Download or read book Thermodynamic and Chemical Kinetic Coupled Modeling for the Determination of Cyclic Combustion Phasing in HCCI Engines written by Krishawn Michele Goodwin and published by . This book was released on 2015 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: "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.

Download or read book Modeling and Analysis of an HCCI Engine During Thermal Transients Using a Thermodynamic Cycle Simulation with a Coupled Wall Thermal Network written by Kyoungjoon Chang and published by . This book was released on 2006 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermodynamic Based Modeling for Nonlinear Control of Combustion Phasing in HCCI Engines written by Joshua Bradley Bettis and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "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

Download or read book Modeling Engine Spray and Combustion Processes written by Gunnar Stiesch and published by Springer Science & Business Media. This book was released on 2003-04-10 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book An Introduction to Thermodynamic Cycle Simulations for Internal Combustion Engines written by Jerald A. Caton and published by John Wiley & Sons. This book was released on 2015-10-19 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Thermodynamic Analysis of Combustion Engines written by Ashley S. Campbell and published by John Wiley & Sons. This book was released on 1979-03-15 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Simulating Combustion written by Günter P. Merker and published by Springer Science & Business Media. This book was released on 2005-12-17 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book A Sequential Fluid mechanic Chemical kinetic Model of Propane HCCI Combustion written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Experimental and Kinetic Modeling Study of Cyclohexane and Its Mono alkylated Derivatives Combustion written by Zhandong Wang and published by Springer. This book was released on 2018-01-30 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Mixture Formation in Internal Combustion Engines written by Carsten Baumgarten and published by Springer Science & Business Media. This book was released on 2006-09-28 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Chemical Kinetic Models for HCCI and Diesel Combustion written by and published by . This book was released on 2008 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrocarbon fuels for advanced combustion engines consist of complex mixtures of hundreds or even thousands of different components. These components can be grouped into a number of chemically distinct classes, consisting of n-paraffins, branched paraffins, cyclic paraffins, olefins, oxygenates, and aromatics. Biodiesel contains its own unique chemical class called methyl esters. The fractional amounts of these chemical classes are quite different in gasoline, diesel fuel, oil-sand derived fuels and bio-derived fuels, which contributes to the very different combustion characteristics of each of these types of combustion systems. The objectives of this project are: (1) Develop detailed chemical kinetic models for fuel components used in surrogate fuels for diesel and HCCI engines; (2) Develop surrogate fuel models to represent real fuels and model low temperature combustion strategies in HCCI and diesel engines that lead to low emissions and high efficiency; and (3) Characterize the role of fuel composition on low temperature combustion modes of advanced combustion engines.

Download or read book Hcci and Cai Engines for the Automotive Industry written by H Zhao and published by Elsevier. This book was released on 2007-08-02 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Analysis of the Effect of Geometry Generated Turbulence on HCCI Combustion by Multi Zone Modeling written by M. Christensen and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper illustrates the applicability of a sequential fluid mechanics, multi-zone chemical kinetics model to analyze HCCI experimental data for two combustion chamber geometries with different levels of turbulence: a low turbulence disc geometry (flat top piston), and a high turbulence square geometry (piston with a square bowl). The model uses a fluid mechanics code to determine temperature histories in the engine as a function of crank angle. These temperature histories are then fed into a chemical kinetic solver, which determines combustion characteristics for a relatively small number of zones (40). The model makes the assumption that there is no direct linking between turbulence and combustion. The results show that the multi-zone model yields good results for both the disc and the square geometries. The model makes good predictions of pressure traces and heat release rates. The experimental results indicate that the high turbulence square geometry has longer burn duration than the low turbulence disc geometry. This difference can be explained by the sequential multi-zone model, which indicates that the cylinder with the square bowl has a thicker boundary layer that results in a broader temperature distribution. This broader temperature distribution tends to lengthen the combustion, as cold mass within the cylinder takes longer to reach ignition temperature when compressed by the expansion of the first burned gases. The multi-zone model, which makes the basic assumption that HCCI combustion is controlled by chemical kinetics, is therefore capable of explaining the experimental results obtained for different levels of turbulence, without considering a direct interaction between turbulence and combustion. A direct connection between turbulence and HCCI combustion may still exists, but it seems to play a relatively minor role in determining burn duration at the conditions analyzed in this paper.

Download or read book Inflation Kaufkraft Wechselkurs written by and published by . This book was released on 1986 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermodynamic chemical Kinetics Analysis of Detonation in Internal Combustion Engines written by Donald Richard Woods and published by . This book was released on 1949 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Investigation Into HCCI Combustion Under Primary Reference Fuel Blends written by Pablo Mendoza Villafuerte and published by . This book was released on 2009 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Homogeneous Charge Compression Ignition Engine with Emphasis on Combustion Timing and Reaction Rate written by Arunim Bhattacharya and published by . This book was released on 2017 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: HCCI engines are a class of engines which use high compression ratio to ignite a charge of air-fuel mixture, essentially eliminating the need for spark plugs. This contrasts with diesel engines (although HCCI can be used for diesel engines) where the fuel is injected near the top dead center of the compression stroke regime. Gasoline HCCI engines are of significance because, it attempts to improve the characteristics of the engine for example the thermal efficiency. High compression ratio comes with higher thermal efficiency, yet the peak temperature remains low enough to have low production rates of harmful oxides of nitrogen and formation of soot. However, there are certain challenges associated with such type of engine, one of which and perhaps the most important of all is how to control the combustion rate. Flow dynamics and chemical-kinetics analysis, is essential to predict combustion timing, duration, and rate. The objective of this study is to analyze a HCCI engine using, simulation analysis models including a three-dimensional CFD simulation model. Simulation analysis is carried out using a generic HCCI engine, initially with simplified chemical kinetics, and then using detailed chemical kinetics and using RANS turbulence CFD model. A sensitivity analysis of the effect of RPM on the combustion time, burn duration, heat release, efficiency and emission concentration are carried out.