Download or read book Numerical Study of Transient Fuel Sprays with Autoignition and Combustion Under Diesel Engine Relevant Conditions written by Yuepeng Wan and published by . This book was released on 1997 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Study of Transient In nozzle Fuel Flow Phenomena and Near nozzle Effects During and After the End of Injection for Diesel Engines written by Nikolaos Papadopoulos and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Droplets and Sprays written by Saptarshi Basu and published by Springer. This book was released on 2017-12-11 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on droplets and sprays relevant to combustion and propulsion applications. The book includes fundamental studies on the heating, evaporation and combustion of individual droplets and basic mechanisms of spray formation. The contents also extend to the latest analytical, numerical and experimental techniques for investigating the behavior of sprays in devices like combustion engines and gas turbines. In addition, the book explores several emerging areas like interactions between sprays and flames and the dynamic characteristics of spray combustion systems on the fundamental side, as well as the development of novel fuel injectors for specific devices on the application side. Given its breadth of coverage, the book will benefit researchers and professionals alike.

Download or read book Numerical Study of Transient In nozzle Fuel Flow Phenomena and Near nozzle Effects During and After the End of Injection for Diesel Engines written by N. Papadopoulos and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solving Ordinary Differential Equations II written by Ernst Hairer and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Whatever regrets may be, we have done our best." (Sir Ernest Shackleton, turning back on 9 January 1909 at 88°23' South.) Brahms struggled for 20 years to write his first symphony. Compared to this, the 10 years we have been working on these two volumes may even appear short. This second volume treats stiff differential equations and differential alge braic equations. It contains three chapters: Chapter IV on one-step (Runge Kutta) methods for stiff problems, Chapter Von multistep methods for stiff problems, and Chapter VI on singular perturbation and differential-algebraic equations. Each chapter is divided into sections. Usually the first sections of a chapter are of an introductory nature, explain numerical phenomena and exhibit numerical results. Investigations of a more theoretieal nature are presented in the later sections of each chapter. As in Volume I, the formulas, theorems, tables and figures are numbered consecutively in each section and indicate, in addition, the section num ber. In cross references to other chapters the (latin) chapter number is put first. References to the bibliography are again by "author" plus "year" in parentheses. The bibliography again contains only those papers which are discussed in the text and is in no way meant to be complete.

Download or read book Spray and Combustion Studies of High Reactivity Gasoline in Comparison to Diesel Under Advanced Compression Ignition Engine Conditions written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Gasoline compression ignition (GCI) technology has demonstrated great potentials in improving fuel economy and reducing engine-out NOx and particulate matter emissions. Development and application of the GCI technology on multi-cylinder engines require both fundamental understandings of the gasoline spray combustion characteristics and accurate numerical tools. Due to the large differences in the thermo-physical and the chemical properties between gasoline and diesel range fuels, differences in the spray combustion characteristics between gasoline and diesel is expected. Reports on the gasoline spray combustion characteristics under conditions relevant to medium to heavy-duty engines are scarce and this dissertation aims to fill in this knowledge gap. Experimental work were performed in a constant volume combustion vessel. Non-reacting sprays under low and high ambient charge gas temperatures and reacting sprays were performed using a high reactivity gasoline (research octane number 60) and ultra-low sulfur diesel. The experimental work were designed to isolate the effect of several important fuel properties on spray and combustion. The experimentally investigated spray combustion characteristics include spray dispersion, vapor penetration, liquid penetration, ignition, flame lift-off, and natural luminosity. These experiments provided evidence behind the lower particulate matter emissions benefit of gasoline. A transient spray cone angle correlation was developed based on the experimental measurements. The correlation was developed to improve the description of fuel-air mixing in computational fluid dynamic (CFD) simulations. The correlation was integrated with CFD simulations and the benefits of using a transient spray cone angle profile were demonstrated. Reacting spray CFD simulations were performed and validated extensively against the experimental spray characteristics on ignition, flame lift-off, soot natural luminosity, and external published local soot concentration measurements. The CFD simulations provided additional understanding of the soot emission processes to complement experimental measurements.

Download or read book Diesel Engine Transient Operation written by Constantine D. Rakopoulos and published by Springer Science & Business Media. This book was released on 2009-03-10 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditionally, the study of internal combustion engines operation has focused on the steady-state performance. However, the daily driving schedule of automotive and truck engines is inherently related to unsteady conditions. In fact, only a very small portion of a vehicle’s operating pattern is true steady-state, e. g. , when cruising on a motorway. Moreover, the most critical conditions encountered by industrial or marine engines are met during transients too. Unfortunately, the transient operation of turbocharged diesel engines has been associated with slow acceleration rate, hence poor driveability, and overshoot in particulate, gaseous and noise emissions. Despite the relatively large number of published papers, this very important subject has been treated in the past scarcely and only segmentally as regards reference books. Merely two chapters, one in the book Turbocharging the Internal Combustion Engine by N. Watson and M. S. Janota (McMillan Press, 1982) and another one written by D. E. Winterbone in the book The Thermodynamics and Gas Dynamics of Internal Combustion Engines, Vol. II edited by J. H. Horlock and D. E. Winterbone (Clarendon Press, 1986) are dedicated to transient operation. Both books, now out of print, were published a long time ago. Then, it seems reasonable to try to expand on these pioneering works, taking into account the recent technological advances and particularly the global concern about environmental pollution, which has intensified the research on transient (diesel) engine operation, typically through the Transient Cycles certification of new vehicles.

Download or read book Automotive Spark Ignited Direct Injection Gasoline Engines written by F. Zhao and published by Elsevier. This book was released on 2000-02-08 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: The process of fuel injection, spray atomization and vaporization, charge cooling, mixture preparation and the control of in-cylinder air motion are all being actively researched and this work is reviewed in detail and analyzed. The new technologies such as high-pressure, common-rail, gasoline injection systems and swirl-atomizing gasoline fuel injections are discussed in detail, as these technologies, along with computer control capabilities, have enabled the current new examination of an old objective; the direct-injection, stratified-charge (DISC), gasoline engine. The prior work on DISC engines that is relevant to current GDI engine development is also reviewed and discussed. The fuel economy and emission data for actual engine configurations have been obtained and assembled for all of the available GDI literature, and are reviewed and discussed in detail. The types of GDI engines are arranged in four classifications of decreasing complexity, and the advantages and disadvantages of each class are noted and explained. Emphasis is placed upon consensus trends and conclusions that are evident when taken as a whole; thus the GDI researcher is informed regarding the degree to which engine volumetric efficiency and compression ratio can be increased under optimized conditions, and as to the extent to which unburned hydrocarbon (UBHC), NOx and particulate emissions can be minimized for specific combustion strategies. The critical area of GDI fuel injector deposits and the associated effect on spray geometry and engine performance degradation are reviewed, and important system guidelines for minimizing deposition rates and deposit effects are presented. The capabilities and limitations of emission control techniques and after treatment hardware are reviewed in depth, and a compilation and discussion of areas of consensus on attaining European, Japanese and North American emission standards presented. All known research, prototype and production GDI engines worldwide are reviewed as to performance, emissions and fuel economy advantages, and for areas requiring further development. The engine schematics, control diagrams and specifications are compiled, and the emission control strategies are illustrated and discussed. The influence of lean-NOx catalysts on the development of late-injection, stratified-charge GDI engines is reviewed, and the relative merits of lean-burn, homogeneous, direct-injection engines as an option requiring less control complexity are analyzed.

Download or read book Theoretical and Numerical Combustion written by Thierry Poinsot and published by R.T. Edwards, Inc.. This book was released on 2005 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introducing numerical techniques for combustion, this textbook describes both laminar and turbulent flames, addresses the problem of flame-wall interaction, and presents a series of theoretical tools used to study the coupling phenomena between combustion and acoustics. The second edition incorporates recent advances in unsteady simulation methods,

Download or read book An Optical and Computational Investigation on the Effects of Transient Fuel Injections in Internal Combustion Engines written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of transient rate-of-injection profiles on high-pressure fuel jets have been studied in an optically accessible internal combustion engine. High-speed optical imaging measurements were applied over a range of ambient conditions, fuel types, and injection parameters. The optical data demonstrate that during the early part of the injection, while the liquid core of the jet is disintegrating, penetration is functionally linked to the orifice exit velocity up until a downstream distance hypothesized to be the jet breakup length. The jets then transition to a mixing dominated penetration behavior further downstream. Therefore, for cases that exhibit transient rate-of-injection (ROI) profiles, quasi-steady correlations for penetration have poor agreement with the empirical data. The lack of agreement between models using quasi-steady approximations and the high-speed experimental data, and the experimental evidence of liquid core physics impacting the transient jet penetration, motivated the development of a new 1-D model that integrates liquid core penetration physics and eliminates quasi-steady approximations. The new 1-D modeling methodology couples the transport equations for the evolution of the liquid core of the jet and the surrounding sheath of droplets resulting from breakup. The results of the model are validated against the aforementioned optical transient jet measurements. Finally, experimental results for two jet fuels and a diesel fuel are studied with the aid of the model. Differences in fuel properties cause the diesel fuel jet to transition from an incomplete spray to a complete spray later than the jet fuels during the transient injection process. Increasing ambient density causes the transition to happen earlier during the injection transient for all three fuels. The ignition delay and liftoff length appeared to be relatively unaffected by the late transition from incomplete to complete spray at low ambient density and low injection pressure. The results of the current study emphasize the importance of liquid core breakup on early jet penetration, and emphasize the need to consider the transition from incomplete to complete spray at low injection pressures and/or low ambient density with long transient ROIs to accurately model spray behavior.

Download or read book Fuel Spray Modeling for Compression Ignition Engine Configurations written by Krishna Latha Ankem and published by . This book was released on 2005 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Numerical Study on Ignition and Combustion Process of a Diesel Spray in EGR Environment written by Y. M. Kim and published by . This book was released on 1996 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Literature Abstracts written by Society of Automotive Engineers and published by . This book was released on 2000 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquid Sprays and Flow Studies in the Direct Injection Diesel Engine Under Motored Conditions written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-11-10 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: A two dimensional, implicit finite difference method of the control volume variety, a two equation model of turbulence, and a discrete droplet model were used to study the flow field, turbulence levels, fuel penetration, vaporization, and mixing in diesel engine environments. The model was also used to study the effects of engine speed, injection angle, spray cone angle, droplet distribution, and intake swirl angle on the flow field, spray penetration and vaporization, and turbulence in motored two-stroke diesel engines. It is shown that there are optimum conditions for injection, which depend on droplet distribution, swirl, spray cone angle, and injection angle. The optimum conditions result in good spray penetration and vaporization and in good fuel mixing. The calculation presented clearly indicates that internal combustion engine models can be used to assess, at least qualitatively, the effects of injection characteristics and engine operating conditions on the flow field and on the spray penetration and vaporization in diesel engines. Nguyen, Hung Lee and Carpenter, Mark H. and Ramos, Juan I. and Schock, Harold J. and Stegeman, James D. Glenn Research Center; Langley Research Center...

Download or read book Spray Ignition Measurements in a Constant Volume Combustion Vessel Under Engine relevant Conditions written by Varun Ramesh and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pressure-based and optical diagnostics for ignition delay (ID) measurement of a diesel spray from a multi-hole nozzle were investigated in a constant volume combustion vessel (CVCV) at conditions similar to those in a conventional diesel engine at the start of injection (SOI). It was first hypothesized that compared to an engine, the shorter ID in a CVCV was caused by NO, a byproduct of premixed combustion. The presence of a significant concentration of NO+NO2 was confirmed experimentally and by using a multi-zone model of premixed combustion. Experiments measuring the effect of NO on ID were performed at conditions relevant to a conventional diesel engine. Depending on the temperature regime and the nature of the fuel, NO addition was found to advance or retard ignition. Constant volume ignition simulations were capable of describing the observed trends; the magnitudes were different due to the physical processes involved in spray ignition, not modeled in the current study. The results of the study showed that ID is sensitive to low NO concentrations (

Download or read book A Numerical Study of the Transient Evaporating Spray Mixing Process in the Diesel Environment written by T.-W. Kuo and published by . This book was released on 1983 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1987 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: