Numerical Analysis of Turbulent Reacting Flows in Complex Combustion Systems PDF Download

Author: Murat Yaldizli
Publisher:
ISBN:
Category : Combustion engineering
Languages : en
Pages : 442

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Author: Thierry Baritaud
Publisher: Editions TECHNIP
ISBN: 9782710806981
Category : Science
Languages : en
Pages : 328

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Book Description
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.

Author: R. S. Cant
Publisher: Imperial College Press
ISBN: 1860947786
Category : Science
Languages : en
Pages : 192

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Provides physical intuition and key entries to the body of literature. This book includes historical perspective of the theories.

Author: R. W. Bilger
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 272

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Author: Èric Godayol Capdevila
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Combustion is a complex phenomenon of interest that combines chemical reactions and turbulent flows. Resolution of both problems is a difficult task. On the one hand, chemical reactions introduce a large amount of species with different properties and small temporal scales due to chemical kinetics. On the other hand, turbulent flows imply a large span of spatial scales. Different models are commonly applied to reduce these requirements. Chemical reactions can be modeled with reduced chemical mechanisms. These have less species and reactions than complex ones, but are able to describe the combustion. Turbulence is modeled by means of Large Eddy Simulation (LES), which filters the Navier-Stokes equations spatially. Thus, the small scales of the flow are filtered out. These ones are modeled through a turbulent viscosity. The present study focuses on the theoretical basis required to model combustion phenomena. First, the algorithm used to solve variable density flows is presented. It uses the low-Mach equations, which are discretized in terms of the convective-diffusive equation. Its resolution is achieved by applying an algorithm based on a projection method, using a predictor-corrector step. Then the algorithm used to solve chemical kinetics is detailed. In this case, the Arrhenius law is used for laminar flames and a two equations model for turbulent flows. The latter introduces an eddy dissipation model besides the Arrhenius law to include the effect of the filtered spatial scales in LES simulations. The study concludes with an introduction to LES. The spatial filter introduces some additional terms in the governing equations. These ones are modeled through a turbulent viscosity. Different models to evaluate the turbulent viscosity can be found in the literature. In the present study the Smagorinsky model is used. Different tests are carried out to verify the results. The lid driven cavity and the heated cavity tests show that accurate results are obtained for incompressible and variable density non-reacting flows. A laminar methane/air flame test is used to verify the laminar chemical algorithm. Additionally, the influence of chemical mechanism on the flame behavior is shown. Finally, a three dimensional propane burner is simulated to study the turbulent combustion phenomena and verify the interaction between turbulent combustion chemical algorithm and LES. An additional test is used to assess the speedup of the parallelization implemented and also to check its performance.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309046483
Category : Technology & Engineering
Languages : en
Pages : 145

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Book Description
Computational mechanics is a scientific discipline that marries physics, computers, and mathematics to emulate natural physical phenomena. It is a technology that allows scientists to study and predict the performance of various productsâ€"important for research and development in the industrialized world. This book describes current trends and future research directions in computational mechanics in areas where gaps exist in current knowledge and where major advances are crucial to continued technological developments in the United States.

Author: Santanu De
Publisher: Springer
ISBN: 9811074100
Category : Science
Languages : en
Pages : 663

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Book Description
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.

Author: R. Borghi
Publisher: Springer Science & Business Media
ISBN: 146139631X
Category : Science
Languages : en
Pages : 958

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Book Description
Turbulent reactive flows are of common occurrance in combustion engineering, chemical reactor technology and various types of engines producing power and thrust utilizing chemical and nuclear fuels. Pollutant formation and dispersion in the atmospheric environment and in rivers, lakes and ocean also involve interactions between turbulence, chemical reactivity and heat and mass transfer processes. Considerable advances have occurred over the past twenty years in the understanding, analysis, measurement, prediction and control of turbulent reactive flows. Two main contributors to such advances are improvements in instrumentation and spectacular growth in computation: hardware, sciences and skills and data processing software, each leading to developments in others. Turbulence presents several features that are situation-specific. Both for that reason and a number of others, it is yet difficult to visualize a so-called solution of the turbulence problem or even a generalized approach to the problem. It appears that recognition of patterns and structures in turbulent flow and their study based on considerations of stability, interactions, chaos and fractal character may be opening up an avenue of research that may be leading to a generalized approach to classification and analysis and, possibly, prediction of specific processes in the flowfield. Predictions for engineering use, on the other hand, can be foreseen for sometime to come to depend upon modeling of selected features of turbulence at various levels of sophistication dictated by perceived need and available capability.

Author:
Publisher: Elsevier
ISBN: 0444640886
Category : Technology & Engineering
Languages : en
Pages : 1034

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Book Description
Mathematical Modelling of Gas-Phase Complex Reaction Systems: Pyrolysis and Combustion, Volume 45, gives an overview of the different steps involved in the development and application of detailed kinetic mechanisms, mainly relating to pyrolysis and combustion processes. The book is divided into two parts that cover the chemistry and kinetic models and then the numerical and statistical methods. It offers a comprehensive coverage of the theory and tools needed, along with the steps necessary for practical and industrial applications. Details thermochemical properties and "ab initio" calculations of elementary reaction rates Details kinetic mechanisms of pyrolysis and combustion processes Explains experimental data for improving reaction models and for kinetic mechanisms assessment Describes surrogate fuels and molecular reconstruction of hydrocarbon liquid mixtures Describes pollutant formation in combustion systems Solves and validates the kinetic mechanisms using numerical and statistical methods Outlines optimal design of industrial burners and optimization and dynamic control of pyrolysis furnaces Outlines large eddy simulation of turbulent reacting flows

Author: Nedunchezhian Swaminathan
Publisher: Springer Nature
ISBN: 303116248X
Category : Technology & Engineering
Languages : en
Pages : 353

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Book Description
This open access book introduces and explains machine learning (ML) algorithms and techniques developed for statistical inferences on a complex process or system and their applications to simulations of chemically reacting turbulent flows. These two fields, ML and turbulent combustion, have large body of work and knowledge on their own, and this book brings them together and explain the complexities and challenges involved in applying ML techniques to simulate and study reacting flows. This is important as to the world’s total primary energy supply (TPES), since more than 90% of this supply is through combustion technologies and the non-negligible effects of combustion on environment. Although alternative technologies based on renewable energies are coming up, their shares for the TPES is are less than 5% currently and one needs a complete paradigm shift to replace combustion sources. Whether this is practical or not is entirely a different question, and an answer to this question depends on the respondent. However, a pragmatic analysis suggests that the combustion share to TPES is likely to be more than 70% even by 2070. Hence, it will be prudent to take advantage of ML techniques to improve combustion sciences and technologies so that efficient and “greener” combustion systems that are friendlier to the environment can be designed. The book covers the current state of the art in these two topics and outlines the challenges involved, merits and drawbacks of using ML for turbulent combustion simulations including avenues which can be explored to overcome the challenges. The required mathematical equations and backgrounds are discussed with ample references for readers to find further detail if they wish. This book is unique since there is not any book with similar coverage of topics, ranging from big data analysis and machine learning algorithm to their applications for combustion science and system design for energy generation.