Numerical Investigation of Turbulent Combustion Regimes on Localized Forced Ignition Using Stratified Combustible Mixture

Numerical Investigation of Turbulent Combustion Regimes on Localized Forced Ignition Using Stratified Combustible Mixture PDF Author: Hitha Lokanath Uchil
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Localized forced ignition of turbulent stratified mixtures has been numerically analyzed based on three- dimensional Direct Numerical Simulations (DNS) for different values of Karlovitz number (Ka) corresponding to different turbulent combustion regimes. The initial values of turbulent fluctuations and the integral length scale of turbulence have been modified to bring about the change in Ka. The localized forced ignition is accounted by a source term in the energy transport equation which deposits energy over a time interval. It has been found that combustion takes place predominantly under a premixed mode of combustion following successful ignition. An increase in Ka has shown an increase in Minimum Ignition Energy (MIE) and has been shown to have adverse effects on the burned gas mass. Additionally, a stratified combustion mixture has been found to be a more favorable choice over homogeneous mixtures for a given turbulent ow condition for achieving a higher burning rate.

Numerical Investigation of Turbulent Combustion Regimes on Localized Forced Ignition Using Stratified Combustible Mixture

Numerical Investigation of Turbulent Combustion Regimes on Localized Forced Ignition Using Stratified Combustible Mixture PDF Author: Hitha Lokanath Uchil
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Localized forced ignition of turbulent stratified mixtures has been numerically analyzed based on three- dimensional Direct Numerical Simulations (DNS) for different values of Karlovitz number (Ka) corresponding to different turbulent combustion regimes. The initial values of turbulent fluctuations and the integral length scale of turbulence have been modified to bring about the change in Ka. The localized forced ignition is accounted by a source term in the energy transport equation which deposits energy over a time interval. It has been found that combustion takes place predominantly under a premixed mode of combustion following successful ignition. An increase in Ka has shown an increase in Minimum Ignition Energy (MIE) and has been shown to have adverse effects on the burned gas mass. Additionally, a stratified combustion mixture has been found to be a more favorable choice over homogeneous mixtures for a given turbulent ow condition for achieving a higher burning rate.

Fundamental Investigation of Localised Forced Ignition in Turbulent Homogeneous and Stratified Mixtures

Fundamental Investigation of Localised Forced Ignition in Turbulent Homogeneous and Stratified Mixtures PDF Author: Dipal Patel
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Fundamental Investigation of Localised Forced Ignition in Turbulent Homogeneous and Stratified Mixtures

Fundamental Investigation of Localised Forced Ignition in Turbulent Homogeneous and Stratified Mixtures PDF Author: Dipal Patel
Publisher:
ISBN:
Category :
Languages : en
Pages : 268

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Fundamentals of Premixed Turbulent Combustion

Fundamentals of Premixed Turbulent Combustion PDF Author: Andrei Lipatnikov
Publisher: CRC Press
ISBN: 1466510242
Category : Science
Languages : en
Pages : 551

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Book Description
Lean burning of premixed gases is considered to be a promising combustion technology for future clean and highly efficient gas turbine combustors. Yet researchers face several challenges in dealing with premixed turbulent combustion, from its nonlinear multiscale nature and the impact of local phenomena to the multitude of competing models. Filling a gap in the literature, Fundamentals of Premixed Turbulent Combustion introduces the state of the art of premixed turbulent combustion in an accessible manner for newcomers and experienced researchers alike. To more deeply consider current research issues, the book focuses on the physical mechanisms and phenomenology of premixed flames, with a brief discussion of recent advances in partially premixed turbulent combustion. It begins with a summary of the relevant knowledge needed from disciplines such as thermodynamics, chemical kinetics, molecular transport processes, and fluid dynamics. The book then presents experimental data on the general appearance of premixed turbulent flames and details the physical mechanisms that could affect the flame behavior. It also examines the physical and numerical models for predicting the key features of premixed turbulent combustion. Emphasizing critical analysis, the book compares competing concepts and viewpoints with one another and with the available experimental data, outlining the advantages and disadvantages of each approach. In addition, it discusses recent advances and highlights unresolved issues. Written by a leading expert in the field, this book provides a valuable overview of the physics of premixed turbulent combustion. Combining simplicity and topicality, it helps researchers orient themselves in the contemporary literature and guides them in selecting the best research tools for their work.

Turbulent Combustion Modeling

Turbulent Combustion Modeling PDF Author: Tarek Echekki
Publisher: Springer Science & Business Media
ISBN: 9400704127
Category : Technology & Engineering
Languages : en
Pages : 496

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Book Description
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.

Modeling and Simulation of Turbulent Combustion

Modeling and Simulation of Turbulent Combustion PDF 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.

Numerical Investigation of Turbulent Flame Sheets

Numerical Investigation of Turbulent Flame Sheets PDF Author: S. B. Pope
Publisher:
ISBN:
Category :
Languages : en
Pages : 11

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Book Description
Direct numerical simulations of turbulence are being performed to study fundamental processes of turbulent combustion. In the flame-sheet regime of turbulent premixed combustion an important process is the stretching and bending of the surface by the turbulence. These processes have been comprehensively studied for material surfaces, and a similar study for propagating surfaces is nearing completion. A new closure methodology recently proposed by Kraichnan holds much promise for turbulent reacting flows. An analytic solution to the model equations has been obtained; and it is found that the results are in remarkable agreement with those from our earlier direct numerical simulations. Keywords: Turbulent flames, Premixed flames, Turbulence simulations, Surfaces.

Numerical Simulations of Turbulent Combustion

Numerical Simulations of Turbulent Combustion PDF Author: Andrei Lipatnikov
Publisher:
ISBN: 9783039365463
Category :
Languages : en
Pages : 144

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Numerical Simulations of Turbulent Combustion

Numerical Simulations of Turbulent Combustion PDF Author: Andrei Lipatnikov
Publisher: Mdpi AG
ISBN: 9783039365456
Category : Technology & Engineering
Languages : en
Pages : 142

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Book Description
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.

Fundamental Understanding and Modelling of Turbulent Combustion in Stratified Mixtures Using Direct Numerical Simulations(DNS).

Fundamental Understanding and Modelling of Turbulent Combustion in Stratified Mixtures Using Direct Numerical Simulations(DNS). PDF Author: Sean Malkeson
Publisher:
ISBN:
Category :
Languages : en
Pages :

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