Thermodynamic and Chemical Kinetic Coupled Modeling for the Determination of Cyclic Combustion Phasing in HCCI Engines

Thermodynamic and Chemical Kinetic Coupled Modeling for the Determination of Cyclic Combustion Phasing in HCCI Engines PDF Author: Krishawn Michele Goodwin
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 171

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Book Description
"Homogeneous charge compression ignition (HCCI) is a low temperature combustion mode that contains great potential for decreasing emissions while increasing efficiency in internal combustion engines. The limitation is in that it is inherently difficult to control based on the lack of an external combustion trigger. This thesis outlines the potential of using the combustion residual species of carbon monoxide as a method of controlling the location of combustion by using data from a computer model. The model is a nonlinear five-state thermodynamic model that is coupled with a skeletal chemical kinetic model for PRF96. The model computes the amount of carbon monoxide within the cylinder during partial burn, which is when the engine is most difficult to control, and also calculates the amount of carbon monoxide residual that will be fed forward into the next cycle. The model is verified by comparing experimental data at the steady state and at the onset of partial burn collected from a Hatz 1D50Z engine located on the Missouri S&T campus. The impact of the carbon monoxide on the cyclic dynamics of the engine is observed through return maps displaying cyclic dependence generated by using data from the model. These return maps are created to determine the effects of the naturally produced amounts of carbon monoxide during partial burn, artificially increased amount of carbon monoxide during partial burn and complete combustion, and the effects of the intake temperature on several important engine parameters. These effects observed can be used to determine the relevance of using carbon monoxide as a control for HCCI."--Abstract, page iii.

Thermodynamic and Chemical Kinetic Coupled Modeling for the Determination of Cyclic Combustion Phasing in HCCI Engines

Thermodynamic and Chemical Kinetic Coupled Modeling for the Determination of Cyclic Combustion Phasing in HCCI Engines PDF Author: Krishawn Michele Goodwin
Publisher:
ISBN:
Category : Carbon monoxide
Languages : en
Pages : 171

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Book Description
"Homogeneous charge compression ignition (HCCI) is a low temperature combustion mode that contains great potential for decreasing emissions while increasing efficiency in internal combustion engines. The limitation is in that it is inherently difficult to control based on the lack of an external combustion trigger. This thesis outlines the potential of using the combustion residual species of carbon monoxide as a method of controlling the location of combustion by using data from a computer model. The model is a nonlinear five-state thermodynamic model that is coupled with a skeletal chemical kinetic model for PRF96. The model computes the amount of carbon monoxide within the cylinder during partial burn, which is when the engine is most difficult to control, and also calculates the amount of carbon monoxide residual that will be fed forward into the next cycle. The model is verified by comparing experimental data at the steady state and at the onset of partial burn collected from a Hatz 1D50Z engine located on the Missouri S&T campus. The impact of the carbon monoxide on the cyclic dynamics of the engine is observed through return maps displaying cyclic dependence generated by using data from the model. These return maps are created to determine the effects of the naturally produced amounts of carbon monoxide during partial burn, artificially increased amount of carbon monoxide during partial burn and complete combustion, and the effects of the intake temperature on several important engine parameters. These effects observed can be used to determine the relevance of using carbon monoxide as a control for HCCI."--Abstract, page iii.

Modeling and Analysis of an HCCI Engine During Thermal Transients Using a Thermodynamic Cycle Simulation with a Coupled Wall Thermal Network

Modeling and Analysis of an HCCI Engine During Thermal Transients Using a Thermodynamic Cycle Simulation with a Coupled Wall Thermal Network PDF Author: Kyoungjoon Chang
Publisher:
ISBN:
Category :
Languages : en
Pages : 440

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Book Description


Thermodynamic Based Modeling for Nonlinear Control of Combustion Phasing in HCCI Engines

Thermodynamic Based Modeling for Nonlinear Control of Combustion Phasing in HCCI Engines PDF Author: Joshua Bradley Bettis
Publisher:
ISBN:
Category : Chemical kinetics
Languages : en
Pages : 0

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Book Description
"Low temperature combustion modes, such as Homogeneous Charge Compression Ignition (HCCI), represent a promising means to increase the efficiency and significantly reduce the emissions of internal combustion engines. Implementation and control are difficult, however, due to the lack of an external combustion trigger. This thesis outlines a nonlinear control-oriented model of a single cylinder HCCI engine, which is physically based on a five state thermodynamic cycle. This model is aimed at capturing the behavior of an engine which utilizes fully vaporized gasoline-type fuels, exhaust gas recirculation and intake air heating in order to achieve HCCI operation. The onset of combustion, which is vital for control, is modeled using an Arrhenius Reaction Rate expression which relates the combustion timing to both charge dilution and temperature. To account for a finite HCCI combustion event, the point of constant volume combustion is shifted for SOC to a point of high energy release based on experimental heat release data. The model is validated against experimental data form a single cylinder CI engine operating under HCCI conditions at two different fueling rates. Parameters relevant to control such as combustion timing agree very well with the experiment at both operating conditions. The extension of the model to other fuels is also investigated via the Octane Index (OI) of several different gasoline-type fuels. Since this nonlinear model is developed from a controls perspective, both the output and state update equations are formulated such that they are functions of only the control inputs and state variables, therefore making them directly applicable to state space methods for control. The result is a discrete-time nonlinear control model which provides a platform for developing and validating various nonlinear control strategies"--Abstract, leaf iv

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.

An Introduction to Thermodynamic Cycle Simulations for Internal Combustion Engines

An Introduction to Thermodynamic Cycle Simulations for Internal Combustion Engines PDF Author: Jerald A. Caton
Publisher: John Wiley & Sons
ISBN: 1119037565
Category : Technology & Engineering
Languages : en
Pages : 381

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Book Description
This book provides an introduction to basic thermodynamic engine cycle simulations, and provides a substantial set of results. Key features includes comprehensive and detailed documentation of the mathematical foundations and solutions required for thermodynamic engine cycle simulations. The book includes a thorough presentation of results based on the second law of thermodynamics as well as results for advanced, high efficiency engines. Case studies that illustrate the use of engine cycle simulations are also provided.

Thermodynamic Analysis of Combustion Engines

Thermodynamic Analysis of Combustion Engines PDF Author: Ashley S. Campbell
Publisher: John Wiley & Sons
ISBN:
Category : Science
Languages : en
Pages : 388

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Book Description
Intended for a second course in thermodynamics. Explains in detail how the analysis of each engine system can be formulated for a computer program. Examines all present day engines which operate on the internal combustion system, including gas turbines, two-stroke and four-stroke internal combustion engines, both Otto and Diesel cycles, liquid propellant rockets, free piston engines, and powders in guns. Includes chemical equilibrium, explaining how equilibrium compositions in multireaction systems can be calculated. Uses SI units exclusively.

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.

A Sequential Fluid-mechanic Chemical-kinetic Model of Propane HCCI Combustion

A Sequential Fluid-mechanic Chemical-kinetic Model of Propane HCCI Combustion PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We have developed a methodology for predicting combustion and emissions in a Homogeneous Charge Compression Ignition (HCCI) Engine. This methodology combines a detailed fluid mechanics code with a detailed chemical kinetics code. Instead of directly linking the two codes, which would require an extremely long computational time, the methodology consists of first running the fluid mechanics code to obtain temperature profiles as a function of time. These temperature profiles are then used as input to a multi-zone chemical kinetics code. The advantage of this procedure is that a small number of zones (10) is enough to obtain accurate results. This procedure achieves the benefits of linking the fluid mechanics and the chemical kinetics codes with a great reduction in the computational effort, to a level that can be handled with current computers. The success of this procedure is in large part a consequence of the fact that for much of the compression stroke the chemistry is inactive and thus has little influence on fluid mechanics and heat transfer. Then, when chemistry is active, combustion is rather sudden, leaving little time for interaction between chemistry and fluid mixing and heat transfer. This sequential methodology has been capable of explaining the main characteristics of HCCI combustion that have been observed in experiments. In this paper, we use our model to explore an HCCI engine running on propane. The paper compares experimental and numerical pressure traces, heat release rates, and hydrocarbon and carbon monoxide emissions. The results show an excellent agreement, even in parameters that are difficult to predict, such as chemical heat release rates. Carbon monoxide emissions are reasonably well predicted, even though it is intrinsically difficult to make good predictions of CO emissions in HCCI engines. The paper includes a sensitivity study on the effect of the heat transfer correlation on the results of the analysis. Importantly, the paper also shows a numerical study on how parameters such as swirl rate, crevices and ceramic walls could help in reducing HC and CO emissions from HCCI engines.

Hcci and Cai Engines for the Automotive Industry

Hcci and Cai Engines for the Automotive Industry PDF Author: H Zhao
Publisher: Elsevier
ISBN: 184569354X
Category : Technology & Engineering
Languages : en
Pages : 557

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Book Description
Homogeneous charge compression ignition (HCCI)/controlled auto-ignition (CAI) has emerged as one of the most promising engine technologies with the potential to combine fuel efficiency and improved emissions performance, offering reduced nitrous oxides and particulate matter alongside efficiency comparable with modern diesel engines. Despite the considerable advantages, its operational range is rather limited and controlling the combustion (timing of ignition and rate of energy release) is still an area of on-going research. Commercial applications are, however, close to reality.HCCI and CAI engines for the automotive industry presents the state-of-the-art in research and development on an international basis, as a one-stop reference work. The background to the development of HCCI / CAI engine technology is described. Basic principles, the technologies and their potential applications, strengths and weaknesses, as well as likely future trends and sources of further information are reviewed in the areas of gasoline HCCI / CAI engines; diesel HCCI engines; HCCI / CAI engines with alternative fuels; and advanced modelling and experimental techniques. The book provides an invaluable source of information for scientific researchers, R&D engineers and managers in the automotive engineering industry worldwide. - Presents the state-of-the-art in research and development on an international basis - An invaluable source of information for scientific researchers, R&D engineers and managers in the automotive engineering industry worldwide - Looks at one of the most promising engine technologies around

Experimental and Kinetic Modeling Study of Cyclohexane and Its Mono-alkylated Derivatives Combustion

Experimental and Kinetic Modeling Study of Cyclohexane and Its Mono-alkylated Derivatives Combustion PDF Author: Zhandong Wang
Publisher: Springer
ISBN: 9789811056925
Category : Science
Languages : en
Pages : 216

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Book Description
This thesis investigates the combustion chemistry of cyclohexane, methylcyclohexane, and ethylcyclohexane on the basis of state-of-the-art synchrotron radiation photoionization mass spectrometry experiments, quantum chemistry calculations, and extensive kinetic modeling. It explores the initial decomposition mechanism and distribution of the intermediates, proposes a novel formation mechanism of aromatics, and develops a detailed kinetic model to predict the three cycloalkanes’ combustion properties under a wide range of conditions. Accordingly, the thesis provides an essential basis for studying much more complex cycloalkanes in transport fuels and has applications in engine and fuel design, as well as emission control.