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Rodriguez, Juan Ignacio. "Acoustic excitation of liquid fuel droplets and coaxial jets." Diss., Restricted to subscribing institutions, 2009. http://proquest.umi.com/pqdweb?did=1835606741&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Wilson, Michael. "Integral modelling of jets of variable composition in generalised crossflows." Thesis, University of Bath, 1986. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382563.
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Pianthong, Kulachate Mechanical & Manufacturing Engineering Faculty of Engineering UNSW. "Supersonic liquid diesel fuel jets : generation, shock wave characteristics, auto-ignition feasibilities." Awarded by:University of New South Wales. School of Mechanical and Manufacturing Engineering, 2002. http://handle.unsw.edu.au/1959.4/20325.
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It is well known that high-speed liquid jetting is one of the most powerful techniques available to cut or penetrate material. Recently, it has been conjectured that high-speed liquid jets may be beneficial in improving combustion in such applications as SCRAM jets and direct injection diesel engines. Although there are practical limitations on maximum jet velocity, a fundamental study of the characteristics of high-speed liquid fuel jets and their auto-ignition feasibility is necessary. Important benefits could be increased combustion efficiency and enhanced emission control from improved atomisation. The generation of high-speed liquid jets (water and diesel fuel) in the supersonic to hypersonic ranges by use of a vertical single stage powder gun is described. The effect of the projectile velocity and projectile mass on the jet velocity is found experimentally. Jet exit velocities from a range of different nozzle inner profiles and nozzle hardness are thoroughly examined. The characteristics and behaviour of the high-speed liquid jet and its leading bow shock wave have been studied with the aid of a shadowgraph technique. This provides a clearer picture of each stage of the generation of hypersonic liquid jets. It makes possible the study of hypersonic diesel fuel jet characteristics and their potential for auto-ignition. The fundamental processes by which a supersonic liquid jet is generated by projectile impact have been investigated. The momentum transfer from the projectile to the liquid and the shock wave reflection within the nozzle cavity are the key items of interest. A new one-dimensional analysis has been used in order to simplify this complex and difficult problem. The impact pressure obtained from the projectile was firstly derived. Then, an investigation of the intermittent pressure increase in a closed end cavity and a simple stepped, cross-sectional nozzle were carried out. The nozzle pressure and final jet velocity were estimated and compared to a previous method and to experimental results. Some interesting characteristics found in the experiments relate well to those anticipated by the analysis. The characteristics of a hypersonic diesel fuel jet and its leading edge shock wave were assessed for their potential for auto-ignition using fuel with cetane numbers from 50-100. The investigations were performed at normal ambient air and at elevated air (110 ???C) temperature. So far, there is no sign of auto-ignition that may occur because of the temperature rise of the induced shock.
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Garcia, Fermin N. (Fermin Noel). "A nonlinear control algorithm for fuel optimal attitude control using reaction jets." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/46267.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.Includes bibliographical references (p. 159-161).
We present the analysis and design of a weighted nonlinear time-fuel optimal control algorithm for spacecraft attitude dynamics using on-off gas jets. In the development of a controller, we explore four control algorithms within a single-step control framework where the step is the fundamental update time of the digital controller. The benchmark controller is a basic pulse-width modulator (PWM) with a proportional derivative controller driving the feedback loop. The second is a standard rate-ledge controller (RLC) with full-on or full-off pulse commands, while the third varies the duration of the RLC pulse commands based on the location of the states in the phase plane. The RLC algorithm is shown to well-approximate a continuous-time weighted time-fuel optimal controller. The fourth control algorithm consists of a combination of the variable-pulse RLC algorithm and a tracking-fuel optimal controller that reduces the residual error relative to the latter algorithm. Experimental data from a dynamic air-bearing testbed at Lawrence Livermore National Laboratory are used to compare the four control algorithms. The PWM scheme proves to be robust to disturbances and unmodeled dynamics and quite fast, but yields excessive fuel consumption from frequent switching. The standard RLC algorithm gives poor closed-loop performance in the presence of unmodeled dynamics and ends up being equally as fuel costly as the PWM scheme. The third algorithm, the RLC with variable pulses, significantly improves the transient and steady-state responses of the first two controllers. Via parameter tuning, we observe that this modified RLC gives excellent steady-state fuel consumption as well as reasonably fast settling times. The fourth algorithm, although more fuel efficient than the PWM and standard RLC controllers, is less efficient than the variable RLC algorithm. Matlab simulations of the four control algorithms studied are corroborated by these test results.
by Fermín Noel García.
S.M.
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Wang, Hongjuan. "Simulation of fuel injectors excited by synthetic microjets." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/11862.
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Asay, Rich. "A Five-Zone Model for Direct Injection Diesel Combustion." BYU ScholarsArchive, 2003. https://scholarsarchive.byu.edu/etd/100.
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Recent imaging studies have provided a new conceptual model of the internal structure of direct injection diesel fuel jets as well as empirical correlations predicting jet development and structure. This information was used to create a diesel cycle simulation model using C language including compression, fuel injection and combustion, and expansion processes. Empirical relationships were used to create a new mixing-limited zero-dimensional model of the diesel combustion process. During fuel injection five zones were created to model the reacting fuel jet: 1) liquid phase fuel 2) vapor phase fuel 3) rich premixed products 4) diffusion flame sheath 5) surrounding bulk gas. Temperature and composition in each zone is calculated. Composition in combusting zones was calculated using an equilibrium model that includes 21 species. Sub models for ignition delay, premixed burn duration, heat release rate, and heat transfer were also included. Apparent heat release rate results of the model were compared with data from a constant volume combustion vessel and two single-cylinder direct injection diesel engines. The modeled heat release results included all basic features of diesel combustion. Expected trends were seen in the ignition delay and premixed burn model studies, but the model is not predictive. The rise in heat release rate due to the diffusion burn is over-predicted in all cases. The shape of the heat release rate for the constant volume chamber is well characterized by the model, as is the peak heat release rate. The shape produced for the diffusion burn in the engine cases is not correct. The injector in the combustion vessel has a single nozzle and greater distance to the wall reducing or eliminating wall effects and jet interaction effects. Interactions between jets and the use of a spray penetration correlation developed for non-reacting jets contribute to inaccuracies in the model.
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Rees, Simon John. "Hydrodynamic instability of confined jets & wakes & implications for gas turbine fuel injectors." Thesis, University of Cambridge, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609152.
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Stotz, Ingo [Verfasser]. "Shock Tube Study on the Disintegration of Fuel Jets at Elevated Pressures and Temperatures / Ingo Stotz." München : Verlag Dr. Hut, 2011. http://d-nb.info/1018982434/34.
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Tautschnig, Georg [Verfasser]. "Auto-Ignition and Combustion of Fuel Jets in Vitiated Co-Flow at Elevated Pressure / Georg Tautschnig." München : Verlag Dr. Hut, 2016. http://d-nb.info/1113335971/34.
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Al-Hasnawi, Adnan Ghareeb Tuaamah [Verfasser], and Eckehard [Akademischer Betreuer] Specht. "Mixing behaviour of side injection of air jets and gaseous fuel jets into the axial flow of tunnel kilns / Adnan Ghareeb Tuaamah Al-Hasnawi ; Betreuer: Eckehard Specht." Magdeburg : Universitätsbibliothek, 2016. http://d-nb.info/1117085953/34.
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Al-Hasnawi, Adnan Ghareeb Tuaamah Verfasser], and Eckehard [Akademischer Betreuer] [Specht. "Mixing behaviour of side injection of air jets and gaseous fuel jets into the axial flow of tunnel kilns / Adnan Ghareeb Tuaamah Al-Hasnawi ; Betreuer: Eckehard Specht." Magdeburg : Universitätsbibliothek, 2016. http://nbn-resolving.de/urn:nbn:de:gbv:ma9:1-8342.
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De, Grave Emiel. "Reverse Engineering of Passenger Jets - Classified Design Parameters." Master's thesis, Aircraft Design and Systems Group (AERO), Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, 2017. http://d-nb.info/1204457298.
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This thesis explains how the classified design parameters of existing passenger jets can be determined. The classified design parameters are; the maximum lift coefficient for landing and take-off, the maximum aerodynamic efficiency and the specific fuel consumption. The entire concept is based on the preliminary sizing of jet powered civil aeroplanes. This preliminary sizing is explained in detail because it is the foundation of the final result. The preliminary sizing is combined using reverse engineering which is not a strict method. Therefore, only the basics are explained. By applying reverse engineering on the preliminary sizing and aiming for the classified design parameters as output, formulas are derived to calculate the maximum lift coefficients, the maximum aerodynamic efficiency and the specific fuel consumption. The goal is to calculate these parameters, using only aircraft specifications that are made public by the manufacturer. The calculations are complex with mutual relations, iterative processes and optimizations. Therefore, it is interesting to integrate everything in a tool. The tool is built in Microsoft Excel and explained in detail adding operating instructions. The program is executed for miscellaneous aeroplanes, supported with the necessary comments. Investigated aeroplanes are: Caravelle 10B (Sud-Aviation), Boeing 707-320C, BAe 146-200 (British Aerospance), A320-200 (Airbus), "The Rebel" (based on A320), Boeing SUGAR High, Boeing 747-400, Blended Wing Body VELA 2 (VELA) and Dassault Falcon 8X.
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Castrillon, Escobar Sebastian. "Instabilité et dispersion de jets de corium liquides : analyse des processus physiques et modélisation dans le logiciel MC3D." Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0102/document.
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Lors d’un accident grave dans un réacteur nucléaire (REP ou REB en particulier), le combustible fondu (corium) peut se déverser dans le réfrigérant (eau). L’interaction entre les deux fluides est appelée Interaction Combustible-Réfrigérant. Sous certaines conditions, cette interaction peut conduire à une «explosion de vapeur» qui peut menacer le confinement du réacteur nucléaire. L’ICR est une interaction de caractère multiphasique complexe où divers phénomènes physiques interviennent de manières couplées. Elle débute par une phase de mélange entre les fluides (prémélange), se traduisant par la fragmentation du corium et sa dispersion dans le réfrigérant. Ce processus de fragmentation impacte les échanges thermiques (ébullition et mise en mouvement du fluide environnant (réfrigérant)) et les processus chimiques (oxydation du corium et génération d’hydrogène). Cette thèse apporte de nouveaux éléments concernant la compréhension physique et la modélisation du phénomène de fragmentation du corium, dont l’objectif principal est d’améliorer la modélisation dans le logiciel de thermohydraulique multiphasique MC3D, développé par l’IRSN. L’étude proposée se base sur l’hypothèse de la modélisation de la fragmentation comme un phénomène multi-échelle avec un découplage entre taux de fragmentation du jet et dimension des gouttes résultantes. Elle suppose un processus de fragmentation qui est le résultat d’une déstabilisation primaire (passage jet -> grosses gouttes) pilotée par les grandes échelles de l’écoulement et d’un processus de déstabilisation secondaire menant à une fragmentation finale dépendante des paramètres plus «locaux» de l’écoulement. Nous avons conjugué notre modélisation avec une méthode de type MUSIG récemment introduite dans le logiciel MC3D. Les gouttes de corium y sont représentées, via un découpage en classes, par plusieurs champs de masse et d’énergie avec des diamètres distincts. Malgré les avancées dans la modélisation de la fragmentation, la compréhension des mécanismes et la caractérisation de la fragmentation des gouttes liquides est encore très imparfaite, particulièrement dans le cas liquide/liquide. Le travail de thèse s’est alors orienté vers l’analyse de ce processus en utilisant le logiciel de simulation GERRIS. L’étude conduit à proposer une nouvelle carte de régimes de fragmentation en configuration liquide/liquide, une compréhension plus approfondie de la dynamique de fragmentation et une analyse sur l’interaction vortex-goutte pilotant la transition entre les régimesIn the case of a severe accident in a nuclear power plant, the molten core may flow into water and interact with it. The consequences of this fuel-coolant interaction (FCI) for the follow-up of the accident may be numerous so the phenomenon needs to be described accurately, one of them called “steam explosion” can lead to the failure of the nuclear reactor containment. FCI is a complex multiphase interaction involving several physical phenomena. The premixing phase of the interaction consists in the fragmentation and dispersion of corium in the coolant pool. This phase is driven by the fragmentation process which modifies heat transfers (coolant boiling dynamics) and chemical reactions (corium oxidation and hydrogen generation). This thesis brings new elements about the corium jet and droplet breakup with the main goal of improve fragmentation models on the MC3D multiphase code, developed by the IRSN. Our study is based on a multi-scale fragmentation process where the jet fragmentation rate and final droplet dimensions are not coupled themselves. We suppose a fragmentation process resulting from a primary instability (mass transfer within jet and big droplets) depending on the large flow scales and a secondary instability depending on the small flow scales (leading to final droplet breakup). This model has been implemented in MC3D in combination with the MUSIG method recently added to MC3D. In this method, droplets are represented using several classes, each of them with their own droplet diameter, mass and energy fields. Despite new improvements on modeling corium fragmentation, there is still a lack on the comprehension and characterization on the liquid droplet fragmentation, particularly on liquid/liquid configurations. In this thesis, we study in detail droplet breakup using the computational fluid dynamics software GERRIS. As a result, we find a new droplet breakup classification in liquid/liquid configurations, we improve the droplet breakup dynamics comprehension and we analyze the droplet-vortex interaction to determine breakup regime transition
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Rohaly, Matthew Joseph. "Decomposition of Aromatic Amines in a Jet Fuel Surrogate." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1417777531.
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Hui, Xin. "Flame Studies on Conventional, Alternative, and Surrogate Jet Fuels, and Their Reference Hydrocarbons." Case Western Reserve University School of Graduate Studies / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=case1354909906.
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McMasters, Brian Philip. "Effect of Fuel Chemical Composition on Pyrolytic Reactivity and Deposition Propensity under Supercritical Conditions." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1398682863.
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Merling, Weston Lee. "Assessing the Compatibility of Alternative Jet Propulsion and Diesel Fuels with Selected Fuel System Elastomers." University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1343399395.
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Flora, Giacomo. "Fuel Structure Effects on Surrogate Alternative Jet Fuel Emission." University of Dayton / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1450286398.
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Blochel, Amanda. "The Future of Advanced Bio-Jet Fuel." Thesis, Linköpings universitet, Biologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-138629.
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The aviation industry is growing rapidly and the carbon dioxide emissions from the industry are following in the same manner. Biofuels made from edible feedstock have had an impact on lowering the emissions but at the same time an impact on increasing food prices. There are a few alternative fuels on the market today (TF-SPK, HEFA-SPK) which work in a blend with the petroleum based fuels, reducing the emissions from the aircrafts. Biofuels from next generation biomass, also called advanced biomass, such as algae and lignin, seem likely to be a good substitute for the first generation biofuels. The advanced biofuels are relatively costly to produce. This is due to the many steps in the production process, which restricts the usage of these sorts of fuels in the aviation industry. There are some problems associated with a jet fuel produced from 100% biomass. This is because the jet fuel produced from biomass differs from the jet fuels used today, making it unsafe to use in modern day airplane engines. That is why it is important to find an alternative jet fuel based on biomass that has the same characteristics as the conventional jet fuel, to be able to use the same transportation and engines that are in use today. Otherwise the high cost of advanced bio-jet fuels will make them unusable.
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King, Andrew James Campbell. "Thermal enhancement strategies for fluid jets impinging on a heated surface." Curtin University of Technology, Dept. of Mechanical Engineering, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17743.
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This research investigation examines the thermal behaviour of single and arrays of fluid jets impinging at heated surfaces, and formulates enhancement schemes for the jet impingement heat transfer processes for high-intensity cooling applications. The proposed techniques are numerically modelled and analysed over a wide parametric range to identify flow characteristics leading to thermal enhancement and optimum performance. The first scheme applies to a single fluid jet and incorporates a protruding object at the impingement surface to improve heat transfer. In this, a conical protrusion of high thermal conductivity is attached to the heated surface directly beneath the jet. Three different aspect ratios of 0.5, 1 and 2 are investigated for the protrusion while the inclusion of a fillet at the base of the cone is also studied. Jet Reynolds numbers between 100 and 30,000 are modelled. The observed thermal performance is compared with a reference case having no surface attachment. With this arrangement, the heat transfer rate typically varies between 10 and 40 percent above the reference case although depending on certain parametric combinations, the heat transfer may increase above or decrease below the reference performance. The highest indicated increase in heat transfer is about 90 percent while 15 percent below is the lowest. Careful selection of cone surface profile creates potential for further thermal enhancement.The second scheme applies to a single fluid jet and incorporates a recess in the impingement surface to improve heat transfer. In this, a cylindrical cavity is introduced to the surface beneath the jet into which the fluid jet impinges. The effects of the cavity on heat transfer are examined for a number of different cavity diameters, cavity depths and jet discharge heights wherein a surface without a cavity is taken as the reference surface. Cavity diameters of 2, 3 and 4 times the jet diameter are investigated at cavity depths between zero and 4 times the jet diameter. Jet discharge heights range between 2 jet diameters above the reference surface to 2 jet diameters below the reference surface. The jet Reynolds number is varied between 100 and 30,000. With this enhancement technique, increases in heat transfer rates of up to 45 percent are observed when compared to the reference performance. The thermal performance of fluid jet arrays is examined by altering square or hexagonal array configurations to identify flow characteristics leading to optimal heat transfer rates. For this, the jet to jet spacing is varied between 1.5 and 7 times the jet diameter while the jet to surface height is varied between 2 and 6 times the jet diameter. Jet Reynolds numbers between 100 and 30,000 are investigated. For each configuration, a critical jet-to-jet spacing is identified below which the heat transfer is observed to reduce significantly. Correlations for the expected heat transfer for a square or hexagonal array are presented in terms of the jet to jet spacing, jet height and jet Reynolds number.
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Munzar, Jeffrey. "Laminar flame speed of jet fuel surrogates and second generation biojet fuel blends." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116976.
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An understanding of the fundamental combustion properties of alternative fuels is essential for their adoption as replacements for non-renewable sources. In the aviation industry, a promising candidate is hydrotreated renewable jet fuel (HRJF). HRJF can be synthesized in a sustainable and economically viable manner from long chain fatty-acid methyl esters found in jatropha and camelina seed, and the laboratory-scale characterization of the combustion properties of HRJF is an active area of research. Such research is motivated, in part, by the chemical complexity of biojet fuels which are composed of hundreds of hydrocarbon species, similar to conventional aviation grade fuels. The laminar flame speed has been identified as an important combustion parameter for many combustion applications, and is especially relevant to the aviation community. The laminar flame speed is also an important parameter in the validation of chemical kinetic mechanisms, as it is representative of the chemical reactivity of the fuel. In this study, laminar, atmospheric pressure, premixed stagnation flames were used to determine the laminar flame speed of HRJF blended in varying ratios with Jet A-1 aviation fuel, requiring a combination of experimental and numerical methods. Jet A-1 was also studied to allow for comparative benchmarking of the biojet blends. Experiments were carried out in a jet-wall stagnation flame geometry at a pre-heated temperature of 400 K. Centerline velocity profiles were obtained using particle image velocimetry, from which the strained reference flame speeds were determined. Simulations of each experiment were carried out using the CHEMKIN-PRO software package together with a detailed chemical kinetic mechanism, with the specification of necessary boundary conditions taken entirely from experimental measurements. A direct comparison method was used to infer the true laminar flame speed from the experimental and numerical strained reference flame speeds. In order to model the chemical kinetics of Jet A-1 and the biojet blends, it was necessary to identify a surrogate blend that emulates the reactivity of the biojet fuels, while consisting of a much smaller number of pure compounds. Published data shows significant discrepancies for many jet fuel surrogate components, motivating their inclusion in this study. Thus, laminar flame speeds were also obtained for three candidate jet fuel surrogate components: n-decane, methylcyclohexane and toluene, which are representative of the alkane, cycloalkane and aromatic components of conventional aviation fuel, respectively. Results for the pure surrogate components were used to generate a suitable surrogate blend for the biojet blends. The results form this work resolve conflicting laminar flame speed data for the surrogate components, which is essential for the further development of chemical kinetic mechanisms and contributes to the surrogate modelling of jet fuel combustion. The laminar flame speeds of the biojet blends are compared to the Jet A-1 benchmark over a wide range of equivalence ratios. The biojet blends are found to behave similarly to Jet A-1 for low to moderate levels of blending, but show a marked disagreement otherwise.La comprehension des proprietes de combustion fondamentales des carburants alternatifs est essentielle pour leur adoption en remplacement des sources non renouvelables. Dans le secteur de l'aviation, un candidat encourageant est le carburant d'avion renouvelable hydrotraite (HRJF). HRJF peuvent etre synthetiser de maniere durable et economique en utilisant des esters methyliques a longue cha^ne procure de gras trouves dans les grains de jatropha et de cameline, et la caracterisation a l'echelle laboratoire des proprietes de combustion du HRJF est un domaine de recherche actif. Cette recherche est motivee, en partie, par la complexite chimique des combustibles d'avion biologiques qui sont composees de centaines d'especes d'hydrocarbures conventionnels, semblables a des combustibles d'aviation conventionnel. La vitesse de flamme laminaire a ete identie comme un parametre de combustion important pour de nombreuses applications de combustion, et est particulierement pertinent pour la communaute aeronautique. La vitesse de flamme laminaire est egalement un parametre important dans la validation des mecanismes de cinetiques chimiques, car il est representatif de la reactivite chimique du combustible. Dans cette etude, les flammes laminaire en stagnation, sous la pression atmospherique, et premelangees ont ete utilises pour determiner la vitesse de flamme laminaire de HRJF melanges dans des proportions variables avec du carburant de l'aviation Jet A-1, ce qui exigeait une combinaison de methodes experimentales et numeriques. Jet A-1 a egalement ete etudie pour permettre une analyse comparative des melanges de carburants. Des experiences ont ete menees dans une geometrie de vjet-mur flamme de stagnation a une temperature prechauee de 400 K. Des prols de vitesse centrales ont ete obtenus en utilisant la velocimetrie par image de particules, qui ont permit de determiner les vitesses de flammes de reference tendues. Simulations de chaque experience ont ete realisees en utilisant le logiciel CHEMKIN-PRO en conjunction avec un mecanisme chimique cinetique detaille, avec la specication de conditions aux limites necessaires prises entierement des mesures experimentales. Une methode de comparaison directe a ete utilisee pour deduire la vrai vitesse de flamme laminaire en utilisant les vitesses de flamme de reference tendues experimentales et numeriques. Pour modeliser la cinetique chimique du Jet A-1 et les melanges biologiques, il etait necessaire d'identier un melange de substitution qui emule la reactivite des carburants, tout en comprenant un nombre beaucoup plus restreint de combustibles purs. Les donnees publiees montrent des ecarts importants pour nombreux de ces composants de carburant de substitution, motivant leur inclusion dans cette etude. Ainsi, la vitesse de flamme laminaire a ete egalement obtenus pour trois candidats de composants substitutus pour la carburant d'aviation: n-decane, methylcyclohexane et toluene, qui sont representatifs des composants d'alcane, cycloalcane et aromatiques du carburant d'aviation conventionnel, respectivement. Les resultats pour les composants purs de substitution ont ete utilises pour generer un melange adequat de substitution pour les melanges de carburant biologiques. Les resultats de ce travail resout les conflits entre les donnees de vitesse de flamme laminaire pour les composants de substitution, qui est essentiel pour le developpement des mecanismes de cinetiques chimiques et contribue a la modelisation des carburants vide substitution de la combustion. Les vitesses de flamme laminaire des melanges de carburants biologiques sont comparees a Jet A-1 a dierents rapports d'equivalence. Les melanges biologiques comportent de facon similaire a Jet A-1 pour les niveaux de melange faible a modere, mais montrent un important ecart autrement.
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Kasprzak, Mary A. "Forecasting jet fuel prices using artificial neural networks." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1995. http://handle.dtic.mil/100.2/ADA294227.
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Kim, David Nylander-French Leena A. "Toxicokinetic models of dermal exposure to jet fuel." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2006. http://dc.lib.unc.edu/u?/etd,280.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2006.Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Environmental Sciences and Engineering." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.
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Tsimis, Charalampos. "Fuel jet injection and supersonic mixing for scramjets." Thesis, Imperial College London, 2007. http://hdl.handle.net/10044/1/8722.
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Parker, Grant Houston. "Pyrolytic Decomposition of Synthetic Paraffinic Kerosene Fuel Compared to JP-7 and JP-8 Aviation Fuels." University of Dayton / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1375319641.
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Berrigan, John Daniel. "Nanopowder nickel aluminate for benzothiophene adsorption from dodecane." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26580.
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Thesis (M. S.)--Materials Science and Engineering, Georgia Institute of Technology, 2009.Committee Chair: Carter, W.B.; Committee Member: Cochran, Joseph; Committee Member: Venugopal, Ganesh. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Kuhn, Stephen (Stephen Richard). "Cost-benefit analysis of ultra-low sulfur jet fuel." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59683.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 118-122).
The growth of aviation has spurred increased study of its environmental impacts and the possible mitigation thereof. One emissions reduction option is the introduction of an Ultra Low Sulfur (ULS) jet fuel standard for global commercial aviation. A full cost-benefit analysis, including impacts on air quality, climate, operations, and lifecycle costs is necessary to justify such a policy. The cost of a ULS jet fuel policy is well-characterized by the adoption of ULS diesel fuel, similar to jet fuel, for ground transportation in the US and elsewhere. The cost of hydrodesulfurization (HDS), the process used to remove sulfur from fuel, is projected to be between 4 and 7 cents per gallon of jet fuel. With 2006 levels of domestic fuel consumption, this translates to a yearly cost of HDS of $540-$940 million within the US. The climate and air quality benefits are characterized by several earth-atmosphere models, which isolate the perturbation of aviation emissions. Comparisons among models, which employ different modeling methods and assumptions as well as different spatial resolution, provide some cross-validation, as well as characterizing the degree of uncertainty in the state of the science. This thesis focuses in detail on the CMAQ (Community Multi-scale Air Quality) model, used by the Environmental Protection Agency (EPA) to support regulatory impact assessment. Other models, their results, and efforts at inter-model comparison are also discussed. Benefits are monetized through valuing the reduction in premature mortality from reduced concentrations of ground-level particulate matter (PM). The central finding from CMAQ is that with nominal health impact parameters, a global ULS jet fuel policy is predicted to save 110 lives per year in the US when considering full flight emissions, a 14% reduction in aviation-attributable mortality resulting in an estimated monetary benefit of $800 million.
by Stephen Kuhn.
S.M.
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Carter, Nicholas Aaron. "Environmental and economic assessment of microalgae-derived jet fuel." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76099.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 141-149).
Significant efforts must be undertaken to quantitatively assess various alternative jet fuel pathways when working towards achieving environmental and economic United States commercial and military alternative aviation fuel goals within the next decade. This thesis provides lifecycle assessments (LCAs) of the environmental and economic impacts of cultivating and harvesting phototrophic microalgae; extracting, transporting, and processing algal oils to hydrocarbon fuels; and distributing and combusting the processed renewable jet fuel for a pilot scale facility. Specifically, lifecycle greenhouse gas (GHG) emissions, production costs, freshwater consumption, and land use were quantified for four cultivation and two extraction technology sets. For each cultivation and extraction type, low, baseline, and high scenarios were used to assess the variability of each performance metric. Furthermore, sensitivity analyses were used to gain insights as to where efforts towards improving certain technologies could have the largest impact on improving the lifecycle metrics. The four cultivation technologies include open raceway ponds, horizontal serpentine tubular photobioreactors (PBRs), vertical serpentine tubular PBRs, and vertical flat panel PBRs. Open raceway ponds were modeled from previous literature, while the PBRs were modeled, validated and optimized for specific constraints and growth inputs. The algal oil extraction techniques include conventional dewatering, drying, and extraction using hexane in a similar process to seed oil extraction (termed dry extraction in this study) as well as algal cell lysing with steam and potassium hydroxide as well as fluid separation and washing processes (termed wet extraction). Overall, open raceway pond cultivation with wet extraction performed most favorably when compared with the other scenarios for GHG emissions, production costs, freshwater consumption, and areal productivity (including the entire cultivation and extraction facility), yielding 31.3 g-CO2e/MJHEFA-J, 0.078 $/MJHEFA-J (9.86 $/galHEFA-J), 0.38 Lfreshwater/MJHEFA-J and 17,600 LTAG/ha/yr for the baseline cases with brackish water makeup. The lifecycle GHG emissions and production cost metrics for the open raceway pond with wet extraction low scenario were both lower than that of conventional jet fuel baselines. For all cases, the inputs most sensitive to the lifecycle metrics were the cultivation system biomass areal productivity, algal extractable lipid weight fraction, and downstream harvesting system choices.
by Nicholas Aaron Carter.
S.M.
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Ferreira, Ana Rute Marques. "Mercaptans extraction from jet-fuel streams using ionic liquids." Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13663.
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Doutoramento em Engenharia da Refinação, Petroquímica e QuímicaDesulfurization is one of the most important processes in the refining industry. Due to a growing concern about the risks to human health and environment, associated with the emissions of sulfur compounds, legislation has become more stringent, requiring a drastic reduction in the sulfur content of fuel to levels close to zero (< 10 ppm S). However, conventional desulfurization processes are inefficient and have high operating costs. This scenario stimulates the improvement of existing processes and the development of new and more efficient technologies. Aiming at overcoming these shortcomings, this work investigates an alternative desulfurization process using ionic liquids for the removal of mercaptans from "jet fuel" streams. The screening and selection of the most suitable ionic liquid were performed based on experimental and COSMO-RS predicted liquid-liquid equilibrium data. A model feed of 1-hexanethiol and n-dodecane was selected to represent a jet-fuel stream. High selectivities were determined, as a result of the low mutual solubility between the ionic liquid and the hydrocarbon matrix, proving the potential use of the ionic liquid, which prevents the loss of fuel for the solvent. The distribution ratios of mercaptans towards the ionic liquids were not as favorable, making the traditional liquid-liquid extraction processes not suitable for the removal of aliphatic S-compounds due to the high volume of extractant required. This work explores alternative methods and proposes the use of ionic liquids in a separation process assisted by membranes. In the process proposed the ionic liquid is used as extracting solvent of the sulfur species, in a hollow fiber membrane contactor, without co-extracting the other jet-fuel compound. In a second contactor, the ionic liquid is regenerated applying a sweep gas stripping, which allows for its reuse in a closed loop between the two membrane contactors. This integrated extraction/regeneration process of desulfurization produced a jet-fuel model with sulfur content lower than 2 ppm of S, as envisaged by legislation for the use of ultra-low sulfur jet-fuel. This result confirms the high potential for development of ultra-deep desulfurization application.
A dessulfuração é um dos processos mais importantes na indústria da refinação. Devido a uma preocupação crescente com os riscos para a saúde humana e ambiente associados às emissões de compostos de enxofre, a legislação tem vindo a tornar-se mais rigorosa, exigindo uma redução drástica do teor de enxofre nos combustível para níveis próximos de zero (< 10 ppm S). No entanto, os processos convencionais de dessulfuração são ineficientes e apresentam custos operacionais elevados, o que tem impulsionado a melhoria dos processos existentes e o desenvolvimento de novas tecnologias com maior eficiência. Com o objetivo de colmatar as lacunas referidas, este projeto de doutoramento investiga um processo alternativo de dessulfuração com a utilização de líquidos iónicos para a remoção de mercaptanos de correntes de “jet-fuel”. A triagem e a seleção do líquido iónico mais adequado foram realizadas com base em dados experimentais e previstos, utilizando o modelo termodinâmico COSMO-RS, de equilíbrio líquido-líquido. Foi seleccionada uma alimentação modelo de 1-hexanotiol e n-dodecano para representar a corrente de “jet-fuel”. Foram observadas seletividades elevadas, como resultado da baixa solubilidade mútua entre o líquido iónico e o hidrocarboneto, o que demonstra o potencial de utilização dos líquido iónicos, uma vez que a contaminação e a perda do combustível para o solvente são evitadas. Os coeficientes de distribuição dos mercaptanos em relação aos líquidos iónicos são desfavoráveis, o que torna os processos tradicionais de extração líquido-líquido inadequados para a remoção de compostos alifáticos com enxofre, devido ao volume elevado de solvente que seria necessário utilizar. Este trabalho explora métodos alternativos e propõe a utilização dos líquidos iónicos num processo de separação assistido por membranas. No processo desenvolvido, o líquido iónico é utilizado como solvente na extracção do mercaptano da alimentação, realizada num contator de membrana de fibra oca, sem a co-extração do hidrocarboneto do “jet-fuel” modelo. Recorrendo a um segundo contator, o líquido iónico é regenerado através de uma corrente de gás de arraste, o que permite a sua reciclagem e reutilização em circuito fechado entre os dois contactores. Este processo integrado de extração/regeneração produziu um “jet-fuel” modelo com teor de enxofre inferior a 2 ppm, atingindo-se assim valores inferiores aos estabelecidos pela actual legislação. Demonstra-se assim que este processo tem um potencial de desenvolvimento elevado para aplicação em processos industriais de dessulfuração profunda.
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Bensel, Artur. "Characteristics of the Specific Fuel Consumption for Jet Engines." Aircraft Design and Systems Group (AERO), Department of Automotive and Aeronautical Engineering, Hamburg University of Applied Sciences, 2018. http://d-nb.info/1175791237.
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Purpose of this project is a) the evaluation of the Thrust Specific Fuel Consumption (TSFC) of jet engines in cruise as a function of flight altitude, speed and thrust and b) the determination of the optimum cruise speed for maximum range of jet airplanes based on TSFC characteristics from a). Related to a) a literature review shows different models for the influence of altitude and speed on TSFC. A simple model describing the influence of thrust on TSFC seems not to exist in the literature. Here, openly available data was collected and evaluated. TSFC versus thrust is described by the so-called bucket curve with lowest TSFC at the bucket point at a certain thrust setting. A new simple equation was devised approximating the influence of thrust on TSFC. It was found that the influence of thrust as well as of altitude on TSFC is small and can be neglected in cruise conditions in many cases. However, TSFC is roughly a linear function of speed. This follows already from first principles. Related to b) it was found that the academically taught optimum flight speed (1.316 times minimum drag speed) for maximum range of jet airplanes is inaccurate, because the derivation is based on the unrealistic assumption of TSFC being constant with speed. Taking account of the influence of speed on TSFC and on drag, the optimum flight speed is only about 1.05 to 1.11 the minimum drag speed depending on aircraft weight. The amount of actual engine data was extremely limited in this project and the results will, therefore, only be as accurate as the input data. Results may only have a limited universal validity, because only four jet engine types were analyzed. One of the project's original value is the new simple polynomial function to estimate variations in TSFC from variations in thrust while maintaining constant speed and altitude.
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Aftab, Mohammad Adnan. "Biofuel, An alternative source for jet fuel in Aviation." Thesis, Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-34914.
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The transport industry is one of the fastest growing industries with the sector playing a significant role in negative impact on global warming and pollution through the emission of greenhouse gases. Aviation in particular, has enjoyed growth especially in the few decades. New airlines and aircraft manufacturers are coming up with different innovations and technologies to ensure they make the best possible environmentally friendly aircraft. The new main area of focus has been on how to come up with fuel that will reduce the greenhouse gas-emissions. The stakeholders in the same effort include developed nations like the United States, United Kingdom, Russia, France, Germany, and Canada among others. Energy providers as well as jet fuel suppliers are also making efforts to conserve the environment. The purpose of this thesis is to explore the area of biofuel in aviation by looking into various stakeholders involved in the efforts of the transition from fossil fuel to biofuel. The conclusion of this thesis is that biofuels are viable options in the aviation industries since there have been positive results in the tests made.
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Reichel, Jonathan R. "Parametric study of liquid fuel jet in crossflow at conditions typical of aerospace applications." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22590.
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Abdul, Aziz M. M. "Liquid fuelled jet shear layer gas turbine combustion." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233835.
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Fishbein, Bryan. "Combustion of surrogate jet fuel components in premixed stagnation flames." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97224.
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The combustion of modern jet fuel, known as Jet A, in aero-derived gas turbine engines is a complicated process that is not fully understood. While many attempts have been made to produce numerical and chemical models of Jet A, the current lack of consensus within literature suggests that more work remains. This work will study three pure substances, which are representative of the chemical components that comprise typical jet fuels. n-Decane represents the alkanes present in Jet A, methylcyclohexane the cyclic hydrocarbons, and toluene the aromatics. All three compounds are used to stabilize flames in a stagnation flow burner, with their velocity profiles measured using particle image velocimetry. These velocity profiles are then compared so that the relative reactivity of these three compounds can be established. It was found that the most reactive substance was n-decane, followed by methylcyclohexane, with toluene being the least reactive. In addition, the predictions of an analytical hydrodynamic model are compared to experimental results. The analytical model was found to be in good agreement under stoichiometric and fuel rich conditions, but diverges as the flames become increasingly fuel lean. This result can be explained either by issues which remain in the experimental apparatus, or by inaccuracies within data collected from literature, and this warrants further investigation. The experience gained in assembling the apparatus will be used to continue its development to facilitate future studies.La combustion du carburant d'aviation, connu sous le nom de Jet A, dans les turbines à gaz aro-drives est un processus complexe qui n'est pas entièrement compris. Bien que de nombreuse études on été faites pour produire des modèles num ́eriques et chimiques du Jet A, l'absence de consensus dans la littérature montre qu'il reste encore du travail. Ce travail est une étude de trois substances pures, qui sont représentatifs de la composition chimique qui constituent les carburants d'aviation. Le n-décane représente les alcanes présents dans le Jet A, le méthylcyclohexane les hydrocarbures cycliques, et le toluène les aromatiques. Les trois composés sont utilisés pour stabiliser les flammes dans un brûleur à écoulement stagné, avec les profils de vitesse mesurés à l'aide de la technique de vélocimétrie par images de particules. Ces profils de vitesse sont ensuite comparés de telle sorte que la réactivité relative de ces trois composés peut être déduite. Il a été constat que la substance la plus réactive est le n-décane, suivie par le méthylcyclohexane et le toluène étant le moins réactif. Aussi, les prédictions d'un modèle analytique hydrodynamique sont comparèes aux résultats expérimentaux. Le modèle analytique a donné un bon accord sous les conditions stœchiomtrique et riche mais diverge dans les conditions de flammes pauvres. Ce résultat peut s'expliquer soit par des problèmes qui restent dans le dispositif expérimental, ou par l'inexactitude des données collectées dans la littérature, ce qui justifie plus d'investigations. L'expérience acquise dans le montage de l'appareil sera utilisé pour continuer son développement afin de faciliter les études futures.
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Denman, Bradley. "Flame propagation of jet A-1 fuel and its surrogates." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=116958.
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The laminar flame speed is an essential flame parameter for both chemical kinetic mechanism validation and turbulent combustion studies. Kerosene-derived jet fuel flame speeds, however, are largely unknown and due to complex composition of the fuels themselves they cannot be modelled numerically. To overcome this limitation surrogate fuels and blends are used to reproduce the same flame speed of amore complex mixture. To accomplish this for aviation fuel, a database is created of four potential jet fuel surrogate components for laminar flame speed. The neat hydrocarbon surrogates investigated are n-dodecane and n-decane, methylcyclohex-ane, and toluene, which represent the alkane, cycloalkane, and aromatic components of conventional aviation fuel, respectively. Several blends of these surrogate fuels are tested experimentally and numerically to validate the effect of blend composition on flame speed. The database is then used to develop a blend to match the flame speeds of a commercial aviation fuel, Jet A-1. Unlike previous investigations of flame propagation, in this study, numerical simulations are directly compared to velocity profile measurements in laminar stagnation flames to extrapolate to a condition of zero flame stretch. Numerical simulations of each experiment are obtained using the CHEMKIN-PRO software package and the JetSurF 2.0 mechanism with accurate specification of all necessary boundary conditions from experimental measurements. The advantage of this technique is that the extrapolation to the unstretched condition is independent of the how well the mechanism predicts reactivity. Therefore, JetSurF 2.0 was simultaneously validated for each of the surrogate fuels and blends in a previously unused manner. The mechanism showed relatively good agreement for the n-alkane and cycloalkane fuels for which it was optimized for, while consistently under predicted the reactivity of toluene. The compiled database of jet fuel surrogate components allowed for five different potential surrogate mixtures to be developed. Experimental results of these blends suggest that although jet fuel is a very complex mixture a simple surrogate mixture consisting of 73% n-decane and 27% toluene byvolume appropriately matches the flame speed of Jet A-1. Numerical results using JetSurF 2.0 suggest that a 63% n-decane and 37% toluene by volume blend is the most appropriate surrogate and this was used to extrapolate the experimental JetA-1 results and determine its laminar flame speed.La vitesse laminaire de flamme est un paramètre essentiel, autant pour la validation de mécanismes de cinétique chimique de flamme, que pour l'étude de la combustion turbulente. Toutefois, les vitesses de flamme des carburants d'aviations, dérivés du kérosène, sont en grande partie inconnues, et, en raison de leur composition complexe, ces carburants ne peuvent être modélisés numériquement. Pour surmonter cette lacune, des combustibles de substitution et des mélanges sont utilisés pour reproduire la vitesse de flamme d'un mélange plus complexe. Pour accomplir cela pour le carburant d'aviation, une base de données pour la vitesse de flamme laminaire est créée partir de quatre composants de substitution potentiels. Les hydrocarbures de substitution étudiés sont le n-dodécane et le n-décane, le méthylcyclohexane, et le toluène, qui représentent l'alcane, le cycloalcane, et les composants aromatiques du carburant d'aviation conventionnel, respectivement. Plusieurs mélanges de carburants de substitution sont testés expérimentalement et numériquement pour valider l'effet de la composition du mélange sur la vitesse de flamme. La base de données est ensuite utilisée pour élaborer un mélange ayant des vitesses de flamme correspondant au carburant commercial d'aviation Jet A-1. Contrairement aux études précédentes sur la propagation des flammes, dans la présente étude, des simulations numériques sont compaées directement des mesures de profil de vitesse de flammes laminaires de stagnation, afin d'extrapoler les résultats une condition de zéro étirement de la flamme. Les simulations numériques pour chaque expérience sont obtenues en utilisant le logiciel CHEMKIN-PRO et le mécanisme de cinétique JetSurF 2.0, en spécifiant précisément toutes les conditions limites partir des mesures expérimentales. L'avantage de cette technique est que l'extrapolation l'état non étiré est indépendante de la prédiction de réactivité inhérente au mécanisme utilisé. Par conséquent, JetSurF 2.0 était simultanément validé pour chacun des carburants de substitution et chacun des mélanges en utilisant cette mréthode innovatrice. Le mrécanisme a montrré une concordance relativement bonne pour les carburants n-alcanes et cycloalcanes, pour lesquels il a étré optimisé, tandis quil a constamment sous-prédit la réactivité du toluène. La base de données compilée pour les composants de substitution du carburant daviation a permis de développer cinq différents mélanges de substituts potentiels. Les résultats expérimentaux de ces mélanges suggèrent que, bien que le kérosène soit un mélange très complexe, un simple mrélange composé 73% de n-décane et 27% de toluène, en volume, reproduit la vitesse de flamme du Jet A-1 de manière appropriée. Les résultats numériques utilisant JetSurF 2,0 suggèrent que de 63% n-décane et 37% de toluène par un mrélange de volume est le substitut le plus approprié et cela a été utilisé pour extrapoler le Jet A-1 expérimentale des résultats et de déterminer sa vitesse de flamme laminaire.
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Rawson, Paul Stansfield Christy-Anne. "Field method for detection of metal deactivator additive in jet fuel." Fishermans Bend, Victoria : Defence Science and Technology Organisation, 2009. http://nla.gov.au/nla.arc-24592.
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Andersson, Sanna, and Erica Edfeldt. "Lönsamhetsanalys för svenskproducerat biojetbränsle baserad på alger." Thesis, KTH, Energiteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-41498.
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Dagens transportsektor är beroende utav fossila drivmedel. Detta är problematiskt eftersom fossila bränslen är en ändlig resurs samtidigt som användningen utav dessa bidrar till den förstärkta växthuseffekten. Enligt EU:s klimatmål ska utsläppen av växthusgaser reduceras med 20 procent till år 2020. Handeln med utsläppsrätter, som flygsektorn inkluderas i från och med år 2012, har införts som ett styrmedel som skall verka för att företag ska minska sina utsläpp. Flygföretag kommer härigenom att ha ökade incitament att blanda in en viss procenthalt biojetbränsle i det fossila jetbränslet. Mycket forskning och utveckling pågår kring framtagandet av andra generationens biodrivmedel, till vilka algbaserat biodrivmedel räknas. Algbaserat biodrivmedel tros ha god framtidspotential då alger kan odlas på mark som ej är lämplig för matodling, har en hög tillväxttakt, högt oljeinnehåll samt förmågan att ta upp koldioxid från sin omgivning. Syftet med denna rapport var därmed att skapa en bred bild kring möjligheterna att med ekonomisk vinning producera algbaserat biodrivmedel för flyg i Sverige, vilken kan ligga till grund för vidare forskning på området. Målet var att utföra en lönsamhetsanalys för en produktionsprocess med lämpligt vald odlingsanläggning, algart, skördeteknik, vattenavskiljningsteknik samt teknik för vidare förädlingsprocesser. Detta efter att marknaden först, med hjälp av Porters femkraftsmodell, hade bedömts som lämplig att gå in på. Valen fattades med utgångspunkt i en litteraturstudie baserad på intervjuer, faktasökning i rapportdatabaser och i sökmotorer på Internet samt ett studiebesök på Käppala reningsverk. Valen kring produktionsanläggningen samt projektets uppskattade kostnader och intäkter motiverades i en fallstudie som sedan låg till grund för modellen. I modellen beräknades ett konkurrenskraftigt pris på biojetbränsle utifrån kostnaden för fossilt jetbränsle plus detta fossilbränsles relaterade utsläppsrättskostnad vid år 2020. Utifrån modellens huvudscenario uppskattades på så vis det konkurrenskraftiga priset år 2020 till 7,2 kronor per liter. För odling valdes öppna raceway-dammar i anslutning till ett reningsverk där det finns fri tillgång på näringsämnen och koldioxid. Algarten Chlorella Vulgaris valdes då den lämpar sig väl för denna odlingsanläggning. Produktionen beräknades uppnå en volym av 60 400 liter färdigt biojetbränsle per odlingssäsong (juni till september). Den årliga intäkten för huvudscenariot blev 455 100 kronor per år, medräknat det reningsverket antas betala för den koldioxidminskning algodlingen medför. Genom att alternera råoljepriset och utsläppsrättspriset togs fyra grundscenarion fram. Det utgicks ifrån att anläggningen tas i bruk år 2017 och en resultaträkning för en sjuårsperiod utfördes utifrån den årliga intäkten, framräknad grundinvestering och framräknade driftskostnader. Det årliga resultatet visade sig vara negativt eller strax över noll för samtliga fyra scenarion samt för huvudscenariot. Först vid ett försäljningspris på 10,8 kronor per liter blev projektet lönsamt med ett positivt nuvärde beräknat på sju år och en internränta på 15 procent. Återbetalningstiden beräknades till max fyra år. Huruvida ett premiumpris på 10,8 kronor per liter, flera kronor högre än det som ansågs vara konkurrenskraftigt, är möjligt att ta betalt för det algbaserade biojetbränslet är osäkert. Utifrån uppskattad kostnads- och intäktsbild är dock detta ett måste för att produktionen skall vara lönsam. I annat fall krävs externa förändringar såsom exempelvis kraftigt höjda råoljepriser, forskningsframsteg och effektiviseringar för framställningen av algbiodrivmedel eller att ytterligare politiska styrmedel gynnar biodrivmedel. Miljökostnader och miljövinster med en algbaserad biodrivmedelsproduktion samt förslag på ytterligare effektivisering av produktionen är vidare forskningsområden som denna rapport ämnar ligga till grund för.Today’s transportation sector is in a path dependency of the using of fossil fuel. This is problematic since there are limited oil sources in the world and since the use of fossil fuels increases the green house effects. According to EU’s climate goals the emissions of green house gases should be reduced by 20 percent by year 2020. The European emission trading system, which the airline industry will be a part of from 2012, raises the incentives for companies to lower their emissions. Airline companies will therefore be more likely to add a certain percentage of biofuels into their aircraft engines. A lot of research and development is currently being made about the second generation of biofuel. One raw material for a second generation biofuel is algae, which is believed to have great potential due to the fact that it can be cultured on marginal land, fast growth rate, high oil content and consumes carbon dioxide while growing. The aim with this report was to create a picture of the opportunities in Sweden to economically feasible produce algae biofuel for aircraft, from which continuous research can be made. The goal was to create an evaluation of whether it is profitable or not to have a production with carefully chosen growth facility, algae specie, harvest method, drying method and other refining steps. The market was first evaluated and found to be attractive, using the model of Porter’s five forces. Different decisions regarding the production was made based on interviews, information found in report databases and search engines online and based on the study visit at Käppala wastewater treatment plant. These decisions and the costs they are associated with were later used in the model. A competitive bio jet fuel price year 2020 is regarded to be the price on fossil jet fuel plus the cost for the related certificate of emission cost. In the model’s main scenario the competitive liter price year 2020 was calculated to be 7.2 Swedish kronor. The growth facility was designed as an open raceway pond integrated in a wastewater treatment plant, since the wastewater contains nutrition and carbon dioxide used in the algae photosynthesis. The algae specie chosen was Chlorella Vulgaris. The production will run every year from June to September and the produced volume is estimated 60 400 liters of bio jet fuel each production season. The yearly sales in the main scenario, including the money the wastewater treatment is paying for lowered carbon dioxide emissions, are estimated at 455 100 Swedish kronor. By altering the price of fossil fuel and of emission trading certificates four different scenarios were created. The production will begin in 2017 and the result was calculated for the first seven years based on the yearly income and the estimated start-up costs and running costs. The result turned out to be negative or just above zero for all four scenarios. The project was profitable at the price 10.8 Swedish kronor per liter with a positive net current value over seven years and internal rate of return at 15 percent. The payback time was calculated to be four years at the most. Whether or not it is possible to charge 10.8 Swedish kronor per liter is not certain. However, this is the price needed in order for the project to be profitable. Otherwise external changes are needed such as increased raw oil prices, successful research and development in the field of algae bio fuel production or increased political incentives in favor of bio fuels. Environmental costs and environmental gains with an algae fuel production as well as proposals for further efficiency are suggestions on further work that need to be done on this field.
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Balagurunathan, Jayakishan. "Investigation of Ignition Delay Times of Conventional (JP-8) and Synthetic (S-8) Jet Fuels: A Shock Tube Study." University of Dayton / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1330351552.
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Kurman, Matthew S. Cernansky N. P. Miller David L. "The preignition oxidation chemistry of n-decane and n-dodecane in a pressurized flow reactor and their use as jet fuel surrogate components /." Philadelphia, Pa. : Drexel University, 2010. http://hdl.handle.net/1860/3256.
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Dulbecco, Alessio. "Modeling of Diesel HCCI combustion and its impact on pollutant emissions applied to global engine system simulation." Thesis, Toulouse, INPT, 2010. http://www.theses.fr/2010INPT0015/document.
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La législation sur les émissions de polluants des Moteurs à Combustion Interne (ICEs) est de plus en plus contraignante et représente un gros défi pour les constructeurs automobiles. De nouvelles stratégies de combustion telles que la Combustion à Allumage par Compression Homogène (HCCI) et l’exploitation de stratégies d’injections multiples sont des voies prometteuses qui permettent de respecter les normes sur les émissions de NOx et de suies, du fait que la combustion a lieu dans un mélange très dilué et par conséquent à basse température. Ces aspects demandent la création d’outils numériques adaptés à ces nouveaux défis. Cette thèse présente le développement d’un nouveau modèle 0D de combustion Diesel HCCI : le dual Combustion Model (dual - CM). Le modèle dual-CM a été basé sur l’approche PCM-FPI utilisée en Mécanique des Fluides Numérique (CFD) 3D, qui permet de prédire les caractéristiques de l’auto-allumage et du dégagement de chaleur de tous les modes de combustion Diesel. Afin d’adapter l’approche PCM-FPI à un formalisme 0D, il est fondamental de décrire précisément le mélange à l’intérieur du cylindre. Par consequent, des modèles d’évaporation du carburant liquide, de formation de la zone de mélange et de variance de la fraction de mélange, qui permettent d’avoir une description détaillée des proprietés thermochimiques locales du mélange y compris pour des configurations adoptant des stratégies d’injections multiples, sont proposés. Dans une première phase, les résultats du modèle ont été comparés aux résultats du modèle 3D. Ensuite, le modèle dual-CM a été validé sur une grande base de données expérimentales; compte tenu du bon accord avec l’expérience et du temps de calcul réduit, l’approche présentée s’est montrée prometteuse pour des applications de type simulation système. Pour conclure, les limites des hypothèses utilisées dans dual-CM ont été investiguées et des perspectives pour les dévélopements futurs ont été proposéesMore and more stringent restrictions concerning the pollutant emissions of Internal Combustion Engines (ICEs) constitute a major challenge for the automotive industry. New combustion strategies such as Homogeneous Charge Compression Ignition (HCCI) and the implementation of complex injection strategies are promising solutions for achieving the imposed emission standards as they permit low NOx and soot emissions, via lean and highly diluted combustions, thus assuring low combustion temperatures. This requires the creation of numerical tools adapted to these new challenges. This Ph.D presents the development of a new 0D Diesel HCCI combustion model : the dual Combustion Model (dual−CM ). The dual-CM is based on the PCM-FPI approach used in 3D CFD, which allows to predict the characteristics of Auto-Ignition and Heat Release for all Diesel combustion modes. In order to adapt the PCM-FPI approach to a 0D formalism, a good description of the in-cylinder mixture is fundamental. Consequently, adapted models for liquid fuel evaporation, mixing zone formation and mixture fraction variance, which allow to have a detailed description of the local thermochemical properties of the mixture even in configurations adopting multiple injection strategies, are proposed. The results of the 0D model are compared in an initial step to the 3D CFD results. Then, the dual-CM is validated against a large experimental database; considering the good agreement with the experiments and low CPU costs, the presented approach is shown to be promising for global engine system simulations. Finally, the limits of the hypotheses made in the dual-CM are investigated and perspectives for future developments are proposed
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Xu, Xinhai. "Desulfurization and Autothermal Reforming of Jet-A Fuel to Produce Syngas for Onboard Solid Oxide Fuel Cell Applications." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/325215.
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Fuel cell is one of the most promising clean energy and alternative energy technologies due to its advantages of low emissions and high efficiency. One application of the fuel cell technology is onboard auxiliary power units (APUs) for power generation in aircrafts, ships, and automobiles. In order to supply hydrogen or syngas for the fuel cell APUs, onboard fuel processing technology was proposed to convert hydrocarbon fuels into syngas through reforming reactions. Two major tasks need to be completed in onboard fuel processing technology. Firstly sulfur compounds have to be removed from hydrocarbon fuels because sulfur can cause reforming catalyst deactivation and fuel cell electrodes poisoning problems. Secondly hydrogen and carbon monoxide shall be produced by reforming of hydrocarbon fuels at a high energy conversion efficiency. This dissertation focused on onboard fuel processing of Jet-A fuel to produce hydrogen and syngas for solid oxide fuel cell (SOFC) APUs. Jet-A fuel was studied because it is the logistic fuel commonly used for civilian airplanes and military heavy duty trucks. Ultra-deep adsorptive desulfurization of Jet-A fuel from over 1,000 ppmw to below 50 ppmw, and autothermal reforming of n-dodecane as a Jet-A fuel surrogate as well as the real desulfurized Jet-A fuel to produce syngas have been systematically investigated in the present study. For the adsorptive desulfurization of Jet-A fuel, a novel NiO-CeO₂/A1₂O₃-SiO₂ adsorbent was proposed and prepared in-house for experimental tests. The sulfur adsorption kinetic characteristic and isotherm at equilibrium were studied in batch tests, and the dynamic desulfurization performance of the adsorbent was investigated in fixed bed tests. Fixed bed tests operation conditions including liquid hourly space velocity (LHSV), adsorbent particle size, and fixed bed dimensions were optimized to achieve the highest adsorbent sulfur adsorption capacity. For the reforming of Jet-A fuel, autothermal reforming (ATR) method was employed and a bimetallic NiO-Rh catalyst was synthesized for the ATR reactions. A lab-scale 2.5 kWt autothermal reforming system including the reformer and balance-of-plant was designed, fabricated, integrated and tested. The reforming system performances at various operation conditions were compared. Reformer operation temperature, steam to carbon ratio and oxygen to carbon ratio, as well as pre-heating temperatures for fuel, air and steam were optimized based on system energy conversion efficiency, H₂ selectivity and COₓ selectivity.
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YAMASHITA, Hiroshi. "Numerical Study on NOx Production of Transitional Fuel Jet Diffusion Flame." The Japan Society of Mechanical Engineers, 2000. http://hdl.handle.net/2237/8999.
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Robledo, Raymond F. 1968. "Pulmonary response to inhaled jet-propulsion fuel 8 aerosol in mice." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/288888.
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Studies were initiated to characterize the acute and sub-chronic pulmonary responses to inhaled Jet-Propulsion Fuel 8 (JP-8) aerosol. At 24 to 30 hours following JP-8 exposure, physiological, biochemical, cellular, and morphological techniques were used to assay for lung injury. In addition, C57BL/6 and B6.A.D.(Ahyd mice were utilized in the acute study to determine if responsiveness to aryl hydrocarbon hydroxylase (AHH) induction modulates toxicity. JP-8 contains aromatic compounds that are known substrates for AHH. Acute lung injury was evident by increased respiratory permeability that was accompanied by alveolar macrophage infiltration and activation, following exposure to occupational permissible levels of JP-8. Morphological alterations were characterized by terminal bronchiolar lesions of vacuolization and necrosis. AHH responsiveness did not appear to influence the severity of JP-8 induced lung injury. Lung injury following sub-chronic inhalation was found to be progressive in nature. Repeated exposure induced alveolar hemorrhage and alveolar macrophage cytotoxicity. Morphological changes progressed to include epithelial denudation of bronchiolar airways and vacuolization of alveolar type II epithelial cells and adjacent endothelia. The pulmonary clearance of JP-8 following inhalation exposures was determined indirectly by analysis for tetradecane content within lung homogenates from exposed mice. Clearance of JP-8 following acute exposure was determined to have a half-life of 43 minutes and increased by 14 minutes following a toxic sub-chronic exposure. The relatively rapid pulmonary clearance of JP-8 following either acute or sub-chronic exposure implies that JP-8 induced lung injury was independent of pulmonary retention. Studies were also performed to determine if non-cytotoxic concentrations of JP-8 or tetradecane could decrease bronchial epithelial barrier function. Studies showed that one hour of exposure to JP-8 or tetradecane could significantly enhance paracellular permeability to mannitol in the BEAS-2B human bronchial epithelial cell line, at two hours after exposure. Bronchial epithelial permeability appeared to be more sensitive to tetradecane than JP-8. Subsequent recovery studies determined that JP-8 and tetradecane-induced decreases in barrier function reach a maximum at 12 hours and barrier function returns to control by 48 hours post-exposure. These results indicate that JP-8 induced lung injury may be initiated by changes in airway barrier function.
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Bann, Seamus J. "A stochastic techno-economic comparison of alternative jet fuel production pathways." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111238.
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Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, School of Engineering, Institute for Data, Systems, and Society, Technology and Policy Program, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references.
Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2017
This study quantifies and compares the costs of production for six alternative jet fuel pathways using consistent financial and technical assumptions. Uncertainty was propagated through the analysis using Monte Carlo simulations. The six processes assessed were hydroprocessed ester and fatty acids (HEFA) using soybean oil, yellow grease, and tallow; advanced fermentation (AF) using corn grain, sugarcane, and herbaceous biomass; conventional gasification and Fischer-Tropsch (FT) using municipal solid waste; aqueous phase processing (APP) using woody biomass; hydrothermal liquefaction (HTL) using woody biomass; and fast pyrolysis and hydroprocessing (FPH) using corn stover. The results indicate that none of the six processes would be profitable in the absence of government incentives, with HEFA using yellow grease, HEFA using tallow, and FT revealing the lowest mean jet fuel prices at $0.91/liter ($0.66/liter to $1.24/liter), $1.06/liter ($0.79/liter to $1.42/liter), and $1.15/liter ($0.95/liter to $1.39/liter), respectively. The highest mean NPV was the NPV calculated for HEFA yellow grease with a mean value (in $B) of -0.112 (95% range of -0.412 to 0.179), followed by HEFA tallow with -0.202 (-0.517 to 0.100) and FT with -0.210 (-0.424 to 0.033). This study also quantifies plant performance in the United States with a policy analysis. The alternative fuel production models were used to examine the economic viability of each pathway under a variety of existing and potential regulatory scenarios. Results indicate that some pathways could achieve positive NPV with relatively high likelihood under existing policy supports, with HEFA and FPH revealing the highest probability of positive NPV at 94.9% and 99.7%, respectively, in the best-case scenario.
by Seamus J. Bann.
S.M. in Technology and Policy
S.M.
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Deshpande, Kshitij S. "FUEL FLOW CONTROL ISSUE IN JET ENGINES: AN EVOLVABLE HARDWARE APPROACH." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1197669660.
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Erete, James Ikpeme. "Aerodynamic and fuel dilution effects on non-premixed gas jet flames." Thesis, University of Leeds, 2015. http://etheses.whiterose.ac.uk/11491/.
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This study examines the changes in the flame structure and emissions from laboratory-scale flares over a wide range of test conditions. In the initial study, the experimental measurements examined the effect of varying the fuel jet velocity on the flame temperature, flame structure, and the inflame and post-flame composition of species in methane flames. The test conditions involved laboratory-scale flares in the attached and lifted regimes under laminar, transitional and turbulent conditions. The results show that while an increase in the jet velocity leads to an increase in EINOx, this also leads to a decrease in EICO, and similarly, EICO decreases with decreasing flame luminosity and sooting propensity. The second study examined the effect of CO2 dilution on methane jet flames where CO2, which was used as a diluent, was injected into the fuel-jet stream. The dilution-induced extinction was achieved by fixing the fuel flow rate, while varying the diluent mole fraction. The effect of the changes in the flame length, lift-off height, and in the emissions due to this dilution was studied. Amongst other findings, this study shows that CO2 is effective in reducing the EINOx in the postflame region of methane jet flames at Reynolds number ranging from 1584 to 14254, and that soot formation is suppressed at higher diluent concentrations in the jet flame. The final study involved the characterisation and the comparison of the inflame composition of major species and the post-flame soot and pollutant emissions generated from the combustion of methane and propane flames. The results show that the dilution of the fuel stream with CO2 reduces the size of soot aggregates in propane flames and that the soot emission factor decreases at increased diluent concentrations. In addition, for the same test conditions utilised in this study, the EICO and EINOx are higher in methane flames than in propane flames.
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Chen, Rui. "Fluidic devices as fuel injectors for natural gas engines." Thesis, Loughborough University, 1997. https://dspace.lboro.ac.uk/2134/13566.
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A novel, fast switching, reliable, and economical fluidic gaseous fuel injector system designed for natural gas engines has been developed in this research. The system consists mainly of no-moving-part fluidic devices and piezo-electric controlling interfaces. The geometric parameters of a fluidic device seriously affect its performance. Traditionally, these parameters can only be optimised through "trial and error" exercise. In this research, a computer simulation model for the jet steady state attachment and dynamic switching has been developed. The good agreements between predicted results and experimental ones show that the model can not only explain the jet attaching and switching mechanism, but also optimise the design of geometric parameters of a fluidic device. The steady state and dynamic characteristics of the system were tested on a laboratory experimental rig. The results show that the system can handle the large gas volume flow rate required by natural gas engines and is capable of operating via pulse width modulation. A few typical commercial solenoid type gas injectors were also tested and the results were compared with those from the fluidic system. It was found that the fluidic gaseous fuel injector system has faster switching responses and smaller injection cycle-to-cycle variations.
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Gardner, Paul. "Aerosol Jet Printing of LSCF-CGO Cathode for Solid Oxide Fuel Cells." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1316166020.
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Sjölander, Johan. "Production and harvesting of volatile jet fuel precursors from Synechocystis sp. PCC 6803." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-397851.
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The world is currently faced with the enormous challenge of slowing down human triggered global warming. As the global energy demand increases, there is an urgent need for renewable and carbon-neutral fuel-sources. Isoprene and isobutene are crude-oil derived, short, volatile and reactive hydrocarbons that can be polymerised into longer chains to be used as jet fuel. Isoprene has previously been produced from the cyanobacterial strain Synechocystis sp. PCC 6803 but there has been no reported isobutene synthesis from any photosynthetic organism. This work aimed to synthesise isobutene in Synechocystis using a cytochrome P450 from Cystobasidium minutum with reported isobutene production capability. Substrate availability was to be provided through the insertion of two heterologous enzymes, IpdC from Salmonella typhimurium and PadA from Escherichia coli. Both IpdC and PadA were successfully expressed in Synechocystis but the functional activities of IpdC, PadA and the cytochrome P450 in Synechocystis remains undetermined. This project also had the aim to design and construct a photo-bioreactor and gas collection system capable of producing and harvesting isoprene directly from an engineered Synechocystis strain. Herein lies a description of a closed system photobioreactor connected to a cold-trap that was able to concentrate isoprene produced from Synechocystis to measurable amounts.
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Wu, Ning. "Autoignition and emission characteristics of gaseous fuel direct-injection compression-ignition combustion." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/357.
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Heavy-duty natural gas engines offer air pollution and energy diversity benefits. However, current homogeneous-charge lean-burn engines suffer from impaired efficiency and high unburned fuel emissions. Natural gas direct-injection engines offer the potential of diesel-like efficiencies, but require further research. To improve understanding of the autoignition and emission characteristics of natural gas direct-injection compression-ignition combustion, the effects of key operating parameters (including injection pressure, injection duration, and pre-combustion temperature) and gaseous fuel composition(including the effects of ethane, hydrogen and nitrogen addition) were studied.
An experimental investigation was carried out on a shock tube facility. Ignition delay, ignition kernel location, and NOx emissions were measured. The results indicated that the addition of ethane to the fuel resulted in a decrease in ignition delay and a significant increase in NOx emissions. The addition of hydrogen to the fuel resulted in a decrease in ignition delay and a significant decrease in NOx emissions. Diluting the fuel with nitrogen resulted in an increase in ignition delay and a significant decrease in NOx emissions. Increasing pre-combustion temperature resulted in a significant reduction in ignition delay, and a significant increase in NOx emissions. Modest increase in injection pressure reduced the ignition delay; increasing injection pressure resulted in higher NOx emissions. The effects of ethane, hydrogen, and nitrogen addition on the ignition delay of methane were also successfully predicted by FlameMaster simulation.
OH radical distribution in the flame was visualized utilizing Planar Laser Induced Fluorescence (PLIF). Single-shot OH-PLIF images revealed the stochastic nature of the autoignition process of non-premixed methane jets. Examination of the convergence of the ensemble-averaged OH-PLIF images showed that increasing the number of repeat experiments was the most effective way to achieve a more converged result.
A combustion model, which incorporated the Conditional Source-term Estimation(CSE) method for the closure of the chemical source term and the Trajectory Generated Low-Dimensional Manifold (TGLDM) method for the reduction of detailed chemistry, was applied to predict the OH distribution in a combusting non-premixed methane jet. The model failed to predict the OH distribution as indicated by the ensemble-averaged OH-PLIF images, since it cannot account for fluctuations in either turbulence or chemistry.