Download or read book Scalar Transport and Flamelet Modelling in Turbulent Jet Diffusion Flames written by Johannes P. Sanders and published by . This book was released on 1994 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 Flamelet Modelling for Partially Premixed Turbulent Jet Diffusion Flames written by Roy Ovink and published by . This book was released on 1999 with total page 171 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 Turbulent Premixed Flames written by Nedunchezhian Swaminathan and published by Cambridge University Press. This book was released on 2011-04-25 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: A work on turbulent premixed combustion is important because of increased concern about the environmental impact of combustion and the search for new combustion concepts and technologies. An improved understanding of lean fuel turbulent premixed flames must play a central role in the fundamental science of these new concepts. Lean premixed flames have the potential to offer ultra-low emission levels, but they are notoriously susceptible to combustion oscillations. Thus, sophisticated control measures are inevitably required. The editors' intent is to set out the modeling aspects in the field of turbulent premixed combustion. Good progress has been made on this topic, and this cohesive volume contains contributions from international experts on various subtopics of the lean premixed flame problem.
Download or read book Flamelet Model Application for Non Premixed Turbulent Combustion written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-11-18 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current Final Report contains results of the study which was performed in Scientific Research Center 'ECOLEN' (Moscow, Russia). The study concerns the development and verification of non-expensive approach for modeling of supersonic turbulent diffusion flames based on flamelet consideration of the chemistry/turbulence interaction (FL approach). Research work included: development of the approach and CFD tests of the flamelet model for supersonic jet flames; development of the simplified procedure for solution of the flamelet equations based on partial equilibrium chemistry assumption; study of the flame ignition/extinction predictions provided by flamelet model. The performed investigation demonstrated that FL approach allowed to describe satisfactory main features of supersonic H 2/air jet flames. Model demonstrated also high capabilities for reduction of the computational expenses in CFD modeling of the supersonic flames taking into account detailed oxidation chemistry. However, some disadvantages and restrictions of the existing version of approach were found in this study. They were: (1) inaccuracy in predictions of the passive scalar statistics by our turbulence model for one of the considered test cases; and (2) applicability of the available version of the flamelet model to flames without large ignition delay distance only. Based on the results of the performed investigation, we formulated and submitted to the National Aeronautics and Space Administration our Project Proposal for the next step research directed toward further improvement of the FL approach. Secundov, A. and Bezgin, L. and Buriko, Yu. and Guskov, O. and Kopchenov, V. and Laskin, I. and Lomkov, K. and Tshepin, S. and Volkov, D. and Zaitsev, S. TURBULENT COMBUSTION; TURBULENT DIFFUSION; DIFFUSION FLAMES; SUPERSONIC JET FLOW; COMPUTATIONAL FLUID DYNAMICS; TURBULENCE MODELS; CHEMICAL REACTIONS; IGNITION; EXTINCTION; GAS MIXTURES; AIR JETS; OXIDATION; DIFFERENTIAL EQUATIONS; MATHEMATICAL MODEL...
Download or read book Transport Phenomena in Fires written by Mohammad Faghri and published by WIT Press. This book was released on 2008 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: Controlled fires are beneficial for the generation of heat and power while uncontrolled fires, like fire incidents and wildfires, are detrimental and can cause enormous material damage and human suffering. This edited book presents the state-of-the-art of modeling and numerical simulation of the important transport phenomena in fires. It describes how computational procedures can be used in analysis and design of fire protection and fire safety. Computational fluid dynamics, turbulence modeling, combustion, soot formation, thermal radiation modeling are demonstrated and applied to pool fires, flame spread, wildfires, fires in buildings and other examples.
Download or read book Study of Finite Rate Chemistry Effects on Turbulent Jet Diffusion Flames and Non homogeneous Autoigntion Using the One Dimensional Turbulence Model written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In current study Numerical simulation of turbulent combustion process is approached using One Dimensional Turbulence (ODT) model. The ODT model is based on the coupling of molecular processes (reaction and diffusion) with turbulent transport in a spatially- and temporally-resolved fashion over a one-dimensional domain. The domain corresponds to a transverse (or radial) direction; while, the transient evolution of the thermo-chemical scalars on the 1D domain represents the spatial evolution downstream of the jet inlet. The linear-eddy approach for modeling molecular mixing in turbulent flow involves stochastic simulation on a 1D domain with sufficient resolution to predict all relevant physical length scales properly. Firstly ODT is carried out to predict the hydrogen and air jet diffusion flame with helium dilution in the fuel. The comparison with existing experimental data was made for the numerical result of ODT simulation of jet diffusion flames in both conditional means and rms of scalars of measurements and computational results. Another application of ODT was made in present work to verify the capability of prediction of autoignition (self-ignition) of one of free shear layer flow -- jet diffusion flow. Different range of pressure and Reynolds number are set to identify the effects of turbulence intensity and mixture properties on the self-ignition chemistry. Autoignition delay time was studied based on these different conditions. At the same time the ability of the prediction of mixture temperature and species mass fraction profile were tested. A principle numerical result is expected and discussed. Conditional pdf and progress variable were used to analyze the computational result of ODT. Analysis was focus on the temperature growth and the mass fraction distribution of intermediate species and product.
Download or read book Experiments and Numerical Simulations of Turbulent Combustion of Diluted Sprays written by Bart Merci and published by Springer Science & Business Media. This book was released on 2014-03-27 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reflects the results of the 2nd and 3rd International Workshops on Turbulent Spray Combustion. The focus is on progress in experiments and numerical simulations for two-phase flows, with emphasis on spray combustion. Knowledge of the dominant phenomena and their interactions allows development of predictive models and their use in combustor and gas turbine design. Experts and young researchers present the state-of-the-art results, report on the latest developments and exchange ideas in the areas of experiments, modelling and simulation of reactive multiphase flows. The first chapter reflects on flame structure, auto-ignition and atomization with reference to well-characterized burners, to be implemented by modellers with relative ease. The second chapter presents an overview of first simulation results on target test cases, developed at the occasion of the 1st International Workshop on Turbulent Spray Combustion. In the third chapter, evaporation rate modelling aspects are covered, while the fourth chapter deals with evaporation effects in the context of flamelet models. In chapter five, LES simulation results are discussed for variable fuel and mass loading. The final chapter discusses PDF modelling of turbulent spray combustion. In short, the contributions in this book are highly valuable for the research community in this field, providing in-depth insight into some of the many aspects of dilute turbulent spray combustion.
Download or read book Filtered Mass Density Function for Subgrid Scale Modeling of Turbulent Diffusion Flames written by and published by . This book was released on 2005 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research was primarily concentrated on the following issues: (1) development of the joint velocity-scalar filtered density function for subgrid scale (SGS) closure of turbulent combustion; and (2) implementation of the scalar filtered density function for large eddy simulation of complex turbulent flames. An extensive systematic study was performed and resulted in significant new findings. With regard to (1), a modelled transport equation was developed and solved for the joint density function. The predicted results via this model were more accurate than other existing SGS models. With regard to (2), the model was employed for prediction of a piloted jet diffusion flame and a bluff-body stabilized flame. The predicted results compared very well with experimental data.
Download or read book A Model Based Closure Approach for Turbulent Combustion Using the One Dimensional Turbulence Model written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new model-based closure approach for turbulent combustion using the One-Dimensional turbulence model (ODT) is developed and validated in context to a turbulent jet diffusion flame. The interaction of turbulence and chemistry provides interesting finite rate chemistry effects including the phenomena of extinction and re-ignition. The ODT model resolves both spatially and temporally all the scales in a turbulent reaction flow problem, thus, combining the accuracy of a DNS like solver with efficiency by reduction in the number of dimensions. The closure approach is based on identifying the mechanisms responsible for the above mentioned effects and parameterizing the ODT results with a minimum set of scalars transported in the coarse grained solvers like the Reynolds-Averaged Navier-Stokes (RANS) or Large Eddy Simulation (LES). Thus, the closure from ODT is based on a "one-way" coupling between the coarse grained solvers and ODT. Two approaches for closure are developed in the present work with respect to a RANS solver; however, they can be easily extended to LES. The first approach relies on ODT to provide the history effects associated with the geometry, which represent the interactions of turbulence and chemistry, by tabulating scalar statistics (first and second moments) on two parameters measuring, the extent of mixing, the radial mean mixture fraction, and the extent of entrainment, the centerline mean mixture fraction. However, based on the above parameterization, the approach is limited to jet diffusion flame geometry. Furthermore, the closure requires a one to one correspondence between the flames simulated in the coarse grained solver and ODT. As a second approach, the results from ODT are parameterized based on general representative scalars; mixture fraction, which specifies the mixedness of the mixture and temperature, which specifies the reactedness of the mixture. The history effects associated with the flow geometry are provided by the RANS solver in t.
Download or read book Mathematical Modelling and Numerical Simulations of Chemically Reacting Turbulent Jets written by Kian Mehravaran and published by . This book was released on 2005 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Advances in Combustion Modelling written by Bernard Larrouturou and published by World Scientific. This book was released on 1991 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume gathers the contributions of six world experts to a course on combustion modelling. Therefore, a pedagogical effort has been made in writing up these texts, which cover state of the art advances in most aspects of combustion science. The book is aimed at students, researches and engineers, as was the course.
Download or read book Numerical Experiments in Homogeneous Turbulence written by Robert Sugden Rogallo and published by . This book was released on 1981 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Research Briefs written by Center for Turbulence Research (U.S.) and published by . This book was released on 2010 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Numerical Simulation for Turbulent Reacting Flows written by Thierry Baritaud and published by Editions TECHNIP. This book was released on 1996 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Description of accurate boundary conditions for the simulation of reactive flows. Parallel direct numerical simulation of turbulent reactive flow. Flame-wall interaction and heat flux modelling in turbulent channel flow. A numerical study of laminar flame wall interaction with detailed chemistry: wall temperature effects. Modeling and simulation of turbulent flame kernel evolution. Experimental and theoretical analysis of flame surface density modelling for premixed turbulent combustion. Gradient and counter-gradient transport in turbulent premixed flames. Direct numerical simulation of turbulent flames with complex chemical kinetics. Effects of curvature and unsteadiness in diffusion flames. Implications for turbulent diffusion combustion. Numerical simulations of autoignition in turbulent mixing flows. Stabilization processes of diffusion flames. References.
