Дисертації з теми "Automotive combustion and fuel engineering"
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Hockett, Andrew. "A computational and experimental study on combustion processes in natural gas/diesel dual fuel engines." Thesis, Colorado State University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=3746141.
Повний текст джерелаNatural gas/diesel dual fuel engines offer a path towards meeting current and future emissions standards with lower fuel cost. However, numerous technical challenges remain that require a greater understanding of the in-cylinder combustion physics. For example, due to the high compression ratio of diesel engines, substitution of natural gas for diesel fuel at high load is often limited by engine knock and pre-ignition. Additionally, increasing the natural gas percentage in a dual fuel engine often results in decreasing maximum load. These problems limit the substitution percentage of natural gas in high compression ratio diesel engines and therefore reduce the fuel cost savings. Furthermore, when operating at part load dual fuel engines can suffer from excessive emissions of unburned natural gas. Computational fluid dynamics (CFD) is a multi-dimensional modeling tool that can provide new information about the in-cylinder combustion processes causing these issues.
In this work a multi-dimensional CFD model has been developed for dual fuel natural gas/diesel combustion and validated across a wide range of engine loads, natural gas substitution percentages, and natural gas compositions. The model utilizes reduced chemical kinetics and a RANS based turbulence model. A new reduced chemical kinetic mechanism consisting of 141 species and 709 reactions was generated from multiple detailed mechanisms, and has been validated against ignition delay, laminar flame speed, diesel spray experiments, and dual fuel engine experiments using two different natural gas compositions. Engine experiments were conducted using a GM 1.9 liter turbocharged 4-cylinder common rail diesel engine, which was modified to accommodate port injection of natural gas and propane. A combination of experiments and simulations were used to explore the performance limitations of the light duty dual fuel engine including natural gas substitution percentage limits due to fast combustion or engine knock, pre-ignition, emissions, and maximum load. In particular, comparisons between detailed computations and experimental engine data resulted in an explanation of combustion phenomena leading to engine knock in dual fuel engines.
In addition to conventional dual fuel operation, a low temperature combustion strategy known as reactivity controlled compression ignition (RCCI) was explored using experiments and computations. RCCI uses early diesel injection to create a reactivity gradient leading to staged auto-ignition from the highest reactivity region to the lowest. Natural gas/diesel RCCI has proven to yield high efficiency and low emissions at moderate load, but has not been realized at the high loads possible in conventional diesel engines. Previous attempts to model natural gas/diesel RCCI using a RANS based turbulence model and a single component diesel fuel surrogate have shown much larger combustion rates than seen in experimental heat release rate profiles, because the reactivity gradient of real diesel fuel is not well captured. To obtain better agreement with experiments, a reduced dual fuel mechanism was constructed using a two component diesel surrogate. A sensitivity study was then performed on various model parameters resulting in improved agreement with experimental pressure and heat release rate.
Liu, Dai. "Combustion and emissions of an automotive diesel engine using biodiesel fuels under steady and start conditions." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5797/.
Повний текст джерелаBaranski, 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.
Повний текст джерелаEverett, Ryan Vincent. "An Improved Model-Based Methodology for Calibration of an Alternative Fueled Engine." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1321285633.
Повний текст джерелаFussey, Peter Michael. "Automotive combustion modelling and control." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:ec66cbb1-407e-431c-bd77-e67bcf33be3a.
Повний текст джерелаAl, Qubeissi Mansour. "Heating and evaporation of automotive fuel droplets." Thesis, University of Brighton, 2015. https://research.brighton.ac.uk/en/studentTheses/540596d9-e14f-4007-9533-acd625e14b8e.
Повний текст джерелаCuseo, James M. (James Michael). "Cold start fuel management of port-fuel-injected internal combustion engines." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32380.
Повний текст джерелаIncludes bibliographical references (p. 64).
The purpose of this study is to investigate how changes in fueling strategy in the second cycle of engine operation influence the delivered charge fuel mass and engine out hydrocarbon (EOHC) emissions in that and subsequent cycles. Close attention will be paid to cycle-to-cycle interaction of the fueling strategy. It is our intent to see if residual fuel from each cycle has a predicable influence on subsequent cycle's charge mass and EOHC emissions. The fast flame ionization detector is employed to measure both in-cylinder and engine out hydrocarbon concentrations for various cold start strategies. The manufacturer's original fueling strategy is used as a starting point and is compared to a "in-cylinder fuel air ratio (Phi) [approx.] 1" case (a fueling strategy that results in an in-cylinder concentration of approximately stoichiometric for each of the first five cycles) and to a number of cases that are chosen to illustrate cycle-to-cycle mixture preparation dependence on second cycle fueling. Significant cycle-to-cycle dependence is observed with the change in second cycle. A fueling deficit in cycle two has a more pronounce effect on future cycles delivered charge mass than a fueling surplus while a fueling surplus in cycle two has a more pronounce effect on future cycles charge mass than a fueling deficit.
by James M. Cuseo.
S.M.
Girgis, Elisabeth. "Fuel devolatilization in packed bed wood combustion." Thesis, University of Ottawa (Canada), 2004. http://hdl.handle.net/10393/26645.
Повний текст джерелаGoldsmith, Claude Franklin III. "Predicting combustion properties of hydrocarbon fuel mixtures." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59876.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 189-201).
In this thesis, I applied computational quantum chemistry to improve the accuracy of kinetic mechanisms that are used to model combustion chemistry. I performed transition state theory calculations for several reactions that are critical in combustion, including a detailed analysis of the pressure dependence of these rate coefficients. I developed a new method for rapidly estimating the vibrational modes and hindered rotor parameters for molecules. This new method has been implemented in an automatic reaction mechanism generation software, RMG, and has improved the accuracy of the density of states computed in RMG, which in turn has improved RMG's ability to predict the pressure-dependence of rate coefficients for complex reaction networks. I used statistical mechanics to compute the thermochemistry for over 170 of the most important species in combustion. These calculations form a new library of thermodynamic parameters, and this library will improve the accuracy of kinetic models, particularly for fuel lean conditions. I measured reaction rate coefficients using both laser flash-photolysis absorption spectroscopy in a slow-flow reactor and time-of-flight mass spectrometry and laser Schlieren densitometry in a shock tube. Based upon these experimental projects, I helped design a one-of-a-kind instrument for measuring rate coefficients for combustion-relevant reactions. The new reactor combines photoionization time-of-flight mass spectrometry with multi-pass absorption spectroscopy in a laser-flash photolysis cell. The cumulative effect of these efforts should advance our understanding of combustion chemistry and allow us to make more accurate predictions of how hydrocarbons burn.
by Claude Franklin Goldsmith, III.
Ph.D.
Crua, Cyril. "Combustion processes in a diesel engine." Thesis, University of Brighton, 2002. https://research.brighton.ac.uk/en/studentTheses/d0d73428-8bf3-460f-8297-f40572fd4bd7.
Повний текст джерелаZhang, Fan. "Spray, combustion and emission characteristics of dieseline fuel." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4699/.
Повний текст джерелаKronholm, David Franklin 1967. "Molecular weight growth pathways in fuel-rich combustion." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/8996.
Повний текст джерелаIncludes bibliographical references.
Polycyclic aromatic hydrocarbons (P AH) and soot are formed when a hydrocarbon fuel is oxidized under fuel-rich conditions. The distinction between what constitutes the largest P AH molecule and the smallest soot particle is arbitrary; the formation processes of both can be placed under the heading of molecular weight growth. Evidence exists for the carcinogenicity of many P AH molecules. Soot is used as a component of dyes and as an additive to rubbers as well as being an undesirable atmospheric pollutant. Both are emitted from many typical combustion processes such as diesel engines, wood fires, furnaces, etc. Though the area has received much attention, the fundamental chemical mechanisms for formation of both P AH and soot are still uncertain. Much debate has centered on the identity of the soot surface growth reactant, in particular whether the dominant surface growth reactant is P AH or acetylene. Though several models of soot formation exist, none has demonstrated through comparison to experimental data a thorough knowledge of the fundamental chemical processes of soot formation. The goal of this research was to further the understanding of these fundamental chemical processes. Since the chemistry of P AH and soot are intertwined, PAH was a necessary subcomponent of the soot formation research. The research was accomplished by obtaining soot particle size distribution data for the jet-stirred reactor/ plug-flow reactor (JSR/PFR), development of kinetics modeling methods, and the development of a kinetics model of soot formation. The JSR/PFR has been used extensively in the past to investigate P AH and soot formation, providing much data for concentrations of light-gas species, P AH, and soot under various conditions of equivalence ratio, temperature, and PFR additives. No experimental data have been obtained for soot particle size distribution in the JSR/PFR, so a study was undertaken here to obtain the soot particle size distributions for two conditions previously studied by Marr, premixed atmospheric ethylene combustion at equivalence ratio 2.2 and temperatures of 1520 K and 1620 K. Thermophoretic sampling was used to obtain soot samples for transmission electron micrograph analysis. Software was written and used to obtain soot particle sizes from electron micrographs. The chemical environment in a fuel-rich flame consists of many hundreds of species and thousands of chemical reactions. To isolate particular portions of the chemistry, a calculational technique was developed, data incorporation, that replaces chosen portions of the chemistry in kinetics models with functions of data concentrations. This technique was then used to isolate the process of P AH molecular weight growth and soot nucleation through the use of a discrete sectional model, and rate coefficients for hydrogen-atom abstraction, acetylene-addition, and PAH radical addition to PAH were obtained by comparisons to data from Marr for the 1620 K condition described above and the same condition with naphthalene injection into the PFR. The data incorporation technique was then used to expand the discrete sectional model to include sections describing soot, and the experimental soot size distribution data described above was used with previously available PFR data to obtain values for rate coefficients of PAHaddition to soot and coagulation of soot particles. Five PFR conditions were used to develop the soot formation model in these calculations, and the dominant mechanisms of soot formation present under these conditions appear to be present in the model. Quantitative agreement is obtained to all of the available data, including simultaneous agreement of soot mass and particle size, without significant deviation in the rate coefficients required to obtain agreement. Calculations were performed using both PAH and acetylene as the dominant soot surface growth reactant. It was found that P AH had far more consistent rate coefficient values (constant to within a factor of 4) than acetylene ( constant to within a factor of 59) to describe the data for all of the conditions. An analysis of the above five sets of conditions in the PFR, an additional three for the PFR, and three for premixed one-dimensional flames of acetylene, ethylene, and benzene, for which concentrations of acetylene, P AH. and soot, and in the case of the one-dimensional flames, soot particle size data, were available, were analyzed with the aim of understanding the dominant characteristics of the soot surface growth reactant. Soot mass growth rates were calculated for all of the conditions, and deviate markedly between the PFR and one-dimensional flames. Soot growth rate increases and oscillates in the PFR and sharply declines in the one-dimensional flames in the region of soot growth after initial particle inception. Under all of these conditions, PAH show the characteristics required of the dominant surface growth reactant: increases and oscillations in the PFR and sharp declines in the one-dimensional flames. For acetylene to be the dominant surface growth reactant, anomalous behavior of acetylene-suot reactivity would be required that cannot be explained by soot aging or radical intermediates. This leads to the observation that the long-held notion of declining soot reactivity in premixed one-dimensional flames similar to the ones studied here is a result of variations in the PAH intermediates and not a real phenomenon in the region after soot particle inception. An approximate method of uncertainty analysis of kinetics models was used to place an uncertainty bound of a factor of 3 on the rate coefficient parameters calculated. The approximate method was compared to more precise techniques and used to show that the uncertainty of concentration predictions with PAH kinetics models is of very large magnitude. The approximate uncertainty analysis technique was also used to show that the data incorporation technique reduces the uncertainty in calculated rate parameters by over two orders of magnitude. A kinetics model reduction algorithm was developed and implemented to reduce a PAH kinetics model fro.n 722 reactions and 187 species to 93 reactions and 52 species, maintaining naphthalene conc1;;ntration to within 9% of the original model. This technique was also used by Dinaro to redm:e a benzene oxidation model from 545 to 41 reactions for use in super-critical water oxidation applications.
by David Franklin Kronholm.
Ph.D.
Van, der Ham Gert A. "Liquid petroleum gas as automotive fuel in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52324.
Повний текст джерелаENGLISH ABSTRACT: The trends in worldwide fuel consumption and availability were studied, these indicated a bigger growth in gaseous fuel use than that of crude oil over the last decade. The economics (cost of converting and running vehicles on LPG) were studied and compared with those of petrol and diesel fuels. The government's approach to LPG taxation and the structure of the fuel price was also considered in an attempt to foresee what the future holds for LPG use in the motor industry. Gas fuelling systems that are currently available were studied and briefly described. The information obtained from the background study was used to help in the conversion of a two litre petrol engine. The engine was equipped to run on petrol Injection, liquid phase LPG injection and LPG carburettion. In-cylinder pressures, exhaust emissions and fuel consumption were amongst the parameters that were recorded for each fuel. The in-cylinder pressure measurements were used to study the combustion characteristics of petrol and LPG. Computer modeling was also used to investigate the trends that were recorded and this gave valuable insight into the different combustion characteristics of each fuel and the effect of gaseous versus liquid supply. For the passenger bus market a 12 litre 6 cylinder diesel engine was converted to LPG operation only. This required several changes to the pistons, cylinder head, inlet manifold and the addition of an electronic ignition system. Some changes had to be made to the squish characteristics of the pistons to make it suitable for homogeneous fuel air mixtures. The reasons for this were studied and described. Dynamometer tests revealed inadequacies in the ignition system that still need to be addressed before the engine can be built into a bus. Recommendations are made as to best utilize LPG in the South African Automotive industry, so as to improve public transport and air quality in some of our cities.
AFRIKAANSE OPSOMMING: 'n Studie van tendense in wêreldwye energieverbruik en besikbaarheid is gedoen. Dit het aan die lig gebring dat die groei in die gebruik van gasagtige brandstowwe in die laaste dekade die van ru-olie oortref het. Die lewensvatbaarheid van Vloeibare Petroleum Gas (VPG) voertuie, ombouing sowel as lopende koste, is bestudeer en vergelyk met die van Petrol en Diesel voertuie. Die regering se benadering tot belasting op VPG en die struktuur van die brandstofprys is ook ondersoek om te bepaal of die gebruik van VPG in n groter skaal as tans lewenvatbaar is. Vir tegniese agergrond is gas aangedrewe voertuie wêreldwyd bestudeer om te sien watter brandstof-voorsiening stelsels en enjins gebruik word. Die verskillende stelsels word bondig beskryf. Hierdie inligting is onder meer gebruik in die ombouing van n twee liter petrolenjin na VPG. Die enjin is toegerus om op beide petrol en VPG te loop terwyl die VPG in gasfase met behulp van 'n vergasser of as vloestof deur brandstof inspuiting toegedien kon word. Ontbrandingskamerdruk, uitlaatgasse en brandstofverbruik is van die parameters wat tydens toetse gemeet is. Die ontbrandingskamerdukmetings is gebruik om die verbrandingskarakteristieke van elke brandstof te bepaal. Nagebootste verbrandingstempos is in n rekeraarprogram gebruik om verskillende verbrandings karakteristieke wat gemeet is te ondersoek en tendense te bevestig. Vir die swaarvoertuigmark is 'n 12 Liter diesel enjin ombebou na VPG gebruik. Die dieselpomp en inspuiters is vervang met elektroniese vonkontsteking en vonkproppe. Die verbrandingskamer moes verander word om spontane verbranding tydens samepersing te voorkom. Die redes hiervoor is ondersoek en beskryf. Dinamo toetse het tekortkominge uitgewys in die elektroniese vonkontstekingsstelsel wat nog nie ten volle aangespreek is nie. Aanbevelings is gemaak om die toenemende gebruik van VPG as motorvoertuigbrandstof in Suid Afrika aan te bevorder om sodoende beter gebruik te maak van die beskikbare energie uit ru olie en ander bronne. Aanbevelings is ook gemaak ten opsigte van die gebruik van VPG in openbare vervoer en verbetering van lug gehalte in sommige stede.
Adamson, Kerry-Ann. "European Union policy, technical change and innovation in the automotive industry : can fuel cells challenge the existing paradigm?" Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249416.
Повний текст джерелаTurner, Dale Michael. "The combustion and emissions performance of fuel blends in modern combustion systems." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/1165/.
Повний текст джерелаNapier, Parhys L. "The individual contribution of automotive components to vehicle fuel consumption." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/68851.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 47-51).
Fuel consumption has grown to become a major point of interest as oil reserves are depleted. The purpose of this study is to determine the key components that cause variation in the instantaneous fuel consumption of vehicles and their level of impact using an in-depth literature review of technical papers. The literature is rigorously screened using an algorithm that excluded unreliable studies by criteria defined herein. Papers that are identified using this strategy are stratified according to vehicle subsystem and component. Relationships are established between external factors and fuel consumption using linear regression models and ranked by level of importance. Results show that coolant, air conditioning, alternator, rolling resistance and lubricants have an impact on vehicle fuel consumption and its variation. More specifically, coolant flow rate, oil viscosity, ambient temperature and tire pressure are found to be significant factors to fuel economy for the automobile.
by Parhys L. Napier.
S.B.
Balogun, Sunday Julius. "Static Optimization of Fuel Cell Plug-In Hybrid Electric Vehicle." Thesis, Northern Illinois University, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10978070.
Повний текст джерелаThis thesis focuses on the static optimization of a fuel cell plug-in hybrid electric vehicle. The vehicle is been powered by three (3) sources of electrical energy. These sources of electrical energy are: fuel cell, supercapacitor, and lithium-ion battery.
The main target of this thesis is to make good the performance of a fuel cell plug-in hybrid electric vehicle. This will be achieved by applying static optimization method on the dynamic equations of a moving hybrid vehicle.
The optimization model of this plug-in hybrid electric vehicle (PHEV) was formulated bases on multiple objectives. The objective parameters are: cost, volume, and mass. We were able to apply static optimization algorithm to find optimal solutions for both the objective values and decision variables of the multiple energy sources.
The optimization model formulated from the dynamic equations, objective specifications, and design constrains were found to be feasible, bounded, and optimizable by subjecting the primal optimization model to its equivalent dual optimization test.
Advanced vehicle simulator (ADVISOR) was used to stimulate vehicle performance of our design on a standard driving cycle. The results provide a better outcome than that of standard driving cycles.
Falk, Joel. "Effect of fuel composition and combustion conditions on phosphorus behavior during combustion of biomass." Licentiate thesis, Luleå tekniska universitet, Energivetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71240.
Повний текст джерелаKristyadi, Tarsisius. "Modelling of the heating and evaporation of fuel droplets." Thesis, University of Brighton, 2007. https://research.brighton.ac.uk/en/studentTheses/76ad22c1-5e09-410c-bec6-acf5bf1fe815.
Повний текст джерелаElwardani, Ahmed Elsaid Youssef Mohamed. "Modelling of multi-component fuel droplet heating and evaporation." Thesis, University of Brighton, 2012. https://research.brighton.ac.uk/en/studentTheses/ace0fc77-1fa9-4c7e-a33e-e18ecb0b9f84.
Повний текст джерелаFishbein, 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.
Повний текст джерелаLa 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.
Shroll, Andrew Philip. "Dynamic stability, blowoff, and flame characteristics of oxy-fuel combustion." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/67803.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 83-86).
Oxy-fuel combustion is a promising technology to implement carbon capture and sequestration for energy conversion to electricity in power plants that burn fossil fuels. In oxy-fuel combustion, air separation is used to burn fuel in oxygen to easily obtain a pure stream of carbon dioxide from the products of combustion. A diluent, typically carbon dioxide, is recycled from the exhaust to mitigate temperature. This substitution of carbon dioxide with the nitrogen in air alters the thermodynamics, transport properties, and relative importance of chemical pathways of the reacting mixture, impacting the flame temperature and stability of the combustion process. In this thesis, methane oxy-combustion flames are studied for relevance to natural gas. First, a numerical 1-D strained flame shows significantly reduced consumption speeds for oxy-combustion compared to air combustion at the same adiabatic flame temperature. Competition for the H radical from the presence of carbon dioxide causes high CO emissions. Elevated strain rates also cause incomplete combustion in oxy-combustion, demonstrated by the effect of Lewis number with a value greater than one for flame temperatures under 1900 K. Most of this work focuses on experimental results from premixed flames in a 50 kW axi-symmetric swirl-stabilized combustor. Combustion instabilities, upon which much effort is expended to avoid in gas turbines with low pollutant emissions, are described as a baseline for the given combustor geometry using overall sound pressure level maps and chemiluminescence images of 1/4, 3/4, and 5/4 wave mode limit cycles. These oxy-combustion results are compared to conventional air combustion, and the collapse of mode transitions with temperature for a given Reynolds number is found. Hysteresis effects in mode transition are important and similar for air and oxy-combustion. Blowoff trends are also analyzed. While oxy-combustion flames blow off at a higher temperature for a given Reynolds number due to weaker flames, there is an unexpected negative slope in blowoff velocity vs temperature for both air and oxy-combustion. The blowoff data are shown to collapse due to blowoff velocity being inversely proportional to the molar heat capacities of the burned gas mixtures at a given power. Finally, particle image velocimetry results are discussed to relate flow structures to corresponding flame structures.
by Andrew Philip Shroll.
S.M.
Kumar, Sri Adarsh A. "Cloud Computing based Velocity Profile Generation for Minimum Fuel Consumption." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1331083555.
Повний текст джерелаTingelöf, Thomas. "Polymer Electrolyte Fuel Cells in Reformate Power Generators." Doctoral thesis, KTH, Skolan för kemivetenskap (CHE), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-26938.
Повний текст джерелаQC 20101130
Rukas, Christopher J. "Prognostic Health Assessment of an Automotive Proton Exchange Membrane Fuel Cell System." Thesis, Rochester Institute of Technology, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1586450.
Повний текст джерелаProton exchange membrane fuel cells are a promising technology for the automotive industry. However, it is necessary to develop effective diagnostic tools to improve system reliability and operational life to be competitive in the automotive market. Early detection and diagnosis of fuel cell faults may lead to increased system reliability and performance. An efficient on-line diagnosis system may prevent irreparable damage due to poor control and system fatigue. Current attempts to monitor fuel cell stack health are limited to specialized tests that require numerous parameters. An increased effort exists to minimize parameter input and maximize diagnostic robustness. Most methods use complex models or black-box methods to determine a singular fault mode. Limited research exists with pre-processing or statistical methods. This research examines the effectiveness of a Naïve Bayes classifier on determining multiple states of health; such as healthy, dry, degraded catalyst, and inert gas build-up. Independent component analysis and principal component analysis are investigated for preprocessing. An automotive style fuel cell model is developed to generate data for these purposes. Since automotive applications have limited computational power, a system that minimizes the number of inputs and computational complexity is preferred.
Piaszyk, Jakub. "Animal fat (tallow) as fuel for stationary internal combustion engines." Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/4135/.
Повний текст джерелаHossain, Abu Noman. "Combustion of solid fuel in a fluidized bed combustor." Ohio University / OhioLINK, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1176492911.
Повний текст джерелаWu, Chunyang. "Fuel-NOx Formation during Low-Grade Fuel Combustion in a Swirling-Flow Burner." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1165.pdf.
Повний текст джерелаKorres, Michael. "Cylinder Pressure Sensor based Engine Combustion and Fuel System Diagnostics." Thesis, KTH, Fordonsdynamik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-203351.
Повний текст джерелаLlaniguez, Jeremy T. (Jeremy Tolentino) 1979. "A fundamental study of relationships among fuel properties, combustion characteristics and emission with normal and synthetic diesel fuel." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89930.
Повний текст джерелаBurger, Victor. "The design of a combustion test facility for synthetic jet fuel research." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/9495.
Повний текст джерелаWith the relatively recent emergence of non-petroleum-derived aviation gas turbine fuels, it was appropriate to review the complete list of jet-fuel specifications to assess whether they were sufficiently robust to ensure fit-forpurpose within the new paradigm. Although this has been an industry-wide endeavour, there were some particular research areas that were identified for special in-house attention by Sasol, as the world’s first commercial producer of approved and certified semi-synthetic and fully synthetic jet fuel. The project described in this report formed part of one of these research areas, which pertained to ignition and combustion stability in gas turbines and the role played by various fuel attributes and properties. The project was conducted at the Sasol Advance Fuels Laboratory based at the University of Cape Town. The project entailed the design and construction of a combustion test facility for conducting synthetic jet fuel research. The primary intended focus of the facility was the investigation of ignition and combustion stability behaviour of various test fuels, ranging from commercial jet fuel to single component model fuels. The scope of the project also included the design of both a basic homogeneous and a heterogeneous combustor which served to verify the facility’s suitability for investigating the influence of fuel chemistry and combustor inlet conditions on ignition and combustion stability limits.
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.
Повний текст джерелаSiemelink, Johannes Jacobus. "The effect of sulphur in fuel on the performance of automotive catalysts." Master's thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/21486.
Повний текст джерелаLopez, David M. "Controlling fuel and diluent gas flow for a diesel engine operating in the fuel rich low-temperature-combustion mode." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40455.
Повний текст джерелаIncludes bibliographical references (p. 37).
The flow of a diluent gas supplied to a motoring engine was controlled at a diluent to air mass flow ratios of 10%, 30%, 50%, and 70%. This arrangement was a significant set up for running the engine in the Low-Temperature Combustion mode. The engine used was a 436 cc Yanmar Diesel engine, driven at constant 2200 rpm by a 10 hp AC powered dynamometer. Intake air flow was measured by a model FMA-903-V Air Velocity Transducer by Omega Engineering, Inc., and the diluent gas flow was both measured and controlled by a model FMA-2613A Mass Flow Controller, also by Omega Engineering, Inc. Both were connected to a computer through a National Instruments USB-6211 data acquisition hub, and the signals from both were processed in real time through National Instruments' LabView 8.2 software. The diluent gas used was nitrogen. The flow controller was found to have reasonable flow precision but poor flow accuracy at many of the flow rates encountered during this experiment, with a minimum steady state error of 3.7% for a flow rate of 207.4 Standard Liters Per Minute (SLPM), the highest flow studied, and a maximum error of 97.4% at 53.8 SLPM, the lowest flow studied.
(cont.) The substantial error at low flow rates stems from the rated lower flow limit of the controller of 250 SLPM. A relation describing the amount of steady state error present was determined empirically, and either this equation or the implementation of an external PI controller can be used in the controlling LabView environment to decrease the steady state error.
by David M. Lopez.
S.B.
Michlberger, Alexander. "Development of Test Methodology for Evaluation of Fuel Economy in Motorcycle Engines." Cleveland State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=csu1397567798.
Повний текст джерелаGarcia, Pardo Diego. "Piston bowl combustion simulation - From fuel spray calibration to emissions minimization." Thesis, KTH, Mekanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-203950.
Повний текст джерелаBoettner, Daisie D. "Modeling of PEM fuel cell systems including controls and reforming effects for hybrid automotive applications." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1374767452.
Повний текст джерелаGong, Xiaohui Cernansky N. P. Miller David L. "The effects of DTBP on the oxidation of SI primary reference fuels - a study in an HCCI engine and in a pressurized flow reactor /." Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/550.
Повний текст джерелаBegg, Steven M. "In-cylinder airflow and fuel spray characteristics for a top-entry direct injection gasoline engine." Thesis, University of Brighton, 2003. https://research.brighton.ac.uk/en/studentTheses/ecdf9e55-604a-45af-a709-9839c57d282c.
Повний текст джерелаEstefanos, Wessam. "Effects of the Fuel-Air Mixing on Combustion Instabilities and NOx Emissions in Lean Premixed Combustion." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1460731723.
Повний текст джерелаHong, Jongsup. "Techno-economic analysis of pressurized oxy-fuel combustion power cycle for CO₂ capture." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/50567.
Повний текст джерелаIncludes bibliographical references (leaves 124-127).
Growing concerns over greenhouse gas emissions have driven extensive research into new power generation cycles that enable carbon dioxide capture and sequestration. In this regard, oxy-fuel combustion is a promising new technology for capturing carbon dioxide in power generation systems utilizing hydrocarbon fuels. Combustion of a fuel in an environment of oxygen and recycled combustion gases yields flue gases consisting predominantly of carbon dioxide and water. To capture carbon dioxide, water is condensed, and carbon dioxide is purified and compressed beyond its supercritical state. However, conventional atmospheric oxy-fuel combustion systems require substantial parasitic energy in the compression step within the air separation unit, a flue gas recirculation system and carbon dioxide purification and compression units. Moreover, a large amount of flue gas latent enthalpy, which has high water concentration, is wasted. Both lower the overall cycle efficiency. Alternatively, pressurized oxy-fuel combustion power cycles have been investigated. In this thesis, the analysis of an oxy-fuel combustion power cycle that utilizes a pressurized coal combustor is reported. We show that this approach is beneficial in terms of larger flue gas thermal energy recovery and smaller parasitic power requirements. In addition, we find the pressure dependence of the system performance to determine the optimal combustor operating pressure for this cycle.
(cont.) We calculate the energy requirements of each unit and determine the pressure dependence of the water-condensing thermal energy recovery and its relation to the gross power output. Furthermore, a sensitivity analysis is conducted on important operating parameters including combustor temperature, Heat Recovery Steam Generator outlet temperature, oxygen purity and oxygen concentration in the flue gases. A cost analysis of the proposed system is also conducted so as to provide preliminary cost estimates.
by Jongsup Hong.
S.M.
Yong, Sze Zheng. "Multiphase models of slag layer built-up in solid fuel gasification and combustion." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/61928.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 124-127).
A steady-state model has been developed to describe the flow and heat transfer characteristics of slag. The model incorporates two submodels for particle capture and wall burning; takes into consideration the temperature and composition dependent properties of slag, the contribution of momentum of captured particles and the possibility of slag resolidification. The model predicts the local thickness of molten and solid slag layers as well as the average slag velocity. Moreover, it is capable of predicting heat losses and the inner as well as outer wall temperatures, taking into account the influence of molten and resolidified slag layers coating the combustor or reactor wall. An equally important issue is the interaction of the particles colliding with the slag layer. High inertia particles tend to rebound whereas slower particles are trapped in the slag layer. Since only trapped particles are relevant to the slag layer built-up, a particle capture criterion for colliding particles is introduced. Particles with combustibles may be captured by the slag layer while they continue to bum at a different rate. To take this into account, a wall burning submodel is proposed to predict a correction factor for both solid and porous char combustion models.
by Sze Zheng Yong.
S.M.
Sone, Kazuo. "Unsteady simulations of mixing and combustion in internal combustion engines." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/12171.
Повний текст джерелаEkpe, Ngozi Chinwe. "Novel co-precipitated oxygen carriers for chemical looping combustion of gaseous fuel." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/39557/.
Повний текст джерелаBaker, Kelly Scott. "Effect of fuel volatility on fuel vaporization, combustion quality, and hydrocarbon emissions during starting and warm-up in spark-ignition engines." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/46103.
Повний текст джерелаBongartz, Dominik. "Chemical kinetic modeling of oxy-fuel combustion of sour gas for enhanced oil recovery." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/92224.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (pages 135-147).
Oxy-fuel combustion of sour gas, a mixture of natural gas (primarily methane (CH 4 )), carbon dioxide (CO 2 ), and hydrogen sulfide (H 2 S), could enable the utilization of large natural gas resources, especially when combined with enhanced oil recovery (EOR). Chemical kinetic modeling can help to assess the potential of this approach. In this thesis, a detailed chemical reaction mechanism for oxy-fuel combustion of sour gas has been developed and applied for studying the combustion behavior of sour gas and the design of power cycles with EOR. The reaction mechanism was constructed by combining mechanisms for the oxidation of CH4 and H2S and optimizing the sulfur sub-mechanism. The optimized mechanism was validated against experimental data for oxy-fuel combustion of CH4, oxidation of H2S, and interaction between carbon and sulfur species. Improved overall performance was achieved through the optimization and all important trends were captured in the modeling results. Calculations with the optimized mechanism suggest that increasing H2 S content in the fuel tends to improve flame stability through a lower ignition delay time. Water diluted oxy-fuel combustion leads to higher burning velocities at elevated pressures than CO 2 dilution or air combustion, which also facilitates flame stabilization. In a mixed CH4 and H2S flame, H25 is oxidized completely as CH4 is converted to carbon monoxide (CO). During CO burnout, some highly corrosive sulfur trioxide (SO3 ) is formed. Quenching of SO 3 formation in the combustor can only be achieved at the expense of higher CO emissions. The modeling of a gas turbine cycle showed that oxy-fuel combustion leads to SO 3 concentrations that are one to two orders of magnitude lower than in air combustion and will thus suffer much less from the associated corrosion problems. Slightly fuel-rich operation is most promising for achieving the low CO and oxygen (02) concentrations required for EOR while further minimizing SO 3. Carbon dioxide dilution is better for achiving low 02 in the EOR stream while H20 gives the better combustion efficiency.
by Dominik Bongartz.
S.M.
Yozgatligil, Ahmet Choi Mun Young. "Burning and sooting behavior of ethanol droplet combustion under microgravity conditions /." Philadelphia, Pa. : Drexel University, 2005. http://dspace.library.drexel.edu/handle/1860/475.
Повний текст джерелаAsay, Rich. "A Five-Zone Model for Direct Injection Diesel Combustion." BYU ScholarsArchive, 2003. https://scholarsarchive.byu.edu/etd/100.
Повний текст джерелаMackrory, Andrew John. "A Mechanistic Investigation of Nitrogen Evolution in Pulverized Coal Oxy-Fuel Combustion." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2640.pdf.
Повний текст джерелаLi, Yu. "A Numerical Investigation of Natural Gas-Diesel Dual Fuel Engine Combustion and Emissions Using CFD Model." Thesis, West Virginia University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10845305.
Повний текст джерелаNatural gas (NG)-diesel dual fuel engines have been highlighted for their fuel flexibility and high thermal efficiency comparable to diesel engines. However, the addition of NG to compression ignition diesel engines was reported to elongate ignition delay and to increase the emissions of carbon monoxide (CO), unburned methane (CH4), and nitrogen dioxide (NO2). Past research on dual fuel engines has focused on the experimental research on the engine performance, combustion process, and exhaust emissions. The research on detailed mechanism dominating the impact of CH4 on formation of CO and NO2 in cylinder, and the mechanism for CH 4 to survive the combustion process and slip through the cylinder is limited. The examinations of these mechanisms require the simulation of dual fuel engine combustion using a CFD model coupled with chemical kinetic mechanism.
This research numerically investigates the combustion process and exhaust emissions from two NG-diesel dual fuel engines using a CFD model coupled with a reduced primary reference fuel (PRF) chemistry. The CFD model used is Converge-SAGE model with a maximum of 300000 grid points. The fuel chemistry used is a reduced PRF mechanism with 45 species and 142 reactions including a reduced NOx mechanism with 4 species and 12 reactions. The CFD model with reduced PRF chemistry has been validated against experimental data measured in a single-cylinder compression-ignition engine over a wide range of CH4 substitution ratio. A post-processing tool has been developed to calculate, analyze, and visualize the instantaneous rate of production (ROP) of key species in each cell with the known temperature, pressure, and species concentration exported by CFD code. The simulation results are further post-processed to numerically investigate the combustion process and the formation mechanism of CO, and NO2 in a dual fuel engine. The mechanism for CH4 to survive the main combustion process and post-combustion oxidation process is numerically examined.
The research on NO2 formation identified NO+HO2→NO 2+OH as the key reaction dominating the increased formation of NO 2 in dual fuel engines. The HO2 necessary for the formation of NO2 emitted by the engine is produced through the post-oxidation of CH4 that survived the main combustion process. The CO emitted from the NG-diesel dual fuel engine is formed through the oxidation of CH 4 during the late combustion process and post-combustion CH4 oxidation. The CH4 that survived the main combustion and post-combustion oxidation process is mainly distributed in region far from the spray plume of the pilot fuel and its combustion products.
This research also examined approaches capable of significantly reducing the emissions of CH4 from a dual fuel engine. The preliminary results concluded that CH4 emissions can be significantly reduced through optimizing injection timing, and the application of two-pulse fuel injection strategy. Adjusting injector fuel spray angle can also significantly reduce CH4 emissions which should be considered in developing dedicated dual fuel engine.