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Price Divergence in the Gasoline Store Industry: Theoretical and Empirical ConsiderationsAlcaraz, Rafael January 2000 (has links)
No description available.
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PLANNING AND SCHEDULING OF CONTINUOUS PROCESSES VIA INVENTORY PINCH DECOMPOSITION AND GLOBAL OPTIMIZATION ALGORITHMS / INVENTORY PINCH DECOMPOSITION AND GLOBAL OPTIMIZATION METHODSCastillo Castillo, Pedro Alejandro January 2020 (has links)
Ph. D. Thesis / In order to compute more realistic production plans and schedules, techniques using nonlinear programming (NLP) and mixed-integer nonlinear programming (MINLP) have gathered a lot of attention from the industry and academy. Efficient solution of these problems to a proven ε-global optimality remains a challenge due to their combinatorial, nonconvex, and large dimensionality attributes.
The key contributions of this work are: 1) the generalization of the inventory pinch decomposition method to scheduling problems, and 2) the development of a deterministic global optimization method.
An inventory pinch is a point at which the cumulative total demand touches its corresponding concave envelope. The inventory pinch points delineate time intervals where a single fixed set of operating conditions is most likely to be feasible and close to the optimum. The inventory pinch method decomposes the original problem in three different levels. The first one deals with the nonlinearities, while subsequent levels involve only linear terms by fixing part of the solution from previous levels. In this heuristic method, infeasibilities (detected via positive value of slack variables) are eliminated by adding at the first level new period boundaries at the point in time where infeasibilities are detected.
The global optimization algorithm presented in this work utilizes both piecewise McCormick (PMCR) and Normalized Multiparametric Disaggregation (NMDT), and employs a dynamic partitioning strategy to refine the estimates of the global optimum. Another key element is the parallelized bound tightening procedure.
Case studies include gasoline blend planning and scheduling, and refinery planning. Both inventory pinch method and the global optimization algorithm show promising results and their performance is either better or on par with other published techniques and commercial solvers, as exhibited in a number of test cases solved during the course of this work. / Thesis / Doctor of Philosophy (PhD) / Optimal planning and scheduling of production systems are two very important tasks in industrial practice. Their objective is to ensure optimal utilization of raw materials and equipment to reduce production costs. In order to compute realistic production plans and schedules, it is often necessary to replace simplified linear models with nonlinear ones including discrete decisions (e.g., “yes/no”, “on/off”). To compute a global optimal solution for this type of problems in reasonable time is a challenge due to their intrinsic nonlinear and combinatorial nature.
The main goal of this thesis is the development of efficient algorithms to solve large-scale planning and scheduling problems. The key contributions of this work are the development of: i) a heuristic technique to compute near-optimal solutions rapidly, and ii) a deterministic global optimization algorithm. Both approaches showed results and performances better or equal to those obtained by commercial software and previously published methods.
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Statistical Adequacy and Reliability of Inference in Regression-like ModelsRomero, Alfredo A. 09 June 2010 (has links)
Using theoretical relations as a source of econometric specifications might lead a researcher to models that do not adequately capture the statistical regularities in the data and do not faithfully represent the phenomenon of interest. In addition, the researcher is unable to disentangle the statistical and substantive sources of error and thus incapable of using the statistical evidence to assess whether the theory, and not the statistical model, is wrong. The Probabilistic Reduction Approach puts forward a modeling strategy in which theory can confront data without compromising the credibility of either one of them. This approach explicitly derives testable assumptions that, along with the standardized residuals, help the researcher assess the precision and reliability of statistical models via misspecification testing. It is argued that only when the statistical source of error is ruled out can the researcher reconcile the theory and the data and establish the theoretical and/or external validity of econometric models.
Through the approach, we are able to derive the properties of Beta regression-like models, appropriate when the researcher deals with rates and proportions or any other random variable with finite support; and of Lognormal models, appropriate when the researcher deals with nonnegative data, and specially important of the estimation of demand elasticities. / Ph. D.
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The relative economic value of gasoline and kerosene as fuel for a heavy duty engineAlvis, J. K. January 1930 (has links)
A high compression type engine operates far more satisfactorily on gasoline than on kerosene.
Frequent oil changes are necessary when kerosene is used.
When burning gasoline the engine operated on fuel-air mixtures varying from 1 - 17.5 to 1 - 7.48 by weight. The most economical ratio was 1 - 15.2, with the intake air at 135° F. The most powerful mixture was a ratio of 1 - 12.3*, and intake air at 86.2° F.
Kerosene mixtures varied. from 1 - 7.41 to 1 - 16.75. Greatest economy was secured on a mixture of 1 - 15.62, air intake at 134° F. The most power was developed from kerosene on a mixture of 1 - 13.3*, and an air temperature of 80° F.
The efficiency of the engine on the most powerful mixtures was 19.75% for gasoline at 23.05 H.P.,and 25.7% for kerosene at 22.85 H.P.
The engine developed as much power from a pound of kerosene as from a pound of gasoline.
Gasoline and kerosene require practically the same external conditions for optimum operation.
Kerosene does not deposit a great deal more carbon than gasoline.
Heat added to the intake air gives greater engine economy, but at the same time decreases its capacity.
135° F. gave the most economy in both fuels.
Hot air and lean mixtures makes the engine knock on gasoline.
The engine knocked with kerosene at all heats on practically all mixtures. Speed above 1350 R.P.M.,and low water temperatures *Average of three mixtures used on power curve. minimize the “pinging”
The outlet water must be kept above 180° F when burning kerosene.
Oil “stands up” better while burning gasoline.
Nine gallons of kerosene produce power equivalent to that produced by ten gallons of gasoline. / M.S.
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[en] DISSOLUTION OF GASOLINE IN PRESENCE OF WATER AND ETHANOL / [pt] DISSOLUÇÃO DE GASOLINA EM PRESENÇA DE ÁGUA E ETANOLKLITIA VALESKA BICALHO 26 November 2001 (has links)
[pt] Muitos contaminantes orgânicos, incluindo derivados do
petróleo, como por exemplo a gasolina, têm baixa
solubilidade em água e migram na subsuperfície como uma
fase separada da água sendo referidos como NAPLs (non
aqueous liquid phases). Em seu processo de migração na
subsuperficie os NAPLs deixam para trás segmentos de
líquidos disconectados na forma de gânglios ou lentes que
constituem a fase residual do contaminante. A presença
do contaminante residual constitui-se numa das maiores
dificuldades para a implementação de uma técnica adequada
de limpeza ou recuperação de locais contaminados, uma vez
que tais contaminantes representam uma fonte lenta e
continua de contaminação de solos e água subterrânea,
especialmente por sua dissolução na água.
Nesta tese, estudou-se o efeito do etanol na dissolução de
gasolina residual. Tal estudo foi motivado pela necessidade
de se obter um melhor entendimento de um cenário de
contaminação envolvendo gasolina e etanol uma vez que
gasolina com 20 por cento de etanol em sua constituição e etanol
puro estão sendo utilizados como combustível, no Brasil,
nos últimos 20 anos. O uso de aditivos oxigenados à
gasolina, tais como álcoois, objetiva aumentar o
desempenho do motor dos automóveis bem como diminuir a
emissão de CO2 destes para a atmosfera e este uso vem
aumentando em muitos países. Experimentos tipo equilíbrio
em lote e experimentos de coluna foram realizados para
investigar efeitos do etanol na solubilidade de
constituintes da gasolina e no coeficiente de transferência
de massa da gasolina para fase aquosa. Colunas de solo
arenoso com gasolina em saturação residual foram percoladas
por soluções aquosas com diferentes teores de etanol.
Os resultados das concentrações efluentes de contaminante
ao longo do tempo, obtidas destes ensaios, foram
interpretados segundo o modelo de dissolução proposto por
Frind et al. (1997), modificado nesta tese para considerar
os efeitos de cosolvência do etanol na solubilidade dos
constituintes da gasolina. Os resultados experimentais
obtidos indicam que um cenário de contaminação envolvendo
etanol e gasolina deverá ser bastante diferente daquele de
contaminação usual de gasolina.Em um cenário de
contaminação envolvendo etanol e gasolina, concentrações
mais altas de contaminantes na água serão esperadas bem
como diferentes constituintes da gasolina, além do
tradicional grupo BTEX (benzeno, tolueno, etilbenzeno e os
isômeros xilenos) deverão estar presentes na água em
concentrações nocivas ao meio ambiente. / [en] Many organic contaminants, including petroleum products,
such as gasoline, have low aqueous solubilities and migrate
through the subsurface as a separated phase called NAPLs
(non aqueous liquid phases). In its flow path into the
porous media the NAPLs let behind disconnected segments of
organic liquids entrapped as ganglia or lenses that form
the residual phase of the contaminant. The presence of the
residual contaminant has been reported as one of the most
difficulties in the development of an appropriate cleanup
strategy as the residual phase represents a long and
continuum source of contamination of soils and groundwater,
specially by its dissolution into the water.In this thesis
the effect of ethanol on dissolution of residual gasoline
was studied, aiming at a better understanding of a scenario
of groundwater contamination involving gasoline and
ethanol, since 20 percent of ethanol has been added to the
Brazilian gasoline in the last 20 years and also ethanol
has been used as fuel in Brazil in these years. The use of
oxygenated additives into the gasoline, such as alcohols,
has the advantage of improving engine performance and
reducing the air impact pollution by CO2 and its use has
increasing in many countries.Equilibrium batch tests and
column experiments were carried out to investigate the
effect of ethanol on solubility of gasoline constituents
and on the mass transfer coefficient from gasoline to
aqueous phase. The results of the column experiments were
interpreted with a dissolution numerical model proposed by
Frind et al.(1997), modified in this thesis to include
the cosolvent effects of the ethanol on the solubility of
gasoline constituents.In terms of soil and groundwater
contamination related to gasoline spills, chemicals like
benzene, toluene, ethylbenzene and xylenes (BTEX group)
have acute toxicity or carcinogenicity, are the most water-
soluble and mobile gasoline components, receiving the
greatest concern. In this work, an enormous enhancement of
gasoline constituents solubility due to ethanol was
observed, and it was also noticed that the mass transfer
coefficient diminished due to ethanol. The highest increase
in solubility were for the less water soluble components.
Therefore, gasoline components, other than BTEX, are
expected in significant concentrations, in a scenario of
contamination involving ethanol and therefore more concern
about this potential threat should be addressed.
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Potential of ozone to enable the low load operation of a Gasoline Compression Ignition engine / Potentiel de l’ozone pour atteindre le fonctionnement en faible charge d’un moteur essence à allumage par compressionPinazzi, Pietro Matteo 18 January 2018 (has links)
Le moteur essence à allumage par compression (GCI), reposant sur la combustion partiellement prémélangée de l'essence (GPPC), peut potentiellement assurer des opérations efficaces et propres. Le moteur GCI s'est avéré efficace à forte charge, mais l'indice d'octane élevé de l'essence limite considérablement les opérations à faible charge. Le présent travail étudie le potentiel de l'utilisation de l'ozone, fort agent oxydant, pour améliorer la réactivité de l'essence et permettre le fonctionnement à faible charge de GCI. L'ozone peut être produit on board en équipant le moteur d'un générateur d'ozone, sans impact dramatique sur le coût du moteur et sur la complexité du contrôle du moteur. Les essais effectués avec un moteur monocylindre ont montré que l'ozone favorise la combustion HCCI de l'essence, permettant d'étendre la limite d’auto-inflammation et de réduire la température minimale nécessaire de celle-ci. Les diagnostics optiques ont montré que ces propriétés sont liées à une prolifération radicale accrue, amenées par des réactions à basse température induites par l'ozone. En parallèle, le processus de combustion GCI a été étudié dans des conditions de faible charge. Sans ozone, la température d'admission doit être considérablement augmentée pour permettre l'auto-inflammationdes mélanges essence-air pauvres. De plus, les résultats indiquent que le monoxyde d’azote (NO) contenu dans les gaz brûlés résiduels peut, dans certaines conditions, favoriser fortement la combustion GCI. Ensuite,l'effet de l'ozone a été étudié dans des conditions d'injection directe GCI. Les résultats démontrent qu’une stratégie avec double injection est nécessaire pour maximiser l’effet promoteur de l’ozone et pour contrôler le processus de combustion GCI. Enfin, l'utilisation d’une forte concentration d’ozone a permis d’atteindre des opérations à faible charge en mode GCI, avec des faibles émissions de NOx et de suie, et cela, sans avoir besoin d'augmenter la température ou la pression d'admission. / Gasoline Compression Ignition (GCI) engine, relying on Gasoline Partially Premixed Combustion (GPPC) has potential for efficient and clean operations. GCI engine showed to be effective at high load, however, the highoctane number of gasoline dramatically limits low load operations. The present work investigates the potential of using ozone, a strong oxidizing agent, to improve gasoline reactivity and enabling low load GCI operation.Ozone can be produced in-situ and on-demand by equipping the engine with an ozone generator, without a dramatic impact on the engine cost and the engine control complexity. Experiments in a single cylinder engine showed that ozone promotes gasoline HCCI combustion, making possible to extend the lean limit and reducing the minimum temperature needed for autoignition. Optical diagnostics showed that these properties are related to an increased radical proliferation related to ozone-induced low temperature reactions. In parallel, GCI combustion process was investigated under low load conditions. Without ozone, the intake temperature should be considerable increased to enable auto ignition of lean gasoline-air mixtures. Moreover, results indicated that the NO contained into residual burnt gases can strongly promote GCI low load combustion. Finally, the effect of ozone was investigated under GCI direct-injection conditions, demonstrating that low load GCI operation with low NOx and Soot emission can be achieved by seeding the intake of the engine with ozone without needing of increasing the intake charge temperature or boosting the intake pressure.
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Determinantes da adulteraÃÃo dos combustÃveis / Determinants tampering fuelCarlos Brasil Gouveia 08 February 2012 (has links)
nÃo hà / This work contributes to a better understanding of the phenomenon of adulteration of fuel, in
order to identify possible economic determinants related to this practice. With the objective of
a complete description of the problem, there is the need to preliminarily study the oil industry,
which was done transpiring succinctly, from the birth of the oil industry to the current stage of
it, featuring and highlighting its most important aspects for the economy. Then it approaches
the question of asymmetric information present in the fuel retail markets, and finally through
the construction of econometric models that take into account assumptions formalized in
works related to the problem of adulteration of fuel, then the evidence to economic
determinants. / Este trabalho contribui para um melhor entendimento do fenÃmeno da adulteraÃÃo de
combustÃveis, visando à identificaÃÃo de possÃveis determinantes econÃmicos, relacionados a
tal prÃtica. Tendo por objetivo uma perfeita caracterizaÃÃo do problema, verifica-se,
preliminarmente, a necessidade de estudar o setor petrolÃfero, e assim foi feito transcorrendo
de maneira sucinta, do nascimento da indÃstria do petrÃleo ao atual estÃgio da mesma,
caracterizando e ressaltando seus aspectos mais importantes para a economia. Posteriormente,
aborda-se a questÃo da assimetria de informaÃÃes presente nos mercados varejistas de
combustÃveis, e, finalmente, atravÃs da construÃÃo de modelos economÃtricos que levem em
conta pressupostos formalizados nos trabalhos relacionados ao problema da adulteraÃÃo de
combustÃveis, evidenciando-se entÃo os determinantes econÃmicos.
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Toxicidade aguda sobre Daphnia similis decorrente de contaminação aquática recente e antiga por gasolina, etanol e suas misturas: simulações em escala de bancada. / Acute toxicity on Daphnia similis resulting from recent and aged aquatic contamination by gasoline, ethanol and their mixtures: simulations via lab scale.Ludmila da Silva Cunha 11 February 2014 (has links)
A contaminação de ambientes aquáticos decorrente de acidentes com
gasolina, álcool combustível e misturas binárias representa um risco crescente,
tendo em vista as projeções do setor para os próximos 50 anos. O objetivo do
presente estudo foi avaliar a toxicidade aguda da Gasolina C, Gasolina P e álcool
combustível isoladamente e em misturas binárias, assim como de suas respectivas
Frações Solúveis em Água (FSA) e Frações Dispersas em Água (FDA) sobre
Daphnia similis. O estudo ainda incluiu a avaliação da toxicidade aguda
remanescente na matriz água de uma contaminação antiga (intemperismo) com a
Gasolina C. Paralelamente, foram conduzidos ensaios de toxicidade aguda com
amostras ambientais (água subterrânea, superficial e elutriato a partir de
sedimentos) de uma área alagada com histórico de contaminação antiga. O cultivo e
os ensaios com D. similis foram de acordo com a NBR 12.713 (2009). Tanto a
gasolina C quanto a P foram extremamente tóxicas para os organismos,
apresentando valores médios de CE50% em 48 h de 0,00113% e 0,058%
respectivamente. As diferenças entre os resultados obtidos com a Gasolina C e
aqueles obtidos com suas frações FSA e FDA foram significativas (p < 0,05), sendo
que não houve diferença significativa entre a toxicidade aguda da FSA e da FDA (p
< 0,05). Os resultados obtidos com os ensaios com Gasolina P e FDA não
apresentaram diferenças significativas entre si (p < 0,05), mas, foram
significativamente diferentes daqueles obtidos com FSA (p < 0,05). Os resultados
dos ensaios de toxicidade aguda com misturas binárias sugeriram efeito menos que
aditivo (antagonismo). Os resultados da simulação de uma contaminação antiga
demonstraram redução acentuada da toxicidade para D. similis ao longo de apenas
28 dias. Entretanto, com relação aos ensaios com as amostras ambientais da área
com histórico de contaminação, apesar da ausência ou baixa toxicidade nas
amostras de água superficial (sugerindo intemperismo), toxicidade alta foi observada
em amostras de água subterrânea e no elutriato de sedimentos, sugerindo
condições de adsorção aos sedimentos com alto teor de argila e/ou aprisionamento
dos compostos em zona saturada. / The contamination of aquatic environments due to accidents with gasoline,
alcohol fuel and their mixtures represents an increasing risk due to the projections
made by the petroleum-based fuels industry for the next 50 years. The objective of
the present study was to assess the acute toxicity of gasoline C, gasoline P, ethanol
fuel separately and in mixtures, as well as their respective water-soluble fractions
(WSF) and water-disperse fraction (WDF) on the bioindicator Daphnia similis. The
study also included the assessment of the remaining acute toxicity in an aged
gasoline C-contaminated water matrix with aging simulation for a 28-day period.
Parallel to that, toxicity assays were conducted with environmental samples,
including surface water, elutriate of sediments and groundwater from an aged
contaminated area. The cultivation and the assays with D. similis were carried out
according to NBR 12.713 (2009). Both gasoline C and P were highly toxic to D.
similis, with CE50% in 48 h of 0.00113% e 0.058% respectively. The differences in
acute toxicity between Gasoline C and its fractions WSF and WDF were significant (p
<0.05). However, no significant difference was found between WSF and WDF
fractions. Gasoline P and its WDF fraction had no significant differences (p < 0.05),
but their toxicity were significant different from that one obtained with the FSA
fraction (p < 0.05). Acute toxicity assays carried out with gasoline C and P mixed with
ethanol fuel suggested effect less than additive (antagonism). The results obtained
with the simulation of an aged contamination with Gasoline C showed sharp
reduction in toxicity along 28 days. However, regarding the assays with
environmental samples from an aged contamination, although absence or low toxicity
was observed in the superficial water, severe toxicity was found in the sediments
elutriate and in the groundwater, which was confirmed by the high concentrations of
gasoline hydrocarbons in both matrixes. The results suggest that the contaminant
was entrapped in the saturated zone and/or adsorbed to the sediments with high clay
content.
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Toxicidade aguda sobre Daphnia similis decorrente de contaminação aquática recente e antiga por gasolina, etanol e suas misturas: simulações em escala de bancada. / Acute toxicity on Daphnia similis resulting from recent and aged aquatic contamination by gasoline, ethanol and their mixtures: simulations via lab scale.Ludmila da Silva Cunha 11 February 2014 (has links)
A contaminação de ambientes aquáticos decorrente de acidentes com
gasolina, álcool combustível e misturas binárias representa um risco crescente,
tendo em vista as projeções do setor para os próximos 50 anos. O objetivo do
presente estudo foi avaliar a toxicidade aguda da Gasolina C, Gasolina P e álcool
combustível isoladamente e em misturas binárias, assim como de suas respectivas
Frações Solúveis em Água (FSA) e Frações Dispersas em Água (FDA) sobre
Daphnia similis. O estudo ainda incluiu a avaliação da toxicidade aguda
remanescente na matriz água de uma contaminação antiga (intemperismo) com a
Gasolina C. Paralelamente, foram conduzidos ensaios de toxicidade aguda com
amostras ambientais (água subterrânea, superficial e elutriato a partir de
sedimentos) de uma área alagada com histórico de contaminação antiga. O cultivo e
os ensaios com D. similis foram de acordo com a NBR 12.713 (2009). Tanto a
gasolina C quanto a P foram extremamente tóxicas para os organismos,
apresentando valores médios de CE50% em 48 h de 0,00113% e 0,058%
respectivamente. As diferenças entre os resultados obtidos com a Gasolina C e
aqueles obtidos com suas frações FSA e FDA foram significativas (p < 0,05), sendo
que não houve diferença significativa entre a toxicidade aguda da FSA e da FDA (p
< 0,05). Os resultados obtidos com os ensaios com Gasolina P e FDA não
apresentaram diferenças significativas entre si (p < 0,05), mas, foram
significativamente diferentes daqueles obtidos com FSA (p < 0,05). Os resultados
dos ensaios de toxicidade aguda com misturas binárias sugeriram efeito menos que
aditivo (antagonismo). Os resultados da simulação de uma contaminação antiga
demonstraram redução acentuada da toxicidade para D. similis ao longo de apenas
28 dias. Entretanto, com relação aos ensaios com as amostras ambientais da área
com histórico de contaminação, apesar da ausência ou baixa toxicidade nas
amostras de água superficial (sugerindo intemperismo), toxicidade alta foi observada
em amostras de água subterrânea e no elutriato de sedimentos, sugerindo
condições de adsorção aos sedimentos com alto teor de argila e/ou aprisionamento
dos compostos em zona saturada. / The contamination of aquatic environments due to accidents with gasoline,
alcohol fuel and their mixtures represents an increasing risk due to the projections
made by the petroleum-based fuels industry for the next 50 years. The objective of
the present study was to assess the acute toxicity of gasoline C, gasoline P, ethanol
fuel separately and in mixtures, as well as their respective water-soluble fractions
(WSF) and water-disperse fraction (WDF) on the bioindicator Daphnia similis. The
study also included the assessment of the remaining acute toxicity in an aged
gasoline C-contaminated water matrix with aging simulation for a 28-day period.
Parallel to that, toxicity assays were conducted with environmental samples,
including surface water, elutriate of sediments and groundwater from an aged
contaminated area. The cultivation and the assays with D. similis were carried out
according to NBR 12.713 (2009). Both gasoline C and P were highly toxic to D.
similis, with CE50% in 48 h of 0.00113% e 0.058% respectively. The differences in
acute toxicity between Gasoline C and its fractions WSF and WDF were significant (p
<0.05). However, no significant difference was found between WSF and WDF
fractions. Gasoline P and its WDF fraction had no significant differences (p < 0.05),
but their toxicity were significant different from that one obtained with the FSA
fraction (p < 0.05). Acute toxicity assays carried out with gasoline C and P mixed with
ethanol fuel suggested effect less than additive (antagonism). The results obtained
with the simulation of an aged contamination with Gasoline C showed sharp
reduction in toxicity along 28 days. However, regarding the assays with
environmental samples from an aged contamination, although absence or low toxicity
was observed in the superficial water, severe toxicity was found in the sediments
elutriate and in the groundwater, which was confirmed by the high concentrations of
gasoline hydrocarbons in both matrixes. The results suggest that the contaminant
was entrapped in the saturated zone and/or adsorbed to the sediments with high clay
content.
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Optical analysis of multi-stream GDI sprays under various engine operating conditionsMojtabi, Mehdi January 2011 (has links)
The design and optimisation of a modern gasoline direct injection (GDI) engine requires a thorough understanding of the fuel sprays characteristics and atomisation process.Therefore this thesis presents a detailed optical analysis of atomisation, penetration and interaction of multi-stream GDI sprays under engine relevant pressures and temperatures. The characteristics of the fuel spray in a GDI engine have a great influence on the fuel-air mixing and combustion processes as fuel injectors must provide adequate atomisation for vaporisation of the fuel to take place before combustion is initiated, whilst also avoiding spray impingement on the cylinder walls or piston crown. In this study multi-stream injectors, to be used within GDI engines, are quantified using Laser Doppler Anemometry (LDA) on an atmospheric bench. This process allowed for highly detailed spray analysis of droplet velocities and diameter at precise locations, using a three dimensional traverse, within the injector spray. The aim of the study was to analyse plume interaction between separate plumes of multi-stream injectors. Three multi-stream injectors were subjected to testing; two six-hole injectors and one three-hole injector. The injectors differed by having different distances between the plumes. The effect of fuel type on the liquid break-up and atomisation was investigated using Phase Doppler Anemometry (PDA) and Mie imaging. Mie imaging was also performed to capture images of fuel from a multi-stream injector as it was sprayed into a pressure chamber which was used to recreate the conditions found in an engine likely to cause flash boiling. In total, five variables were investigated: fuel pressure, ambient pressure, ambient temperature, fuel composition and injector geometry. Once processed, the recorded images allowed measurement of spray tip penetration and cone angle. Qualitative data on the change in shape of the spray was also available. The results showed that flash boiling has potential to reduce droplet diameters and improve fuel vaporisation, however, the associated change in spray shape must be taken into account to avoid problems with spray impingement. Keywords: Gasoline Direct Injection, multi-stream injector, atomisation, penetration, cone angle, Mie imaging, Phase Doppler Anemometry, flash boiling.
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