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Fuel Spray Modeling for Compression Ignition Engine Configurations

Author : Krishna Latha Ankem

Publisher :

Page : 144 pages

File Size : 49,50 MB

Release : 2005

Category :

ISBN :

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Book Description

The combination of superior fuel economy and durability has made compression ignition direct injection diesel engines popular worldwide. However, these engines can emit large amounts of ozone-forming pollutants and particulates and so are being subjected to increasingly stringent regulations that require continual improvements in the combustion process. Further, improved engine power density is necessary at high load conditions, before the CIDI engine can be considered a contender in the next generation automotive engine technology. Understanding the physics and chemistry involved in diesel combustion, with its transient effects and the inhomogeneity of spray combustion is quite challenging. Great insight into the physics of the problem can be obtained when an in-cylinder computational analysis is used in conjunction with either an experimental program or through published experimental data. The main area to be investigated to obtain good combustion begins by defining the fuel injection process and the mean diameter of the fuel particle, injection pressure, drag coefficient, rate shaping, etc., correctly. This work presents a methodology to perform the task set out in the previous paragraph and uses experimental data obtained from available literature to construct a numerical model. A modified version of a multidimensional computer code called KIVA3V was used for the computations, with improved sub-models for mean droplet diameter, injection pressure and drop distortion and drag. The results achieved show good agreement with the published experimental data. It has been of special importance to model the spray distribution accurately, as the combustion process and the resulting pollutant emission formation is intimately tied to the in-cylinder fuel distribution. The present scheme has achieved excellent results in these aspects and will make an important contribution to the numerical simulation of the combustion process and pollutant emission formation in compression ignition direct injection engines.



Modelling Diesel Combustion

Author : P. A. Lakshminarayanan

Publisher : Springer Science & Business Media

Page : 313 pages

File Size : 34,61 MB

Release : 2010-03-03

Category : Technology & Engineering

ISBN : 904813885X

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Book Description

Phenomenology of Diesel Combustion and Modeling Diesel is the most efficient combustion engine today and it plays an important role in transport of goods and passengers on land and on high seas. The emissions must be controlled as stipulated by the society without sacrificing the legendary fuel economy of the diesel engines. These important drivers caused innovations in diesel engineering like re-entrant combustion chambers in the piston, lower swirl support and high pressure injection, in turn reducing the ignition delay and hence the nitric oxides. The limits on emissions are being continually reduced. The- fore, the required accuracy of the models to predict the emissions and efficiency of the engines is high. The phenomenological combustion models based on physical and chemical description of the processes in the engine are practical to describe diesel engine combustion and to carry out parametric studies. This is because the injection process, which can be relatively well predicted, has the dominant effect on mixture formation and subsequent course of combustion. The need for improving these models by incorporating new developments in engine designs is explained in Chapter 2. With “model based control programs” used in the Electronic Control Units of the engines, phenomenological models are assuming more importance now because the detailed CFD based models are too slow to be handled by the Electronic Control Units. Experimental work is necessary to develop the basic understanding of the pr- esses.



Modeling Engine Spray and Combustion Processes

Author : Gunnar Stiesch

Publisher : Springer Science & Business Media

Page : 314 pages

File Size : 14,82 MB

Release : 2003-04-10

Category : Computers

ISBN : 9783540006824

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Book Description

The utilization of mathematical models to numerically describe the performance of internal combustion engines is of great significance in the development of new and improved engines. Today, such simulation models can already be viewed as standard tools, and their importance is likely to increase further as available com puter power is expected to increase and the predictive quality of the models is constantly enhanced. This book describes and discusses the most widely used mathematical models for in-cylinder spray and combustion processes, which are the most important subprocesses affecting engine fuel consumption and pollutant emissions. The relevant thermodynamic, fluid dynamic and chemical principles are summarized, and then the application of these principles to the in-cylinder processes is ex plained. Different modeling approaches for the each subprocesses are compared and discussed with respect to the governing model assumptions and simplifica tions. Conclusions are drawn as to which model approach is appropriate for a specific type of problem in the development process of an engine. Hence, this book may serve both as a graduate level textbook for combustion engineering stu dents and as a reference for professionals employed in the field of combustion en gine modeling. The research necessary for this book was carried out during my employment as a postdoctoral scientist at the Institute of Technical Combustion (ITV) at the Uni versity of Hannover, Germany and at the Engine Research Center (ERC) at the University of Wisconsin-Madison, USA.



Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Author : National Research Council

Publisher : National Academies Press

Page : 373 pages

File Size : 39,47 MB

Release : 2011-06-03

Category : Science

ISBN : 0309216389

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Book Description

Various combinations of commercially available technologies could greatly reduce fuel consumption in passenger cars, sport-utility vehicles, minivans, and other light-duty vehicles without compromising vehicle performance or safety. Assessment of Technologies for Improving Light Duty Vehicle Fuel Economy estimates the potential fuel savings and costs to consumers of available technology combinations for three types of engines: spark-ignition gasoline, compression-ignition diesel, and hybrid. According to its estimates, adopting the full combination of improved technologies in medium and large cars and pickup trucks with spark-ignition engines could reduce fuel consumption by 29 percent at an additional cost of $2,200 to the consumer. Replacing spark-ignition engines with diesel engines and components would yield fuel savings of about 37 percent at an added cost of approximately $5,900 per vehicle, and replacing spark-ignition engines with hybrid engines and components would reduce fuel consumption by 43 percent at an increase of $6,000 per vehicle. The book focuses on fuel consumption-the amount of fuel consumed in a given driving distance-because energy savings are directly related to the amount of fuel used. In contrast, fuel economy measures how far a vehicle will travel with a gallon of fuel. Because fuel consumption data indicate money saved on fuel purchases and reductions in carbon dioxide emissions, the book finds that vehicle stickers should provide consumers with fuel consumption data in addition to fuel economy information.



Mixture Formation in Internal Combustion Engines

Author : Carsten Baumgarten

Publisher : Springer Science & Business Media

Page : 312 pages

File Size : 40,14 MB

Release : 2006-09-28

Category : Technology & Engineering

ISBN : 3540308369

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Book Description

A systematic control of mixture formation with modern high-pressure injection systems enables us to achieve considerable improvements of the combustion pr- ess in terms of reduced fuel consumption and engine-out raw emissions. However, because of the growing number of free parameters due to more flexible injection systems, variable valve trains, the application of different combustion concepts within different regions of the engine map, etc., the prediction of spray and m- ture formation becomes increasingly complex. For this reason, the optimization of the in-cylinder processes using 3D computational fluid dynamics (CFD) becomes increasingly important. In these CFD codes, the detailed modeling of spray and mixture formation is a prerequisite for the correct calculation of the subsequent processes like ignition, combustion and formation of emissions. Although such simulation tools can be viewed as standard tools today, the predictive quality of the sub-models is c- stantly enhanced by a more accurate and detailed modeling of the relevant pr- esses, and by the inclusion of new important mechanisms and effects that come along with the development of new injection systems and have not been cons- ered so far. In this book the most widely used mathematical models for the simulation of spray and mixture formation in 3D CFD calculations are described and discussed. In order to give the reader an introduction into the complex processes, the book starts with a description of the fundamental mechanisms and categories of fuel - jection, spray break-up, and mixture formation in internal combustion engines.





Combustion of Liquid Fuel Sprays

Author : Alan Williams

Publisher : Butterworth-Heinemann

Page : 300 pages

File Size : 22,93 MB

Release : 2013-10-22

Category : Technology & Engineering

ISBN : 1483101584

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Book Description

Combustion of Liquid Fuel Sprays outlines the fundamentals of the combustion of sprays in a unified way which may be applied to any technological application. The book begins with a discussion of the general nature of spray combustion, the sources of liquid fuels used in spray combustion, biomass sources of liquid fuels, and the nature and properties of fuel oils. Subsequent chapters focus on the properties of sprays, the atomization of liquid fuels, and the theoretical modeling of the behavior of a spray flame in a combustion chamber. The nature and control of pollutants from spray combustion, the formation of deposits in oil-fired systems, and the combustion of sprays in furnaces and engines are elucidated as well. The text is intended for students undertaking courses or research in fuel, combustion, and energy studies.



Modeling the Fuel Spray and Combustion Process of the Ignition Quality Tester with KIVA-3V

Author :

Publisher :

Page : 21 pages

File Size : 50,65 MB

Release : 2010

Category : Diesel motor

ISBN :

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Book Description

Developing advanced compression ignition and low-temperature combustion engines depends increasingly on chemical kinetic ignition models, but rigorous experimental validation of the models has been limited. Shock tubes and rapid compression machines are often limited to premixed gas-phase studies, precluding the use of realistic, low volatility diesel or biodiesel surrogates. The Ignition Quality Tester (IQT) constant-volume spray combustion system measures ignition delay of low-volatility fuels and could validate ignition models experimentally, but a better understanding of the IQT's processes is needed. KIVA-3V was used to develop a 3D CFD model that accurately reproduces ignition behavior and resolves temperature and equivalence ratio regions inside the IQT. The model's fuel spray characteristics (e.g., velocity) are experimentally validated, and it provides insight, vital to expanding the fuel research capabilities of the IQT, into the complex interaction between fuel spray and combustion processes.



Gasoline Compression Ignition Technology

Author : Gautam Kalghatgi

Publisher : Springer Nature

Page : 339 pages

File Size : 34,2 MB

Release : 2022-01-17

Category : Technology & Engineering

ISBN : 9811687358

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Book Description

This book focuses on gasoline compression ignition (GCI) which offers the prospect of engines with high efficiency and low exhaust emissions at a lower cost. A GCI engine is a compression ignition (CI) engine which is run on gasoline-like fuels (even on low-octane gasoline), making it significantly easier to control particulates and NOx but with high efficiency. The state of the art development to make GCI combustion feasible on practical vehicles is highlighted, e.g., on overcoming problems on cold start, high-pressure rise rates at high loads, transients, and HC and CO emissions. This book will be a useful guide to those in academia and industry.



Characterization of the Effects of Ducted Fuel Injection in a Compression Ignition Engine

Author : Christopher William Nilsen

Publisher :

Page : 0 pages

File Size : 48,70 MB

Release : 2020

Category :

ISBN :

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Book Description

Ducted fuel injection (DFI) has been proposed as a strategy to enhance the fuel/charge-gas mixing within the combustion chamber of a direct-injection mixing-controlled compression-ignition engine. The concept involves injecting each fuel spray through a small tube within the combustion chamber to facilitate the creation of a leaner mixture in the autoignition zone, relative to a conventional free-spray configuration (i.e., a fuel spray that is not surrounded by a duct). This dissertation investigates the effects of ducted fuel injection on engine-out emissions and efficiency with two-orifice and four-orifice injector tips across a wide range of conditions. A numerical study contributes to the understanding of the fluid flow effects of DFI. The experiments in chapter two use a two-orifice fuel injector to test two duct configurations relative to conventional diesel combustion. The result is that DFI is confirmed to be effective at curtailing engine-out soot emissions. It also breaks the tradeoff between emissions of soot and nitrogen oxides (NO[subscript x]) by simultaneously attenuating soot and NO[subscript x] with increasing dilution. The third chapter expands on the second by comparing ducted fuel injection to conventional diesel combustion over a wide range of operating conditions and at higher loads (up to 8.7 bar gross indicated mean effective pressure) with a four-orifice fuel injector. This chapter is achieved through sweeps of intake-oxygen mole-fraction, injection duration, intake pressure, start of combustion timing, fuel-injection pressure, and intake temperature. Ducted fuel injection is shown to curtail engine-out soot emissions at all tested conditions. Under certain conditions, ducted fuel injection can attenuate engine-out soot by over a factor of 100. In addition to producing significantly lower engine-out soot emissions, ducted fuel injection enables the engine to be operated at low-NO[subscript x] conditions that are not feasible with conventional diesel combustion due to high soot emissions. The fourth chapter explores 1.1 bar IMEP[subscript g] (low load) conditions and 10 bar IMEP[subscript g] (higher-load) conditions with the same four-orifice fuel injector as in chapter three. DFI and CDC are directly compared at each operating point in the study. At the idle condition, the intake dilution was swept to elucidate the soot and NO[subscript x] performance of DFI in this new load range. This expands the range of conditions over which DFI has been shown to attenuate soot formation. It also shows that DFI enables low-NO[subscript x], low-load operation that is not achievable with CDC due to excessive soot formation at high dilution levels. The fifth chapter uses a numerical model to develop the understanding of the fluid flow effects of DFI. This enabled studies of entrainment and mixing that would have been much more challenging to do in an experiment. This showed that DFI enhances charge gas entrainment before the duct and blocks entrainment inside of the duct. Mixing is enhanced by the duct, which resulted in lower peak equivalence ratios at the end of the duct.