A Detailed Multi-Zone Thermodynamic Simulation For Direct-Injection Diesel Engine Combustion

A Detailed Multi-Zone Thermodynamic Simulation For Direct-Injection Diesel Engine Combustion PDF Author: Xingyu Xue
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A detailed multi-zone thermodynamic simulation has been developed for the direct-injection (DI) diesel engine combustion process. For the purpose of predicting heterogeneous type combustion systems, the model explores the formation of pre-ignition radicals, start of combustion, and eventual heat release. These mechanisms are described based on the current understanding and knowledge of the diesel engine combustion acquired through advanced laser-based diagnostics. Six zones are developed to take into account the surrounding bulk gas, liquid- and vapor-phase fuel, pre-ignition mixing, fuel-rich combustion products as well as the diffusion flame combustion products. A three-step phenomenological soot model and a nitric oxide emission model are applied based on where and when each of these reactions mainly occurs within the diesel fuel jet evolution process. The simulation is completed for a 4.5 liter, inline four-cylinder diesel engine for a range of operating conditions. Specifically, the engine possesses a compression ratio of 16.6, and has a bore and stroke of 106 and 127 mm. The results suggest that the simulation is able to accurately reproduce the fuel jet evolution and heat release process for conventional diesel engine combustion conditions. The soot and nitric oxide models are able to qualitatively predict the effects of various engine parameters on the engine-out emissions. In particular, the detailed thermodynamics and characteristics with respect to the combustion and emission formation processes are investigated for different engine speed/loads, injection pressures and timings, and EGR levels. The local thermodynamic properties and energy, mass distributions obtained from the simulation offer some fundamental insights into heterogeneous type combustion systems. The current work provides opportunities to better study and understand the diesel engine combustion and emission formation mechanisms for conventional diesel engine combustion modes. The flexible, low computational cost features of this simulation result in a convenient tool for conducting parametric studies, and benefits for engine control and diagnostics. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148225

A Detailed Multi-Zone Thermodynamic Simulation For Direct-Injection Diesel Engine Combustion

A Detailed Multi-Zone Thermodynamic Simulation For Direct-Injection Diesel Engine Combustion PDF Author: Xingyu Xue
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A detailed multi-zone thermodynamic simulation has been developed for the direct-injection (DI) diesel engine combustion process. For the purpose of predicting heterogeneous type combustion systems, the model explores the formation of pre-ignition radicals, start of combustion, and eventual heat release. These mechanisms are described based on the current understanding and knowledge of the diesel engine combustion acquired through advanced laser-based diagnostics. Six zones are developed to take into account the surrounding bulk gas, liquid- and vapor-phase fuel, pre-ignition mixing, fuel-rich combustion products as well as the diffusion flame combustion products. A three-step phenomenological soot model and a nitric oxide emission model are applied based on where and when each of these reactions mainly occurs within the diesel fuel jet evolution process. The simulation is completed for a 4.5 liter, inline four-cylinder diesel engine for a range of operating conditions. Specifically, the engine possesses a compression ratio of 16.6, and has a bore and stroke of 106 and 127 mm. The results suggest that the simulation is able to accurately reproduce the fuel jet evolution and heat release process for conventional diesel engine combustion conditions. The soot and nitric oxide models are able to qualitatively predict the effects of various engine parameters on the engine-out emissions. In particular, the detailed thermodynamics and characteristics with respect to the combustion and emission formation processes are investigated for different engine speed/loads, injection pressures and timings, and EGR levels. The local thermodynamic properties and energy, mass distributions obtained from the simulation offer some fundamental insights into heterogeneous type combustion systems. The current work provides opportunities to better study and understand the diesel engine combustion and emission formation mechanisms for conventional diesel engine combustion modes. The flexible, low computational cost features of this simulation result in a convenient tool for conducting parametric studies, and benefits for engine control and diagnostics. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148225

Modelling Diesel Combustion

Modelling Diesel Combustion PDF Author: P. A. Lakshminarayanan
Publisher: Springer Science & Business Media
ISBN: 904813885X
Category : Technology & Engineering
Languages : en
Pages : 313

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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.

A Multi-zone Direct-injection Diesel Spray Combustion Model for Cycle Simulation Studies of Large-bore Engine Performance and Emissions

A Multi-zone Direct-injection Diesel Spray Combustion Model for Cycle Simulation Studies of Large-bore Engine Performance and Emissions PDF Author: Dohoy Jung
Publisher:
ISBN:
Category : Mechanical engineering
Languages : en
Pages : 330

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Book Description


Mixture Formation in Internal Combustion Engines

Mixture Formation in Internal Combustion Engines PDF Author: Carsten Baumgarten
Publisher: Springer Science & Business Media
ISBN: 3540308369
Category : Technology & Engineering
Languages : en
Pages : 312

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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.

Simulating Combustion

Simulating Combustion PDF Author: Günter P. Merker
Publisher: Springer Science & Business Media
ISBN: 3540306269
Category : Technology & Engineering
Languages : en
Pages : 424

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Book Description
The numerical simulation of combustion processes in internal combustion engines, including also the formation of pollutants, has become increasingly important in the recent years, and today the simulation of those processes has already become an indispensable tool when - veloping new combustion concepts. While pure thermodynamic models are well-established tools that are in use for the simulation of the transient behavior of complex systems for a long time, the phenomenological models have become more important in the recent years and have also been implemented in these simulation programs. In contrast to this, the thr- dimensional simulation of in-cylinder combustion, i. e. the detailed, integrated and continuous simulation of the process chain injection, mixture formation, ignition, heat release due to combustion and formation of pollutants, has been significantly improved, but there is still a number of challenging problems to solve, regarding for example the exact description of s- processes like the structure of turbulence during combustion as well as the appropriate choice of the numerical grid. While chapter 2 includes a short introduction of functionality and operating modes of internal combustion engines, the basics of kinetic reactions are presented in chapter 3. In chapter 4 the physical and chemical processes taking place in the combustion chamber are described. Ch- ter 5 is about phenomenological multi-zone models, and in chapter 6 the formation of poll- ants is described.

Modeling Engine Spray and Combustion Processes

Modeling Engine Spray and Combustion Processes PDF Author: Gunnar Stiesch
Publisher: Springer Science & Business Media
ISBN: 9783540006824
Category : Computers
Languages : en
Pages : 314

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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.

Development of a Partially Premixed Combustion Model for a Diesel Engine Using Multiple Injection Strategies

Development of a Partially Premixed Combustion Model for a Diesel Engine Using Multiple Injection Strategies PDF Author: Rene Thygesen
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832530932
Category : Science
Languages : en
Pages : 157

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Book Description
In order to fulfil future emissions legislations, new combustion systems are to be investigated. One way of improving exhaust emissions is the application of multiple injection strategies and conventional or partially premixed combustion conditions to a Diesel engine. The application of numerical techniques as CFD supports and improves the quality of engine developments. Unfortunately, current spray and combustion models are not accurate enough to simulate multiple injection systems, being in this way a topic of research. The goal of this study was the development of a novel simulation method for the investigation of Diesel engines operated with multiple injection strategies and different combustion modes. The first part of this work focused in improving the spray modelling. The inform ation of 3D CFD simulations of the injector nozzle was introduced in the spray simulation as boundary conditions developing coupling subroutines for this issue. The atomisation modelling was also improved using validated presumed droplet size distributions. Moreover, to avoid the simulation of the injector nozzle for every investigated operating point, a novel interpolating tool was developed in order to create spray boundary conditions based on few 3D CFD simulations of the nozzle under certain initial and boundary conditions. The second part of this thesis dealt with the combustion modelling of Diesel engines. For this issue, a laminar flamelet approach called Representative Interactive Flamelet model (RIF) was selected and implemented. Afterwards, an extended combustion model based on RIF was developed in order to take into account multiple injection strategies. Finally, this new model was validated with a wide range of operating points: applying multiple injection strategies under conventional and partially premixed combustion conditions.

Advances in IC Engines and Combustion Technology

Advances in IC Engines and Combustion Technology PDF Author: Ashwani K. Gupta
Publisher: Springer Nature
ISBN: 9811559961
Category : Technology & Engineering
Languages : en
Pages : 939

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Book Description
This book comprises select peer-reviewed proceedings of the 26th National Conference on IC Engines and Combustion (NCICEC) 2019 which was organised by the Department of Mechanical Engineering, National Institute of Technology Kurukshetra under the aegis of The Combustion Institute-Indian Section (CIIS). The book covers latest research and developments in the areas of combustion and propulsion, exhaust emissions, gas turbines, hybrid vehicles, IC engines, and alternative fuels. The contents include theoretical and numerical tools applied to a wide range of combustion problems, and also discusses their applications. This book can be a good reference for engineers, educators and researchers working in the area of IC engines and combustion.

Introduction to Modeling and Control of Internal Combustion Engine Systems

Introduction to Modeling and Control of Internal Combustion Engine Systems PDF Author: Lino Guzzella
Publisher: Springer Science & Business Media
ISBN: 3662080036
Category : Technology & Engineering
Languages : en
Pages : 303

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Book Description
Internal combustion engines still have a potential for substantial improvements, particularly with regard to fuel efficiency and environmental compatibility. These goals can be achieved with help of control systems. Modeling and Control of Internal Combustion Engines (ICE) addresses these issues by offering an introduction to cost-effective model-based control system design for ICE. The primary emphasis is put on the ICE and its auxiliary devices. Mathematical models for these processes are developed in the text and selected feedforward and feedback control problems are discussed. The appendix contains a summary of the most important controller analysis and design methods, and a case study that analyzes a simplified idle-speed control problem. The book is written for students interested in the design of classical and novel ICE control systems.

Simulating Combustion

Simulating Combustion PDF Author: Günter Merker
Publisher: Springer
ISBN: 9783540251613
Category : Technology & Engineering
Languages : en
Pages : 402

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Book Description
The numerical simulation of combustion processes in internal combustion engines, including also the formation of pollutants, has become increasingly important in the recent years, and today the simulation of those processes has already become an indispensable tool when - veloping new combustion concepts. While pure thermodynamic models are well-established tools that are in use for the simulation of the transient behavior of complex systems for a long time, the phenomenological models have become more important in the recent years and have also been implemented in these simulation programs. In contrast to this, the thr- dimensional simulation of in-cylinder combustion, i. e. the detailed, integrated and continuous simulation of the process chain injection, mixture formation, ignition, heat release due to combustion and formation of pollutants, has been significantly improved, but there is still a number of challenging problems to solve, regarding for example the exact description of s- processes like the structure of turbulence during combustion as well as the appropriate choice of the numerical grid. While chapter 2 includes a short introduction of functionality and operating modes of internal combustion engines, the basics of kinetic reactions are presented in chapter 3. In chapter 4 the physical and chemical processes taking place in the combustion chamber are described. Ch- ter 5 is about phenomenological multi-zone models, and in chapter 6 the formation of poll- ants is described.