation est limitée. De même à plus haut régime le fort taux de compression utilisé pour augmenter le rendement du moteur rend difficile le contrôle du cliquetis. Cette thèse s’est focalisée sur l’utilisation des ondes de pression pour améliorer la réponse du moteur à bas régime. Tout d’abord avec des outils de simulation puis en validation sur banc moteur. Une seconde partie a permis de développer une architecture de ligne d’admission d’air permettant de réduire la température d’admission afin d’augmenter la résistance au cliquetis et d’augmenter l’avance à l’allumage. La température d’échappement est ainsi réduite. Celle-ci est un élément dimensionnant de la stratégie moteur qui a maintenu, dans ces travaux, un mélange stoechiométrique afin de limiter les émissions polluantesThe last years have witnessed a strong increase of the sold spark ignition engines. Furthermore the new regulations are formally constraining pollutant emissions and CO2 with high fines. In the same time the new homologation driving cycle extends the engine operating conditions where the emissions need to be controlled. The downsizing has been a strong lever over the last years to improve the fuel consumption with reduction of the throttling and thus the pumping losses. With the downsizing, the turbocharger has been widely adopted to maintain the output performance. The implementation of turbocharger challenges the time to torque and the low end torque at low engine speed. In the same time the increase of boost pressure associated to high compression ratio confront the knock controls at maximum power operating conditions. This thesis focuses on acoustic boosting with volumetric efficiency enhancement to improve the low end torque and the time to torque. Firstly a simulation model allows taking into account the combustion behavior as well as the turbocharger characteristics. The intake geometry has been optimized to enhance the engine response time and low end torque. The second part deals with the pressure wave action used to reduce the intake temperature and thus improve the knock resistance being beneficial for exhaust gas temperature reduction. The interaction between the waves created the different cylinder is demonstrated. The test has confirmed the power increase while maintaining lambda 1 and thus keeping the three way catalyst efficient
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Baranski, Jacob A. "Experimental Investigation of Octane Requirement Relaxation in a Turbocharged Spark-Ignition Engine." University of Dayton / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1375262182.
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Cieslar, Dariusz. "Control for transient response of turbocharged engines." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/244951.
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The concepts of engine downsizing and down-speeding offer reductions in CO2 emissions from passenger cars. These reductions are achieved by reducing pumping and friction losses at part-load operation. Conventionally, rated torque and power for downsized units are recovered by means of turbocharging. The transient response of such engines is, however, affected by the static and dynamic characteristics of the turbo-machinery. Recent advances in engine simulation and control tools have been employed for the purpose of the research reported in this thesis to identify and verify possible air-path enhancements. A systematic method for evaluating various turbocharger assistance concepts is proposed and discussed in this thesis. To ensure a fair comparison of selected candidate systems, an easily reconfigurable controller providing a close-to-optimal operation, while satisfying physical limits, is formulated. This controller is based on the Model Predictive Control framework and uses a linearised mean value model to optimise the predicted behaviour of the engine. Initially, the controller was applied to a 1D simulation model of a conventional light-duty Diesel engine, for which the desired closed-loop features were verified. This procedure was subsequently applied to various air-path enhancement systems. In this thesis, a turbocharger electric assistance and various concepts based on compressed gas injection were considered. The capability of these systems to improve engine response during third gear tip-in manoeuvre was quantified. This investigation was also complemented with a parametric study of how effectively each of the considered methods used its available resources. As a result, injecting compressed gas into the exhaust manifold was identified as an effective method, which to date has attracted limited attention from engine research community. The effectiveness of the exhaust manifold assistance was experimentally verified on a light-duty Diesel engine. The sensitivity of the improvements to compressed gas supply parameters was also investigated. This led to the development of the BREES system: a low component count, compressed gas based system for reducing turbo-lag. It was shown that during braking manoeuvres a tank can be charged to the level sufficient for a subsequent boost assistance event. Such a functionality was implemented with a very limited set of additional components and only minor changes to the standard engine control.
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Argolini, Roberto, and Viviana Bloisi. "On optimal control of the wastegate in a turbocharged SI engine." Thesis, KTH, Reglerteknik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-106241.
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The project aims to improve positive torque transient response through more advanced wastegate controllers than what are used today. All controllers are developed for a standard General Motors turbocharged engine. In many turbocharged SI engines, a wastegate is used for preventing the turbine to overrun and to decrease the pumping loss. Today, the wastegate is controlled by a PI controller, which tries to fulfill a compromise between fuel consumption and torque response by regulating the wastegate position. A nonlinear Mean Value Engine Model (MVEM) of this engine, with 13 states and linearized in 45 different working points, is used. The original model, implemented in Matlab/Simulink, has been enriched with new features, like lambda and spark advance efficiencies and the related exhaust temperature correction. The project aims to do a theoretical analysis to find the optimal control of wastegate position, investigating also spark retard and fuel enrichment during a positive torque transient. First a solution for achieving optimal wastegate control is designed, based on Linear Quadratic (LQ) approach. Since the optimal control strategy is expected to vary quite much for different working points, a gain scheduling architecture has been investigated. An independent lambda controller has been developed, in order to maximize the lambda efficiency and quicken the torque response during transient. Since the system operates near a constraint boundary, another solution based on Model Predictive Control (MPC) of the wastegate has been investigated. The MPC design has been extended also to a MIMO formulation, adding the throttle and the air to fuel ratio as control inputs, and the trade off between fast torque response and fuel economy is analyzed. A complete realtime MPC implementation, with the capability for automatic code generation in the dSpace microAutobox environment, requires the model, now with 13 states, to be reduced to a minimum state space order. The extent of model reduction that is required and the possible performance deterioration have been investigated.
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Tuvesson, Stefan. "Tuning and Validation of an MVEM for a Turbocharged Gasoline Engine." Thesis, Linköping University, Linköping University, Vehicular Systems, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-16610.
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Aghaali, Habib. "On-Engine Turbocharger Performance Considering Heat Transfer." Licentiate thesis, KTH, Maskinkonstruktion (Inst.), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-93981.
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Heat transfer plays an important role in affecting an on-engine turbocharger performance. However, it is normally not taken into account for turbocharged engine simulations. Generally, an engine simulation based on one-dimensional gas dynamics uses turbocharger performance maps which are measured without quantifying and qualifying the heat transfer, regardless of the fact that they are measured on the hot-flow or cold-flow gas-stand. Since heat transfer situations vary for on-engine turbochargers, the maps have to be shifted and corrected in the 1-D engine simulation, which mass and efficiency multipliers usually do for both the turbine and the compressor. The multipliers change the maps and are often different for every load point. Particularly, the efficiency multiplier is different for every heat transfer situation on the turbocharger. The heat transfer leads to a deviation from turbocharger performance maps, and increased complexity of the turbocharged engine simulation. Turbochargers operate under different heat transfer situations while they are installed on the engines. The main objectives of this thesis are: heat transfer modeling of a turbocharger to quantify and qualify heat transfer mechanisms, improving turbocharged engine simulation by including heat transfer in the turbocharger, assessing the use of two different turbocharger performance maps concerning the heat transfer situation (cold-measured and hot-measured turbocharger performance maps) in the simulation of a measured turbocharged engine, prediction of turbocharger walls’ temperatures and their effects on the turbocharger performance on different heat transfer situations. Experimental investigation has been performed on a water-oil-cooled turbocharger, which was installed on a 2-liter GDI engine for different load points of the engine and different heat transfer situations on the turbocharger by using insulators, an extra cooling fan, radiation shields and water-cooling settings. In addition, several thermocouples have been used on accessible surfaces of the turbocharger to calculate external heat transfers. Based on the heat transfer analysis of the turbocharger, the internal heat transfer from the bearing housing to the compressor significantly affects the compressor. However, the internal heat transfer from the turbine to the bearing housing and the external heat transfer of the turbine housing mainly influence the turbine. The external heat transfers of the compressor housing and the bearing housing, and the frictional power do not play an important role in the heat transfer analysis of the turbocharger. The effect of the extra cooling fan on the energy balance of the turbocharger is significant. However, the effect of the water is more significant on the external heat transfer of the bearing housing and the internal heat transfer from the bearing housing to the compressor. It seems the radiation shield between the turbine and the compressor has no significant effect on the energy balance of the turbocharger. The present study shows that the heat transfer in the turbocharger is very crucial to take into account in the engine simulations. This improves simulation predictability in terms of getting the compressor efficiency multiplier equal to one and turbine efficiency multiplier closer to one, and achieving turbine outlet temperature close to the measurement. Moreover, the compressor outlet temperature becomes equal to the measurement without correcting the map. The heat transfer situation during the measurement of the turbocharger performance influences the amount of simulated heat flow to the compressor. The heat transfer situation may be defined by the turbine inlet temperature, oil heat flux and water heat flux. However, the heat transfer situation on the turbine makes a difference on the required turbine efficiency multiplier, rather than the amount of turbine heat flow. It seems the turbine heat flow is a stronger function of available energy into the turbine. Of great interest is the fact that different heat situations on the turbocharger do not considerably influence the pressure ratio of the compressor. The turbine and compressor efficiencies are the most important parameters that are affected by that. The component temperatures of the turbocharger influence the working fluid temperatures. Additionally, the turbocharger wall temperatures are predictable from the experiment. This prediction enables increased precision in engine simulations for future works in transient operations.QC 20120504
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Negrete, Justin E. "Effects of different fuels on a turbocharged, direct injection, spark ignition engine." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59952.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 65).
The following pages describe the experimentation and analysis of two different fuels in GM's high compression ratio, turbocharged direct injection (TDI) engine. The focus is on a burn rate analysis for the fuels - gasoline and E85 - at varying intake air temperatures. The results are aimed at aiding in a subsequent study that will look at the benefits of direct injection in turbocharged engines, ethanol's knock suppression properties, and the effects of ethanol concentration in gasoline/ethanol blends. Spark sweeps were performed for each fuel/temperature combination to find the knock limit and to assess each fuels' sensitivity to spark timing and temperature. The findings were that E85 has lower sensitivity to spark timing in terms of NIMEP loss for deviation from MBT timing. A 5% loss in NIMEP was seen at 3° of spark advance or retard for gasoline, whereas E85 took 5' to realize the same drop in NIMEP. Gasoline was also much more sensitive to intake air temperature changes than E85. Increasing the intake air temperature for gasoline decreased the peak pressure, however, knock onset began earlier for the higher temperatures, indicating that end-gas autoignition is more dependent on temperature than pressure. E85's peak pressure sensitivity to spark timing was found to be about 50% lower than that of gasoline and it displayed much higher knock resistance, not knocking until the intake air temperature was 130°C with spark timing of 30° bTDC. These results give some insight into the effectiveness of ethanol to improve gasoline's anti-knock index. Future experiments will aim to quantify charge cooling and anti-knock properties, and determine how ethanol concentration in gasoline/ethanol blends effects this knock suppression ability.
by Justin E. Negrete.
S.B.
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Wiklund, Eric, and Claes Forssman. "Bypass Modeling and Surge Control for turbocharged SI engines." Thesis, Linköping University, Department of Electrical Engineering, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-3594.
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Since measurements in engine test cells are closely coupled with high costs it is of interest to use physically interpretable engine models instead of engine maps. Such engine models can also be used to do off-line tests of how new or altered components affects engine performance.
In the thesis an existing mean value engine model will be extended with a model of a compressor bypass valve. A controller for that valve will also be developed. The purpose with that controller is to save torque and boost pressure but at the same time avoid having the compressor entering surge during fast closing transients in the throttle position.
Both the extension and controller is successfully developed and implemented. The extension lowers the pressure after the compressor and increases the pressure before the compressor when the bypass valve is being opened and the controller shows better results in simulations than the controller used in the research lab. By using the proposed controller, as much as 5 percent higher torque can be achieved in simulations.
Finally there is a discussion on wastegate control alternatives and the use of TOMOC for optimization of wastegate control.
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Assanis, Dennis N. "A computer simulation of the turbocharged turocompounded diesel engine system for studies of low heat rejection engine performance." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/15089.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1986.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.
Bibliography: leaves 135-140.
by Dionissios Nikolaou Assanis.
Ph.D.
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Westin, Fredrik. "Simulation of turbocharged SI-engines - with focus on the turbine." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-216.
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Brandon, Sidney Jordan. "Effects of Heat Addition After the Exhaust Valve on a Small Turbocharged Diesel Engine." Thesis, Virginia Tech, 2006. http://hdl.handle.net/10919/31874.
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Designers of engines have always looked for ways to improve the power to weight ratio of mobile internal combustion engines. This was especially true in aircraft engine design and engines for various forms of racing. Today designers are looking for ways to make everything from cars to road tractors to farm tractors lighter and thereby more efficient. In addition, in many cases these vehicles only need the maximum power that an engine can produce for a small amount of time. What is needed is a small, lightweight engine with the ability to produce a large amount of power for a short duration.
The work here describes one possible method for constructing just such a type of engine. By adding a combustion chamber in the exhaust flow between the engine exhaust valve and the turbine inlet on a turbocharged diesel engine, it should be possible to increase the turbine temperature. This will in turn allow the turbine to deliver more power to the compressor and create a higher inlet pressure and allow the engine to create more power. This paper describes both a computer simulation and an engine with this combustion chamber installed. There were however, problems with both the simulation as well as the test engine. While no quantitative data was obtained from the test engine, some valuable observations were made. The computer simulation yielded results and from these results and observations made while testing the engine with the combustion chamber installed it was determined that this design shows promise of creating an engine with higher specific power.Master of Science
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Degong, Dang. "Theoretical and experimental diesel engine system studies, with special reference to temperature and altitude derating." Thesis, University of Bath, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234139.
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Klasén, Erik. "Modeling and Estimation of Long Route EGR Mass Flow in a Turbocharged Gasoline Engine." Thesis, Linköpings universitet, Fordonssystem, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-131102.
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Due to the continuous work in the automobile industry to reduce the environmental impact, reduce fuel consumption and increase efficiency, new technologies need to be developed and implemented in vehicles. For spark ignited engines, one technology that has received more attention in recent years is long route Exhaust Gas Recirculation (EGR), which means that exhaust gases after the turbine are transported back to the volume before the compressor in the air intake system of the engine. In this work, the components of the long route EGR system is modeled with mean value engine models in Simulink, and implemented in a existing Simulink engine model. Then different methods for estimating the mass flow over the long route EGR system are compared, and the transport delays for the recirculated exhaust gases in the engines air intake system are modeled. This work is based on measurements done on an engine rig, on which a long route EGR system was installed. Finally, some ideas on how a long route EGR system on a gasoline engine can be controlled are presented based on the results in this thesis work.
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Jager, Dennis John. "A study of mixing and combustion in a divided chamber turbocharged natural gas engine." Thesis, University of Bath, 1992. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304836.
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Jung, Merten. "Mean-value modelling and robust control of the airpath of a turbocharged diesel engine." Thesis, University of Cambridge, 2003. https://www.repository.cam.ac.uk/handle/1810/265454.
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This thesis investigates mean-value modelling and robust control of the airpath of a diesel engine equipped with variable geometry turbocharger (VGT) and exhaust gas recirculation (EGR). Both the EGR and the VGT are driven by the exhaust gas and render the control problem inherently multivariable. In order to allow for model-based control design, a mean-value model of the airpath of the engine is derived with a focus on the parameterisation of the turbocharger. The effect of heat transfer via the turbocharger housing on the efficiencies derived from temperature measurements is identified as being very significant at low speed and load points regularly met on emission drive cycles. A physics-based parameterisation for the turbine efficiency map, which is the most difficult to model, is suggested. Based on experimentally obtained frequency responses, the parameters which are most uncertain in the model, i. e. compressor and turbine efficiency as well as the effective area of the EGR valve, are identified to have the biggest effect on the frequency responses. Different parameterisations of these uncertainties are then used for extended Je00 loopshaping design at a fixed engine operating point. Applying ?, analysis tools, it turns out that the application tailored uncertainties yield a better controller performance, which is confirmed by experimental data. In order to extend the controller operating regime, the nonlinear model is simplified and converted to linear parameter-varying (LPV) form . A robustly gain scheduled LPV controller is synthesised for this model using a gridding approach for the intake manifold pressure as scheduling variable. The designed controller is implemented on the engine in real-time. The experimental results are very promising and indicate that the quasi-LPV model captures the significant nonlinearities and dynamics of the plant.
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Jones, Alan Llewellyn. "The performance of a turbocharged spark-ignition engine fuelled with natural gas and gasoline." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25101.
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This thesis presents an investigation of the influence of turbocharging on the performance and combustion behaviour of a dual fuelled, spark-ignition engine fuelled with natural gas and gasoline.
The investigation was carried out using a combination of experimental and analytical methods. The experimental data was obtained from an instrumented, four cylinder, Toyota engine mounted in a test cell. An electrically driven Roots blower was used to provide compressed air to the engine, and a restriction was placed in the exhaust pipe to simulate the effects of an exhaust-driven turbine.
Cylinder pressure data were recorded and analysed using a computer routine in order to provide information on mass burning rates and burning velocities. Computer routines were also developed to simulate the compression, combustion and expansion processes in the engine.
It was found that the laminar burning velocity of natural gas is 50% to 60% lower than gasoline, under engine-like conditions of temperature and pressure. Mass-burning rate analyses of measured cylinder pressure data showed that the lower burning velocity of natural gas has its greatest influence during the ignition delay period (up to 1% mass burned) and that it can cause increases in ignition delay of between 50% and 100% relative to gasoline. It was observed that the low burning velocity of natural gas also affects the main combustion period, but to a much lesser extent, increasing it by up to 10% relative to gasoline. It was concluded that the main combustion period is dominated by turbulence effects and that it is relatively unaffected by variations in fuel type, air/fuel ratio or boost pressure.
Results from the engine tests and simulation program indicated that it is possible to recover the power loss experienced by an engine running on natural gas by boosting the intake pressure to 3 psig (20 kPa) above that provided when the engine is running on gasoline. This increase in boost pressure does not significantly reduce the efficiency or raise the specific fuel consumption. It was found, however, that the peak cylinder pressures attained can be as much as 20% higher on natural gas than on gasoline at the same power level.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Lindén, Erik, and David Elofsson. "Model-based turbocharger control : A common approach for SI and CI engines." Thesis, Linköpings universitet, Institutionen för systemteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-70288.
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In this master’s thesis, a turbine model and a common control structure for theturbocharger for SI and CI-engines is developed. To design the control structure,simulations are done on an existing diesel engine model with VGT. In order tobe able to make simulations for engines with a wastegated turbine, the model isextended to include mass flow and turbine efficiency for that configuration. Thedeveloped model has a mean absolute relative error of 3.6 % for the turbine massflow and 7.4 % for the turbine efficiency. The aim was to control the intake manifoldpressure with good transients and to use the same control structure for VGTand wastegate. By using a common structure, development and calibration timecan be reduced. The non-linearities have been reduced by using an inverted turbinemodel in the control structure, which consists of a PI-controller with feedforward.The controller can be tuned to give a fast response for CI engines and a slowerresponse but with less overshoot for SI engines, which is preferable.
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Jo, Young Suk. "More effective use of fuel octane in a turbocharged gasoline engine : combustion, knock, vehicle impacts." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/104246.
Full textAbstract:
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages [146]-151).
Turbocharging, increasing the compression ratio, and downsizing a spark-ignition engine are well known strategies for improving vehicle fuel economy. However, such strategies result in higher in-cylinder pressures and temperatures which increase the likelihood of engine knock above that of naturally-aspirated engines. A high octane fuel, such as E85, effectively suppresses knock but the octane ratings of such fuels are much above what is required under normal driving conditions. To address this issue, there have been attempts to use octane more effectively by means of Octane on Demand (OOD): higher octane fuel is used only when needed. Engine experiments were performed to understand the combustion characteristics and knock limits of a commercially available turbocharged spark ignition engine. By utilizing data from engine experiments and engine-in-vehicle simulations, this study quantifies the octane requirement of a 2-liter turbocharged engine over its operating range as well as for various driving cycles. The average octane ratings of fuel needed in real-world driving were in the 60-80 RON range (maximum RON required around 90-100.) Engine configurations (boost/downsizing level, compression ratio), spark retard strategies, and vehicle configurations (vehicle type and loading conditions) were important parameters deciding these octane requirements. To analyze the effects of downsizing, retarding spark timing, increasing compression ratio, and vehicle type on dual fuel applications, GT-power simulation was conducted along with engine experiments and engine-in-vehicle simulations for a passenger vehicle and a medium-duty truck. Parametric studies were conducted to analyze the effects of listed variables on the vehicle fuel consumption, ethanol usage, and average engine efficiency. Downsizing a naturally-aspirated engine by 50% resulted in about a 30% increase in fuel economy. Ethanol consumption varied from 5 to 40% (by volume) of the total fuel used, depending on the details. Moderate amounts of spark retard reduced ethanol consumption by half while not deteriorating fuel economy significantly. Increasing compression ratio above 11.5 had a marginal return in fuel economy while demanding a significantly larger amount of ethanol. Finally, two dual fuel systems (twotank and on-board fuel separation) were modeled to compare benefits and disadvantages. Additionally, a new cycle-by-cycle pressure analysis method is presented, which help better explain the cycle-by-cycle variations of the spark ignition engine combustion process.
by Young Suk Jo.
Ph. D.
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Zhou, Junqiang. "CONTROL OF OVER-ACTUATED SYSTEMS WITH APPLICATION TO ADVANCED TURBOCHARGED DIESEL ENGINES." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420810533.
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Rämmal, Hans. "Studies of flow duct acoustics with applications to turbocharged engines." Doctoral thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10590.
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A number of experimental and theoretical studies, performed in the field of technical flow duct acoustics are presented in this thesis. The acoustical methods treated are implemented on turbocharged IC-engines and engine gas exchange system components. A new method based on the well-known two-load technique has been developed. The method was applied to characterise the source data of various piston-engines with non-linear behaviour including a 6 cylinder turbo-charged truck diesel engine. The source characterisation results were compared to the results obtained using the linear two-load technique. It was demonstrated that the new non-linear multi-load technique gives improved results when the source is slightly non-linear. The use of active one-port models has been tested to characterize an air terminal device (ATD) as a source of flow generated noise. In order to predict the noise generation at different operating points of the device a scaling law was derived and verified. In the experimentally derived scaling law a flow speed dependence of 3 was found for the narrow band spectra, corresponding to a dipole-like behavior of the source in the plane wave range. The proposed technique was validated successfully and the results indicated a good prediction of in-duct sound generation by the air terminal device. Sound reflection from hot flow duct openings has been investigated experimentally. The reflection coefficient was measured for flow temperatures up to 500 ºC and jet velocities up to 108m/s. The results have been compared with famous Munt’s theory. It was concluded that at low Mach number and Helmholz number cases the results agree well with the Munt’s model. This was the first experimental validation of the theory for hot flow conditions. Experimental procedures to determine the sound transmission through automotive turbo-charger compressors were developed and described in detail. An overview of a unique turbocharger testing facility established at KTH CICERO in Stockholm is given. The facility can be used to measure acoustic two-port data for turbo-compressors. Results from measurements on a passenger car turbo-compressor are presented and the influence of operating conditions on the sound transmission is discussed. Current wave action models developed in CMT for computation of the gas exchange processes in I.C. engines have been implemented to determine the acoustic wave transmission through the turbo- compressor. The models are validated with the experimental data and the results are presented for different operating conditions of a Volvo passenger car turbo-compressor.QC 20100809
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Backhouse, R. J. "The dynamic behaviour and feedback control of a turbocharged automotive diesel engine with variable geometry turbine." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.375340.
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Silvestri, Nicola. "Development, testing and potential benefits of a closed-loop combustion controller on a turbocharged GDI engine." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/12610/.
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Nei motori ad accensione comandata, la fase della combustione rappresenta uno dei principali parametri che influenzano l’efficienza di conversione dell’energia chimica del combustibile in lavoro meccanico.
L’istante in cui viene dato il comando di accensione, detto ‘anticipo’, viene attualmente controllato in catena aperta per mezzo di mappe salvate nella centralina elettronica di controllo motore.
Un’alternativa è costituita da un sistema di controllo dell’anticipo di accensione in catena chiusa su di una misura reale del processo di combustione, in modo da regolare l’anticipo per produrre sempre una corretta fasatura della combustione. Tuttavia, l’implementazione di un sistema basato su di una misura di pressione all’interno del cilindro, a causa di costi elevati e problemi di affidabilità dei sensori, non è per il momento perseguibile nell’ambito di applicazioni industriali. Un’alternativa al segnale di pressione è costituita dalla misura della corrente di ionizzazione, effettuata usando la candela stessa come sensore.
Nell’ambito di questo lavoro di tesi è stata condotta una campagna di misure sperimentali per quantificare il livello di correlazione tra alcune caratteristiche del segnale di corrente di ionizzazione e gli indici impiegati per descrivere la fase di combustione derivati dal segnale di pressione.
La fase di implementazione ha portato allo sviluppo e alla sperimentazione di un innovativo controllo in catena chiusa dell’anticipo di accensione. Il sistema è stato testato tramite un ambiente di simulazione appositamente sviluppato e successivamente implementato e collaudato su di un motore Ferrari sovralimentato, al banco prova ed in vettura. Il risultato principale è quindi un innovativo sistema di controllo dell’anticipo, cilindro per cilindro, che è in grado di adattare continuamente l’attuazione sia alla variazione dei parametri interni di funzionamento del motore, sia a quelli esterni.
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Glenn, Bradley C. "Coordinated control of the turbo electrically assisted variable geometry turbocharged diesel engine with exhaust gas recirculation." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1127225590.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xv, 178 p.; also includes graphics (some col.). Includes bibliographical references (p. 153-158). Available online via OhioLINK's ETD Center
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Mrosek, Matthias. "Model-based control of a turbocharged diesel engine with high- and low-pressure exhaust gas recirculation." Phd thesis, VDI Verlag, 2017. https://tuprints.ulb.tu-darmstadt.de/6960/1/Dissertation_Mrosek_TUprints.pdf.
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Modern Diesel engines fulfil challenging requirements for emission limits, fuel consumption and ride comfort by numerous modular combinable components and mechatronical actuators. These components are utilised for precondition and aftertreatment of air, fuel and exhaust gas, which is involved in the combustion process. In this dissertation a methodology for a model-based function development with semi-physical engine models for control of air path quantities of an exemplary Diesel engine with high-pressure (HP-EGR) and low-pressure exhaust gas recirculation (LP-EGR) is developed. In this framework for function development black-box models for stationary and dynamical emission formation are utilised to optimise reference values for the air path control and to rate the developed control scheme with regard to the cumulated driving cycle emissions of the new European driving cycle (NEDC).
A combination of HP-EGR and LP-EGR represents a novel approach to significantly lower the particulate and NOx emissions of Diesel engines. A semi-physical mean value engine model with lumped parameters is the base to analyse the system properties of the complex air path. In doing so, the additional LP-EGR shows only minor influences to the quantities charge air pressure and HP-EGR, while there are significant influences of these quantities on the LP-EGR mass flow rate. Furthermore, the LP-EGR is characterised by significant gas propagation times in the intake and exhaust system. These delays are modelled by a gas composition model, which is incorporated into the control scheme.
NOx and particulate emissions as well as engine torque are stationary modelled by local polynomial models with input quantities of the combustion process. These quantities are air mass flow rate, charge air pressure, intake temperature and crank angle of 50% mass fraction burned. A bilinear interpolation between engine speed and injection quantity transforms local polynomial models into global models. Models for the dynamical emission formation are given by considering the combustion as a batch process. Consequently all dynamics are included in the quantities of the cylinder charge at intake valve closing and the emission measurement dynamics. Thus, a combination of a dynamical gas composition model, stationary emission models and models for the emission measurement dynamics yield the dynamical course of the engine emissions.
The investigated system properties and the emission models deliver the control variables charge air pressure, air content and intake temperature for the engine with VGT-turbocharger, HP- and LP-EGR. A stationary optimisation with regard to emissions and engine torque delivers reference values for the air path control and further shows the potential of the LP-EGR to lower the emissions. Due to the multi-variable characteristics of the air path with different dynamics, there are increased dynamical emissions at engine transients. These dynamical emissions are lowered by dynamical optimised reference values for the air path control.
Generally, the air path is a strongly nonlinear process and the multitude of engine variants and engine operation modes result in a trade-off between achievable control quality, control robustness and number of control parameter sets. A semi-physical feedforward control, which is based upon parameterised model relationships of the mean value engine model delivers a good response to setpoint changes. Thus, the disturbance rejection can be achieved by relatively simple controllers. This results in an significantly lower application effort of control parameters and allows by its modular structure to exchange engine components without the drawback to completely re-parameterise the control parameters. A reference value transformation with modelled states of the gas composition model compensates long gas propagation times in the intake and exhaust system and delivers an optimal air content in the cylinder charge. All control concepts are validated with measurements at the engine test bench. Finally, the derived control concepts for the LP-EGR are compared to the classical HP-EGR control with regard to the cumulated driving cycle emissions. In this investigation the proportion of stationary and dynamical emissions is clearly quantified.
In a nutshell this dissertation is an important contribution for model-based optimisation and function development for the air path control of Diesel engines. The given combination of models for dynamical emission formation, dynamically optimised reference values for the air path control and semi-physical control design are a holistic framework to master the complexity and variance of future Diesel and gasoline engines.
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Glenn, Bradley Charles. "Coordinated control of the turbo electrically assisted variable geometry turbocharged diesel engine with exhaust gas recirculation." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1127225590.
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Rivas, Perea Manuel Eduardo. "Assessment of fuel consumption reduction strategies on a gasoline turbocharged direct injection engine with a cooled EGR system." Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/68497.
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[EN] This research work presents the study of a low pressure EGR loop influence on a SI gasoline turbocharged direct injection engine in steady and transient testing conditions, with an optimization process of the original engine calibration in order to minimize the engine fuel consumption when cooled EGR is introduced in steady testing conditions. The cooled EGR strategy was also evaluated operating in synergy with other fuel consumption reduction strategies, such as: lean burn, multi-injection, higher coolant temperature and in-cylinder induced swirl motion.
To fulfill the main objectives of this research work, firstly, a methodical process was followed, where a global methodology was first developed in order to obtain high accuracy engine tests, based on the experimental tools chosen that could comply with the requirements of the testing conditions, and the appropriate theoretical tools and procedure to post-process the tests performed. Secondly, a specific methodology was developed for each stage of the study and testing conditions, taking into account optimization processes or parametric tests in order to study the effect of a single parameter on engine's outputs or optimize an engine parameter in order to minimize the engine fuel consumption.
As a first stage of the study, a basic analysis of the impact of cooled EGR on the engine combustion, performance, air management and exhaust emissions is presented. Afterwards, an optimization of the combustion phasing in order to minimize the fuel consumption was performed, and therefore the potential of cooled EGR in order to reduce the engine fuel consumption was observed for low load, part load and full load engine conditions, for two different engine speeds. In addition, a study in transient conditions of the engine operating with cooled EGR was performed. NEDC cycles were performed with different EGR valve openings and therefore a comparison of different cooled EGR rates influence on the engine performance, air management and accumulated exhaust emissions was presented.
The second stage, consisted in a methodology developed to optimize the VVT setting and injection timing, for part load engine conditions, in order to maximize the cooled EGR potential to reduce engine fuel consumption. After this optimization, a synergy analysis of the optimum engine condition operating with cooled EGR and three other engine fuel consumption reduction strategies was performed. These strategies were tested to investigate and evaluate the potential of increasing the cooled EGR operational range to further decrease the engine fuel consumption. Furthermore, a basic study of the potential to reduce the engine fuel consumption and impact on combustion, air management and exhaust emissions of a lean burn strategy, in part load engine conditions, was presented as introduction of the final study of the cooled EGR strategy operating in synergy with the lean burn strategy in order to investigate the potential to control the exhaust emissions and reduce the engine fuel consumption.[ES] El objetivo de este trabajo de investigación es estudiar la influencia de un lazo de baja presión de EGR en las prestaciones de un motor de gasolina de encendido provocado turbosobrealimentado e inyección directa, en condiciones de ensayos estacionarios y transitorios, con un proceso de optimización de la calibración original del motor para minimizar el consumo de combustible del motor. La estrategia de "cooled EGR" fue también evaluada operando en sinergia con otras estrategias usadas para reducir el consumo de combustible del motor, entre ellas: mezcla pobre, múltiples inyecciones, operación a alta temperatura del fluido refrigerante del motor y movimiento de "swirl" inducido en el cilindro. Para cumplir con los objetivos mencionados, se siguió un proceso metódico donde previamente se desarrolló una metodología global para obtener resultados de indudable calidad, basados en el uso de herramientas experimentales que cumplieran con los requerimientos de las condiciones de ensayo, y las apropiadas herramientas teóricas y procedimiento para post-procesar los ensayos realizados. En segundo lugar, se desarrolló una metodología específica para cada etapa del estudio, teniendo en cuenta los procesos de optimización o estudios paramétricos que se pudieran realizar. Como primera etapa, se presenta un estudio básico del impacto del "cooled EGR" en la combustión, prestaciones, renovación de la carga y emisiones contaminantes del motor. Seguidamente, se procedió a la optimización del centrado de la combustión con la finalidad de minimizar el consumo de combustible del motor y poder analizar el potencial del "cooled EGR" como estrategia de reducción de consumo de combustible. El estudio presentado se realizó para baja, media y alta carga del motor con dos diferentes regímenes de giro del motor. Adicionalmente, se llevó a cabo un estudio del motor operando en condiciones transitorias con "cooled EGR". Se realizaron una serie de ensayos usando el ciclo NEDC como base y se probaron diferentes estrategias sencillas de control de la apertura de la válvula de EGR para analizar la influencia del "cooled EGR" en condiciones transitorias. La segunda etapa consiste en el desarrollo de una metodología para optimizar los parámetros del diagrama de distribución (VVT) y el inicio de inyección, para cargas medias del motor, con la finalidad de maximizar el potencial de reducción de consumo de combustible de la estrategia "cooled EGR". Una vez realizada la optimización, se llevó a cabo un estudio usando la configuración óptima encontrada, operando en sinergia con otras tres estrategias usadas para reducir el consumo de combustible del motor. Estas estrategias fueron evaluadas con la finalidad de incrementar el rango de operación de la estrategia "cooled EGR" para lograr reducir aún más el consumo de combustible del motor. Adicionalmente, se llevó a cabo un estudio básico sobre la influencia de operar con mezcla pobre en la combustión, prestaciones, renovación de la carga y emisiones contaminantes del motor, como introducción al último estudio llevado a cabo sobre la posibilidad de usar la estrategia de mezcla pobre en conjunto con la estrategia de "cooled EGR", con la finalidad de analizar el potencial de controlar las emisiones contaminantes y reducir el consumo de combustible del motor al mismo tiempo.
[CAT] L'objectiu d'este treball d'investigació és estudiar la influència d'un llaç de baixa pressió d'EGR en les prestacions d'un motor de gasolina d'encesa provocat turbosobrealimentat i injecció directa, en condicions d'assajos estacionaris i transitoris, amb un procés d'optimització del calibratge original del motor per a minimitzar el consum de combustible del motor. L'estratègia de "cooled EGR" va ser també avaluada operand en sinergia amb altres estratègies usades per a reduir el consum de combustible del motor, entre elles: mescla pobra, múltiples injeccions, operació a alta temperatura del fluid refrigerant del motor i moviment de `"swirl" induït en el cilindre. Per a complir amb els objectius mencionats, es va seguir un procés metòdic on prèviament es va desenrotllar una metodologia global per a obtindre resultats d'indubtable qualitat, basats en l'ús de ferramentes experimentals que compliren amb els requeriments de les condicions d'assaig, i les apropiades ferramentes teòriques i procediment per a post- processar els assajos realitzats. En segon lloc, es va desenrotllar una metodologia específica per a cada etapa de l'estudi, tenint en compte els processos d'optimització o estudis paramètrics que es pogueren realitzar. Com a primera etapa, es presenta un estudi bàsic de l'impacte del "cooled EGR" en la combustió, prestacions, renovació de la càrrega i emissions contaminants del motor. A continuació, es va procedir a l'optimització del centrat de la combustió amb la finalitat de minimitzar el consum de combustible del motor i poder analitzar el potencial del "cooled EGR" com a estratègia de reducció de consum de combustible. L'estudi presentat es va realitzar per a baixa, mitja i alta càrrega del motor amb dos diferents règims de gir del motor. Addicionalment, es va dur a terme un estudi del motor operand en condicions transitòries amb "cooled EGR". Es van realitzar una sèrie d'assajos usant el cicle NEDC com a base i es van provar diferents estratègies senzilles de control de l'obertura de la vàlvula d'EGR per a analitzar la influència del "cooled EGR" en condicions transitòries. La segona etapa consistix en el desenrotllament d'una metodologia per a optimitzar els paràmetres del diagrama de distribució (VVT) i l'inici d'injecció, per a càrregues mitges del motor, amb la finalitat de maximitzar el potencial de reducció de consum de combustible de l'estratègia "cooled EGR". Una vegada realitzada l'optimització, es va dur a terme un estudi usant la configuració òptima trobada, operant en sinergia amb altres tres estratègies usades per a reduir el consum de combustible del motor. Estes estratègies van ser avaluades amb la finalitat d'incrementar el rang d'operació de l'estratègia "cooled EGR" per a aconseguir reduir encara més el consum de combustible del motor. Addicionalment, es va dur a terme un estudi bàsic sobre la influència d'operar amb mescla pobra en la combustió, prestacions, renovació de la càrrega i emissions contaminants del motor, com a introducció a l'últim estudi dut a terme sobre la possibilitat d'usar l'estratègia de mescla pobra en conjunt amb l'estratègia de "cooled EGR", amb la finalitat d'analitzar el potencial de controlar les emissions contaminants i reduir el consum de combustible del motor al mateix temps.
Rivas Perea, ME. (2016). Assessment of fuel consumption reduction strategies on a gasoline turbocharged direct injection engine with a cooled EGR system [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68497
TESIS
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Acharya, Nachiketh Lingachari, and Saurav Dasgupta. "Performance Investigation & Gas Exchange Assessment of Exhaust Piston–assisted Turbocharged Engine (EPTE) Concept : A simulation-based assessment." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302394.
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There is an increasing stringency in the emission legislation within the transport industry along with ambitious performance demands from the customer side. These have pushed the vehicle manufacturers and relevant component suppliers to develop and integrate a wide portfolio of engine technologies. Turbocharging is one such technical solution deployed by the industry to reduce fuel consumption and thereby CO2 emissions from the tailpipe. The area within which turbocharging has been practiced spans across a variety of vehicle segments including on-road and off-road applications. It has been well established that standard turbocharging comes with a downside of not having the ability to provide suitable efficiency levels across a broad operating range. Furthermore, four-stroke turbocharged engines with fewer cylinders have uneven exhaust pulsations flowing into the turbine inlet. This implies that the turbocharger is not able to meet the air system demands throughout the engine cycle. There are existing commercial technologies such as twin-scroll turbocharging, Variable Geometry Turbochargers (VGTs) and Electrically-assisted Turbochargers (EAT) to tackle the above highlighted challenges. However, they induce high cost and overall system complexity. A patented concept also referred to as the Exhaust Piston-assisted Turbocharged Engine (EPTE) claims to address the aforementioned drawbacks related to various turbocharging strategies. The EPTE concept uses an extra piston-cylinder which acts solely as a compressor and expander for the exhaust gases flushing out of the combustion cylinders. This extra piston-cylinder is also referred to as the Exhaust Cylinder (EXC) component. This thesis investigates the performance and gas exchange metrics of the EPTE concept across a broad engine speed range, and further compares those against a baseline engine which does not incorporate the EXC component. Gas exchange metrics were evaluated to assess the impact of the EXC component on the performance of turbocharger and sizing of the muffler and aftertreatment system. Performance analysis was conducted for the EXC component to quantify its contribution to the total brake power produced at the crankshaft. The investigation was performed using the commercial engine performance prediction tool, GT-PowerTM. Additional outcomes of the study included evaluation of Normalized Brake Torque (NBT) fluctuation and the hardware modifications in the intake and exhaust side required while transitioning from baseline engine to EPTE. An evaluation of the EXC component specifications was also conducted in this thesis to provide an overview of the extra piston-cylinder from the design standpoint. The EPTE concept proved to be more fuel efficient while producing higher power output than the baseline engine at high boost pressure limits. The new concept exhibited disadvantages from the fuel efficiency and power output standpoint at low boost pressure limits. The concept proved to also increase the performance of the turbocharger by providing a smoother exhaust pressure pulse to the turbine across the engine cycle, when compared against the baseline engine. Furthermore, it had a positive impact on the aftertreatment sizing and flywheel inertia. Another observation was that the EPTE concept can produce such benefits while not having the need to radically modify the intake and exhaust geometrical parameters. With a smaller turbocharger, such an engine proved to be beneficial compared to the baseline engine across the whole engine operating range. The thesis project provides a simulation-based system-level perspective of the EPTE concept which has been patented by Mats Olshammar. Such a system-level perspective will help to gain an understanding of the operation of the EPTE before commencing any hardware development initiatives. The report also provides some recommendations for future work, based on the advantages and disadvantages of the engine concept emanating from the results of the work.Ökade krav i lagstiftningen för utsläpp inom transportindustrin, tillsammans med ambitiösa krav på effekt och bränsleekonomi från kundsidan, har drivit fordonstillverkarna och relevanta leverantörer av komponenter att utveckla och integrera en bred portfölj av motorteknik. Turboladdning är en sådan teknisk lösning som används av industrin för att minska bränsleförbrukningen och därmed koldioxidutsläpp från avgasröret. Området inom vilket turboladdning har praktiserats sträcker sig över en mängd olika fordonssegment, för både vägtrafik och offroad-applikationer. Det är välkänt att standard turboladdning har en nackdel, då den inte har förmågan att tillhandahålla god effektivitet över ett brett driftsområde. Dessutom har fyrtaktsmotorer med få cylindrar ojämna avgaspulser som strömmar in i turbons turbin. Detta gör att turbon inte klarar systemets krav på lufttillgång under motorns hela cykeln. Det finns befintliga kommersiella teknologier som turboladdning med ”twin-scroll”, turbo med variabel geometri (VGT) och elektriskt assisterad turbo (EAT) för att hantera ovanstående utmaningar. Men de medför höga kostnader och övergripande systemkomplexitet. Ett patenterat konceptet, även kallat EPTE (Exhaust Piston-assisted Turbocharged Engine), hävdar att det adresserar dessa nackdelar med olika strategier för turboladdning. EPTE-konceptet använder en extra kolv och cylinder, som enbart komprimerar och expanderar de avgaser som kommer från förbränningscylindrarna. Denna extra kolv och cylinder kallas även EXC (Exhaust Cylinder). Denna avhandling undersöker EPTE-konceptets prestanda och gasutbyte över ett brett motorvarvtal, och jämför detta med en basmotor som saknar EXC-komponenten. Utvärdering görs för att bedöma effekten av EXC-komponenten på turbon prestanda, samt dimensionering av ljuddämparen och system för efterbehandling av avgaser. Prestandaanalys har utförd för EXC-komponenten för att kvantifiera dess bidrag till den totala bromseffekten som produceras vid vevaxeln. Undersökningen utfördes med hjälp av det kommersiella verktyget för motorprestanda, GT-PowerTM. Ytterligare resultat av studien inkluderade utvärdering av fluktuationer i NBT (Normalized Brake Torque) och de fysiska förändringar på insugs- och avgassidan som krävs när basmotorn byggs om till EPTE. En utvärdering av specifikationerna för EXC-komponenten görs också i denna avhandling, för att ge en överblick över den extra kolven och cylindern från konstruktionssynpunkt. EPTE-konceptet visade sig vara mer bränsleeffektivt och gav samtidigt högre effekt än basmotorn, när laddtrycket hade ett högt satt värde för begränsning av trycket. Det nya konceptet uppvisade nackdelar gällande bränsleeffektivitet och effekt vid lågt laddtryck. Konceptet visade sig också öka turbons prestanda genom att ge turbinen ett jämnare avgasflöde/tryck över motorns hela cykel, detta jämfört med basmotorn. Konceptet hade också en positiv inverkan på ljuddämpare och system för efterbehandling av avgaser, samt för storleken på motorns svänghjul, då alla dessa komponenter kunde minskas i dimension. Det observerades också att EPTE-konceptet kan ge dessa fördelar utan att behov av stora modifieringar av insugs- och avgassidans geometriska parametrar. Med en mindre turboladdare visade sig en sådan motor vara fördelaktig, jämfört med basmotorn, över hela motorns varvtalsregister. Avhandlingen ger ett simuleringsbaserat perspektiv på systemnivå av EPTE-konceptet, som har patenterats av Mats Olshammar. Ett sådant perspektiv på systemnivå bidrar till en förståelse för EPTE innan man påbörjar några initiativ för utveckling av hårdvara. Rapporten ger också några rekommendationer för framtida arbete, baserade på de fördelar och nackdelar som konceptmotorn uppvisar i detta arbete.
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Ward-Santos, Orlando. "Design and analysis of a turbocharged single cylinder diesel engine intake system for increased power output and transient response." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112526.
Full textAbstract:
Thesis: S.B., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (page 35).
Small displacement, single-cylinder diesel engines have many applications in developing countries such as small-powered agricultural equipment, water pumps, and other power sources. Research has shown that the power of a turbocharged single-cylinder engine can match that of a larger displacement multi-cylinder, naturally aspirated engine, at a fraction of the cost. The valve timing mismatch that occurs when turbocharging a single cylinder engine is solved by adding a large volume air intake as a buffer for the pressurized air. This thesis explores the design, methodology, and testing of modifying the additional air intake to passively varying its volume during operation. Mechanical design of the variable volume air capacitor is established. Next, the experimental setup is discussed. Finally, both steady state and transient experimental results are discussed.
by Orlando Ward-Santos.
S.B.
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Růsek, Lukáš. "Plnící turbodmychadlo." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2009. http://www.nusl.cz/ntk/nusl-228804.
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A masters thesis deals with the question of deisel engine boosting by rotary turbochargers. The objective of the thesis is to propose suitable turbocharger´s concept for defined diesel combustion engine with power of 430 [kW]. The air boosting pressure is controlled by exhaust gas flow through the turbine and different EGR regimes, which are considered in the basic and corrected calculations. The final turbocharger´s concept is proposed to satisfy the defined technical requirements. Next technical recommendations are briefly summarized in the thesis conclusion for following turbocharger´s concept application.
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Mrosek, Matthias Patrick Alexander [Verfasser], Rolf [Akademischer Betreuer] Isermann, and Ulrich [Akademischer Betreuer] Konigorski. "Model-based control of a turbocharged diesel engine with high- and low-pressure exhaust gas recirculation / Matthias Patrick Alexander Mrosek ; Rolf Isermann, Ulrich Konigorski." Darmstadt : Universitäts- und Landesbibliothek Darmstadt, 2017. http://d-nb.info/1145141935/34.
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Keller, Martin [Verfasser], Dirk [Akademischer Betreuer] Abel, and Stefan [Akademischer Betreuer] Pischinger. "Two-stage model predictive control for the air path of a turbocharged gasoline engine with exhaust gas recirculation / Martin Gerhard Keller ; Dirk Abel, Stefan Pischinger." Aachen : Universitätsbibliothek der RWTH Aachen, 2021. http://d-nb.info/123852379X/34.
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Barros, Bruno Vinícius de menezes'. "Efeito da contrapressão e do resfriamento da turbina no desempenho de um motor diesel ottolizado para gás natural." Universidade Federal da Paraíba, 2015. http://tede.biblioteca.ufpb.br:8080/handle/tede/8976.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
The cost of the kWh at the peak hour in Brazil may be up to nine times higher than the one at normal hours. This fact has served as motivation for industries, shopping malls, hotels, and so on, to utilize electrical generators. These generator sets generally comprise Diesel engines. The problem is that the exhaust gases from these engines are very harmful to health. On the other hand, Natural Gas, thanks to its high calorific power and its low emissions, is considered a clean-burning alternative fuel. Therefore, the Diesel engines converted to Otto cycle may considerably reduce the environmental pollution. Such a conversion, however, may have in turbocharged engines backpressure effects that increase the temperature of the turbine, reducing the energy efficiency of the engine. The present study analyzes the result and consequences of the replacement of the original manifold by another with smoother curves, as well as the cooling effect on the engine performance of the turbine of a Perkins turbocharged model 1104C-44TAG2, converted to the Otto cycle. First, tests were made running the engine with its original manifold without any cooling, and then, having the turbine cooled with room air. After the replacement of the manifold, new teste were performed. Initially, without cooling the turbine or the manifold. Then, after the replacement of the manifold, other tests ventilating the turbine and the manifold were made. In each test, one has registered: the maximum operation power; temperature of the exhaust gases and the engine consumption in terms of the backpressure due to the manifold. All the tests were performed with the aid of a hydraulic dynamometer. It was noted that the use of the new manifold allowed the reduction on the backpressure. Concerning the maximum power registration there was no difference in terms of the original or the new manifold, because what had limited the power was the temperature on the turbine, which was set at 660 oC. Therefore, whenever the temperature reached this limit, the engine was deliberated stopped. This fact also explains why the ventilation has allowed higher engine powers. The new manifold resulted in fuel reductions.
O valor do kWh, no horário de pico, no Brasil, pode ser até nove vezes maior do que aquele cobrado, fora do dito período, estimulando a indústria, shopping centers, hotéis, etc. a fazerem uso de grupos geradores. Tais grupos são, em geral, compostos por motores a diesel e gerador elétrico. O lado negativo destes motores advém da larga poluição ambiental que produzem. Por sua vez, o Gás Natural, graças ao seu elevado poder calorífico e pela baixa contaminação, quando queimado, é considerado um combustível nobre, alternativo ao diesel. Assim, o uso de motores Diesel turbinados, convertidos para o ciclo Otto, pode reduzir significativamente a poluição ambiental. Nessa conversão, um dos aspectos observados é a influência da contrapressão causada pelo sistema de exaustão dos gases de escape, que contribui para o aumento da temperatura da turbina do motor convertido. O presente trabalho analisa os efeitos da substituição do coletor de escape original por outro, de curvas mais suaves, como também o resfriamento da turbina, no desempenho de um motor Perkins turboalimentado, modelo 1104C-44TAG2, ottolizado para gás natural. Os testes foram realizados com os dois coletores de escape, em operações com e sem refrigeração (por ventilação) da turbina e do coletor. A cada teste, eram avaliados: a potência máxima de operação, a temperatura dos gases de escape e o consumo do motor, em função da contrapressão do sistema de exaustão. Tais testes foram realizados, com o auxílio de um dinamômetro hidráulico, e os resultados mostraram que, de fato, houve uma redução da contrapressão, com a substituição do coletor. No entanto, o motor Perkins ottolizado respondeu, de forma semelhante, para os dois coletores, no que diz respeito à potência máxima alcançada, variando somente devido aos efeitos provocados com e sem resfriamento da turbina e do coletor. Deve-se observar, todavia, que a limitação no valor da potência deveu-se às temperaturas alcançadas pela turbina, de aproximadamente 660 °C. Assim, com resfriamento da turbina, o motor atingiu potências mais elevadas. Verificou-se, ainda, que a modificação do coletor contribuiu para a redução do consumo do motor.
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Žilinský, Ondřej. "Píst zážehového motoru na bioethanol." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254398.
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The aim of this thesis is to design Husqvarna FE 501 turbocharged engine piston for Formula Student competition using bioethanol as its fuel. Proposed concept originates in background research on design solutions of modern combustion engine pistons. FEM simulations are used for piston design.
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Hájek, Daniel. "Zvýšení pružnosti zážehového motoru přeplňováním." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-228975.
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The master’s thesis deals with the question of petrol engine boosting by rotary turbochargers. The objective of the thesis is to project suitable turbocharger for defined single-cylinder petrol engine. After selecting the suitable turbocharger type it will follow the construction of the computational model of the single-cylinder turbocharged petrol engine in the Lotus Engine Simulation software. In the computational model is boost pressure regulated by the turbine waste gate valve. The result will be the boost pressure values scheme for the highest possible torque so that the maximum combustion pressures will not exceed the value of 9,5 MPa. There are summarized findings and results in the conclusion of the thesis.
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Ismail, Muhammad Izzal. "One-dimensional modelling of pulse separation strategy, waste-gated turbines and electric turbocharger systems for downsized turbocharged gasoline engines." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/58097.
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The demand for CO2 emission reduction for modern road vehicles has seen engine downsizing become a key trend in internal combustion engine design: a smaller engine has reduced pumping, frictional and heat losses, and therefore better fuel economy. Turbocharger technology is one of the enabling technologies, offering lower specific fuel consumption and producing more power for a given engine capacity. The turbocharger matching process, which specifies an appropriate turbocharger design for a particular engine, is crucial in obtaining optimum engine performance. In order to achieve a high level of accuracy in the system-level prediction, high fidelity turbocharger models are required; but such models have not yet reached fruition. The present study has assessed the effect of preserving the exhaust pulse energy from an engine right through to the turbine on the steady and transient engine performance. A combination of appropriate turbine sizing and pulse-divided exhaust manifold was applied, and as a consequence, lower back pressure and improved engine scavenging reduced residual content by 28%, while the brake specific fuel consumption (BSFC) improves by approx. 1.2% on average over speed range. Furthermore, the implementation of electric turbo assist (ETA) system on the engine results in better fuel economy by 2.4%. The present work has also assessed the overall engine performance using a commercial 1-D gas dynamics simulation tool by modelling the waste-gated turbines in a novel manner. This approach has been validated experimentally. The study also examined the benefits of electric turbocharger systems for a highly-downsized engine, a modified version of the baseline engine. Some potential multi-boosting systems were applied, and the overall benefits in terms of engine performance were assessed. An integration of an electric turbocharger and a low-pressure turbine with electric turbo compounding gives the best advantages particularly in pumping loss, residual and transient performance while improving fuel economy in comparison with other systems.
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Hong, C. W. "Computer simulation of turbocharged spark ignition engines." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/47281.
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Ferraz, Fagner Barbosa. "Análise de desempenho de um motor diesel turboalimentado ottolizado para gás natural." Universidade Federal da Paraíba, 2014. http://tede.biblioteca.ufpb.br:8080/handle/tede/5384.
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Previous issue date: 2014-06-30Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
A large number of national companies has been using diesel gensets as an alternative to the electricity supplied by the local utility. Therefore, generators are used as an emergency power system or during peak hours. Peak hour in Brazil is between 5 to 10 p. m. As we know diesel engines contribute to the large increase in environmental pollution, since the diesel exhaust may contain fine particles associated with negative health effect, toxic air contaminants, as NOx and SOx. On the other hand, Natural gas is considered as a suitable choice rather than the use of diesel, because it possesses high calorific power, clean burning, and proper octane level for Otto cycle engine. The present work deals with the performance analysis of a Perkins engine turbocharged, diesel, model 1104C-44TA, converted into an Otto cycle engine to run on natural gas, also identifying the limiting factors of power in these types of engines. Giving the importance of the compression rate on the Diesel to Otto cycle conversion, the evaluation of the Perkins processed engine happened under the influence of three different rates: 7.6:1; 8.7:1 and 12.3:1. For each compressed rate, and stoichiometric mixture, the task was to choose the spark advance to guarantee best performances to the engine. All tests were performed with a hydraulic dynamometer. The results showed that, the best combination of those parameters are not sufficient to ensure the highest performance of a diesel converted engine. There was a consubstantial rise in temperature of the exhaust gases and on the turbine walls, due to the increase in the exhaust gases volume, compared to that of the burnt gases withdrawn from the original engine, impairing the efficiency and lifespan of the engine components. It was found, by energetic analysis, the compression ratio of 8.7:1, was the most efficient, among the other two, assuring the engine its best performance. As expected, at the compression rate of 7.6:1 the exhaust gases presented the highest temperatures. At compression ratio of 12.3:1 the gas emissions of the converted engine delivered highest NOx level and the lowest level of unburned hydrocarbons at the exhaust. Keywords: Diesel Turbocharged Engine. Diesel to Otto Cycle Conversion Process. Natural Gas. Performance. Energy Balance
Um grande número de empresas nacionais faz uso de grupos geradores a diesel como opção à eletricidade fornecida pela concessionária local. O emprego de grupos geradores é comum durante as horas de pico, que no Brasil, ocorrem entre as 17 e 22 h. Tais aparatos, juntamente com os motores veiculares a diesel têm contribuído para o grande aumento da poluição ambiental, uma vez que a queima deste combustível se faz com grande emissão de particulados, de NOx e de SOx. O gás natural é considerado uma alternativa ao uso do diesel por possuir um alto poder calorífico, queima limpa, e adequada octanagem para o ciclo Otto. O presente trabalho trata da análise de desempenho de um motor Perkins turboalimentado, a diesel, modelo 1104C-44TA, convertido para funcionar apenas com gás natural, identificando ainda, os fatores limitadores de potência nestes tipos de motores. Considerando a importância da taxa de compressão no processo de ottolização, o motor convertido foi avaliado sob a influência de três diferentes taxas: 7,6:1; 8,7:1 e 12,3:1. Para tanto, foram selecionados avanços de ignição que ao interagir com a mistura próxima da estequiométrica garantisse ao funcionamento do motor as melhores condições de desempenho, para cada taxa de compressão escolhida. Os ensaios foram feitos com o auxílio de um dinamômetro hidráulico e os resultados obtidos evidenciaram que, na prática, tais parâmetros não são suficientes para se assegurar os melhores desempenhos em um motor diesel ottolizado. Foi observado um aumento consubstancial na temperatura dos gases de exaustão e na turbina, em virtude da ampliação do volume dos gases de escapamento com relação àquele observado no motor original, com prejuízos para a eficiência e a própria vida útil do motor. Verificou-se, através das análises energéticas, que a taxa de compressão de 8,7:1 permitiu ao motor seu melhor desempenho, com relação à outras experimentadas. Como esperado, o motor operando na taxa de 7,6:1 produziu as mais elevadas temperaturas dos gases de exaustão. Com respeito às emissões gasosas, o motor convertido com taxa de compressão de 12,3:1 emitiu o maior nível de NOx e o menor nível de hidrocarbonetos não queimados
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Nishimoto, Keane T. (Keane Takeshi) 1981. "Design of an automobile turbocharger gas turbine engine." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/41810.
Full textAbstract:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.Includes bibliographical references (leaf 24).
The turbocharger gas turbine engine was designed with the intent of being built as a demonstration for the Massachusetts Institute of Technology Department of Mechanical Engineering courses 2.005 and 2.006 to supplement material covered. A gas turbine operates on an open version of the Brayton cycle and consists of a compressor, a combustion chamber and a turbine. An automobile turbocharger was chosen because it contains a compressor and turbine on a common shaft. Designs for the combustion chamber, oil system, fuel system, and ignition system were created based on research of similar projects. Many of the necessary parts were also specified.
by Keane T. Nishimoto.
S.B.
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Andersson, Per. "Air charge estimation in turbocharged spark ignition engines /." Linköping : Dept. of Electrical Engineering, Linköping University, 2005. http://www.bibl.liu.se/liupubl/disp/disp2005/tek989s.pdf.
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Plianos, Alexandros. "Nonlinear modelling and control of turbocharged diesel engines." Thesis, University of Sussex, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.496800.
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The main focus of this thesis is the investigation of nonlinear control designs on the airpath of a diesel engine equipped with exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT). This problem presents strong couplings between controlled variables and actuators, since both EGR and VGT flows are driven by gases in the exhaust manifold. An additional coupling arises from the common shaft of the compressor and the turbine. The multivariable, highly nonlinear dynamics of the system gives motivation for model-based nonlinear control. Firstly, an eighth order mean-value model of the diesel engine is derived. This is consequently used to perform closed-loop simulations and to tune the controller gains offline. To reduce the complexity of the controllers, a third-order mean-value is used to design the nonlinear controllers.