Download or read book Numerical Approaches to Combustion Modeling written by and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Combustion Modeling written by Tarek Echekki and published by Springer Science & Business Media. This book was released on 2010-12-25 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent combustion sits at the interface of two important nonlinear, multiscale phenomena: chemistry and turbulence. Its study is extremely timely in view of the need to develop new combustion technologies in order to address challenges associated with climate change, energy source uncertainty, and air pollution. Despite the fact that modeling of turbulent combustion is a subject that has been researched for a number of years, its complexity implies that key issues are still eluding, and a theoretical description that is accurate enough to make turbulent combustion models rigorous and quantitative for industrial use is still lacking. In this book, prominent experts review most of the available approaches in modeling turbulent combustion, with particular focus on the exploding increase in computational resources that has allowed the simulation of increasingly detailed phenomena. The relevant algorithms are presented, the theoretical methods are explained, and various application examples are given. The book is intended for a relatively broad audience, including seasoned researchers and graduate students in engineering, applied mathematics and computational science, engine designers and computational fluid dynamics (CFD) practitioners, scientists at funding agencies, and anyone wishing to understand the state-of-the-art and the future directions of this scientifically challenging and practically important field.
Download or read book Numerical Approaches to Combustion Modeling written by Elaine S. Oran and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 1991 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Simulation of Turbulent Combustion written by Santanu De and published by Springer. This book was released on 2017-12-12 with total page 663 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive review of state-of-the-art models for turbulent combustion, with special emphasis on the theory, development and applications of combustion models in practical combustion systems. It simplifies the complex multi-scale and nonlinear interaction between chemistry and turbulence to allow a broader audience to understand the modeling and numerical simulations of turbulent combustion, which remains at the forefront of research due to its industrial relevance. Further, the book provides a holistic view by covering a diverse range of basic and advanced topics—from the fundamentals of turbulence–chemistry interactions, role of high-performance computing in combustion simulations, and optimization and reduction techniques for chemical kinetics, to state-of-the-art modeling strategies for turbulent premixed and nonpremixed combustion and their applications in engineering contexts.
Download or read book Numerical Simulations of Turbulent Combustion written by Andrei Lipatnikov and published by Mdpi AG. This book was released on 2020-07 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent burning of gaseous fuels is widely used for energy conversion in stationary power generation, e.g., gas turbines, land transportation, piston engines, and aviation, and aero-engine afterburners. Nevertheless, our fundamental understanding of turbulent combustion is still limited, because it is a highly non-linear and multiscale process that involves various local phenomena and thousands (e.g., for gasoline-air mixtures) of chemical reactions between hundreds of species, including several reactions that control emissions from flames. Therefore, there is a strong need for elaborating high fidelity, advanced numerical models, and methods that will catch the governing physical mechanisms of flame-turbulence interaction and, consequently, will make turbulent combustion computations an efficient predictive tool for applied research and, in particular, for development of a new generation of ultra-clean and highly efficient internal combustion engines that will allow society to properly respond to current environmental and efficiency challenges. Accordingly, papers published in this Special Issue (i) contribute to our fundamental understanding of flame-turbulence interaction by analyzing results of unsteady multi-dimensional numerical simulations and (ii) develop and validate high-fidelity models and efficient numerical methods for computational fluid Dynamics research into turbulent combustion in laboratory burners and engines.
Download or read book Data Analysis for Direct Numerical Simulations of Turbulent Combustion written by Heinz Pitsch and published by Springer Nature. This book was released on 2020-05-28 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents methodologies for analysing large data sets produced by the direct numerical simulation (DNS) of turbulence and combustion. It describes the development of models that can be used to analyse large eddy simulations, and highlights both the most common techniques and newly emerging ones. The chapters, written by internationally respected experts, invite readers to consider DNS of turbulence and combustion from a formal, data-driven standpoint, rather than one led by experience and intuition. This perspective allows readers to recognise the shortcomings of existing models, with the ultimate goal of quantifying and reducing model-based uncertainty. In addition, recent advances in machine learning and statistical inferences offer new insights on the interpretation of DNS data. The book will especially benefit graduate-level students and researchers in mechanical and aerospace engineering, e.g. those with an interest in general fluid mechanics, applied mathematics, and the environmental and atmospheric sciences.
Download or read book Numerical Modeling In Combustion written by T. J. Chung and published by CRC Press. This book was released on 1993-06-01 with total page 573 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes different numerical methods for applications in three particular fields: laminar flames, turbulent flames, and spray droplet combustion. It begins with an introduction on numerical modeling and general forms of governing equations in combustion. It also introduces options of numerical techniques to solve reactive flow problems in general, and combustion problems in particular. Basic numerical strategies are discussed, and certain example problems are selected for evaluation of the numerical methods and physical aspects of combustion.
Download or read book Turbulent Combustion written by Norbert Peters and published by Cambridge University Press. This book was released on 2000-08-15 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combustion of fossil fuels remains a key technology for the foreseeable future. It is therefore important that we understand the mechanisms of combustion and, in particular, the role of turbulence within this process. Combustion always takes place within a turbulent flow field for two reasons: turbulence increases the mixing process and enhances combustion, but at the same time combustion releases heat which generates flow instability through buoyancy, thus enhancing the transition to turbulence. The four chapters of this book present a thorough introduction to the field of turbulent combustion. After an overview of modeling approaches, the three remaining chapters consider the three distinct cases of premixed, non-premixed, and partially premixed combustion, respectively. This book will be of value to researchers and students of engineering and applied mathematics by demonstrating the current theories of turbulent combustion within a unified presentation of the field.
Download or read book A Novel Method in Combustion Modeling for 2D Numerical Study of a Two stage Porous Burner written by Mohammad Dabbagh and published by . This book was released on 2017 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive and Convergent Methods for Large Eddy Simulation of Turbulent Combustion written by Colin Russell Heye and published by . This book was released on 2014 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the recent past, LES methodology has emerged as a viable tool for modeling turbulent combustion. LES computes the large scale mixing process accurately, thereby providing a better starting point for small-scale models that describe the combustion process. Significant effort has been made over past decades to improve accuracy and applicability of the LES approach to a wide range of flows, though the current conventions often lack consistency to the problems at hand. To this end, the two main objectives of this dissertation are to develop a dynamic transport equation-based combustion model for large- eddy simulation (LES) of turbulent spray combustion and to investigate grid- independent LES modeling for scalar mixing. Long-standing combustion modeling approaches have shown to be suc- cessful for a wide range of gas-phase flames, however, the assumptions required to derive these formulations are invalidated in the presence of liquid fuels and non-negligible evaporation rates. In the first part of this work, a novel ap- proach is developed to account for these evaporation effects and the resulting multi-regime combustion process. First, the mathematical formulation is de- rived and the numerical implementation in a low-Mach number computational solver is verified against one-dimensional and lab scale, both non-reacting and reacting spray-laden flows. In order to clarify the modeling requirements in LES for spray combustion applications, results from a suite of fully-resolved direct numerical simulations (DNS) of a spray laden planar jet flame are fil- tered at a range of length scales. LES results are then validated against two sets of experimental jet flames, one having a pilot and allowing for reduced chemistry modeling and the second requiring the use of detail chemistry with in situ tabulation to reduce the computational cost of the direct integration of a chemical mechanism. The conventional LES governing equations are derived from a low-pass filtering of the Navier-Stokes equations. In practice, the filter used to derive the LES governing equations is not formally defined and instead, it is assumed that the discretization of LES equations will implicitly act as a low-pass filter. The second part of this study investigates an alternative derivation of the LES governing equations that requires the formal definition of the filtering operator, known as explicitly filtered LES. It has been shown that decoupling the filter- ing operation from the underlying grid allows for the isolation of subfilter-scale modeling errors from numerical discretization errors. Specific to combustion modeling are the aggregate errors associated with modeling sub-filter distribu- tions of scalars that are transported by numerical impacted turbulent fields. Quantities of interest to commonly-used combustion models, including sub- filter scalar variance and filtered scalar dissipation rate, are investigated for both homogeneous and shear-driven turbulent mixing.
Download or read book Numerical Modeling of Combustion Problems with Adaptive Grid Methods written by Farhad Raiszadeh and published by . This book was released on 1981 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Techniques for Direct and Large Eddy Simulations written by Xi Jiang and published by CRC Press. This book was released on 2016-04-19 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compared to the traditional modeling of computational fluid dynamics, direct numerical simulation (DNS) and large-eddy simulation (LES) provide a very detailed solution of the flow field by offering enhanced capability in predicting the unsteady features of the flow field. In many cases, DNS can obtain results that are impossible using any other me
Download or read book Turbulent Combustion Modeling written by Tarek Echekki and published by Springer. This book was released on 2011-04-09 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent combustion sits at the interface of two important nonlinear, multiscale phenomena: chemistry and turbulence. Its study is extremely timely in view of the need to develop new combustion technologies in order to address challenges associated with climate change, energy source uncertainty, and air pollution. Despite the fact that modeling of turbulent combustion is a subject that has been researched for a number of years, its complexity implies that key issues are still eluding, and a theoretical description that is accurate enough to make turbulent combustion models rigorous and quantitative for industrial use is still lacking. In this book, prominent experts review most of the available approaches in modeling turbulent combustion, with particular focus on the exploding increase in computational resources that has allowed the simulation of increasingly detailed phenomena. The relevant algorithms are presented, the theoretical methods are explained, and various application examples are given. The book is intended for a relatively broad audience, including seasoned researchers and graduate students in engineering, applied mathematics and computational science, engine designers and computational fluid dynamics (CFD) practitioners, scientists at funding agencies, and anyone wishing to understand the state-of-the-art and the future directions of this scientifically challenging and practically important field.
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 A Reacting Jet Direct Numerical Simulation for Assessing Combustion Model Error written by Bryan William Reuter and published by . This book was released on 2021 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: The simulation of turbulent combustion systems is a vital tool in the design and development of new technologies for power generation, transportation, defense applications, and industrial heating. In an engineering design cycle, modeling realistic device configurations in a cost- and time-effective manner is required. Due to their flexibility and computational tractability, Reynolds-Averaged Navier-Stokes (RANS)-based models are most commonly used for these purposes. However, these models are known to be inadequate. Turbulent combustion is the coupling of two multiscale, nonlinear phenomena which individually have many modeling challenges. Hence, it is unsurprising that the modeling ansatzes and simplifying assumptions which lead to these practical RANS-based models are suspect. Since RANS-based models will continue to be the dominant tool for turbulent combustion simulation, it is necessary to improve their predictivity through a better understanding of their deficiencies. The are three main modeling issues for turbulent combustion: modeling the turbulent flow, representing the chemical reactions, and capturing the interaction between the turbulence and the chemistry. Model errors can easily be conflated when attempting to quantify deficiencies in this multiphysics context where many individual models are coupled. This work introduces a new technique for isolating these errors through the creation of a flamelet-based direct numerical simulation (DNS) of a nonpremixed, temporally-evolving, planar, reacting jet. DNS is a technique which resolves all lengthscales and timescales of the turbulent flow, providing high-quality data for model development but at a significant computational cost. In the turbulent combustion context, the turbulence-chemistry interaction is also fully resolved. By closing the DNS with a steady laminar flamelet representation, a typical chemical reactions model for RANS-based simulations, RANS turbulence closures and turbulence-chemistry interaction models can be evaluated in isolation through a priori testing. Conversely, by comparing the flamelet DNS to a second DNS employing a higher-fidelity chemistry model, the flamelet closure and its impact on the flame's evolution can be interrogated directly. To obtain the DNS data, a novel algorithm for solving the variable-density, low-Mach Navier-Stokes equations extending the method of Kim, Moin, and Moser for incompressible flow is detailed here. It is a pseudospectral Fourier/B-spline collocation approach which obtains second order accuracy in time and numerical stability for large density ratios with an efficient, matrix-free, iterative treatment of the scalar equations. The a posteriori comparisons of the flamelet DNS and the complex chemistry DNS suggest the flamelet model can significantly alter the evolution of the mean state of the reacting jet; however, violations of global conservation were identified in the complex chemistry DNS. Therefore, no strong conclusions can be made about the chemical reactions model from the comparisons. Significant shortcomings have been identified in the a priori evaluations of the aforementioned RANS closures for turbulent transport, scalar mixing, and turbulence-chemistry interaction, where the flamelet model is taken to be exact. Finally, a flawed assumption in the steady laminar flamelet approach has been directly linked to nonphysical behavior of the density for small values of the scalar dissipation rate
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 2013-06-29 with total page 293 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 Numerical Investigations of Combustion written by Alexandre M Afonso and published by Mdpi AG. This book was released on 2022-08-19 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Special Issue will highlight the latest advances in numerical modeling of combustion-related applications. With the recent advancements in computational capacities and the widespread use of simulations in engineering problems, numerical methods are becoming increasingly important to improve existing models and develop new models that can help researchers to better understand the underlying mechanisms of combustion, their interaction with other physical phenomena, such as turbulence, and their impacts on the performance of related applications at both fundamental and practical levels.
