Author: Kshitij V. Deshmukh Publisher: ISBN: Category : Languages : en Pages :
Book Description
Turbulent combustion is encountered in many industrial applications such as combustors, nozzles, turbines, engines and furnaces. The increasing concern for pollutant emissions to the environment has led to a wide interest in studying the process in detail using numerical simulation with an aim to develop predictive models that would minimize expensive experiments. Three main approaches in this direction are direct numerical simulation (DNS), large eddy simulation (LES) and Reynolds average simulation (RAS). Moreover, the presence of high temperatures in turbulent combustion results in substantial heat transfer by radiation. Most work until today has either simplified or neglected radiation. This leads to neglect of turbulence?radiation interactions (TRI). In this work, DNS is coupled with a photon Monte Carlo method to solve the radiative transfer equation (RTE) to isolate and quantify TRI. A canonical statistically one-dimensional turbulent premixed combustion system is studied. The inflow boundary condition is improved to introduce turbulence and to help simulate a quasi-stationary flow. Both emission TRI and absorption TRI were found to be significant. A statistical analysis showed that using a moving average over time of the radiative source term reduces statistical noise and saves valuable computational resources without affecting the overall solution. For the first time, a third-order spherical harmonics method, P3 approximation is coupled with DNS to replace the photon Monte Carlo method. A canonical turbulent premixed combustion system is simulated and TRI are studied at large-to-small optical thicknesses. Emission TRI was found to be significant at all optical thickness, while absorption TRI was important at large and intermediate optical thickness and negligible at the optically thin limit. The implementation of the P3 approximation is seen as a viable alternative to the costly photon Monte Carlo method. Elliptic equations are typically solved in RAS-based and LES-based modeling and the P3 approximation consists of six elliptical partial differential equations (PDEs). It is hoped that the demonstration of use of the P3 approximation will generate interest for it to be included in future LES and RAS approaches and developments. A low-order model for LES using a?-PDF approach is also developed for a canonical statistically one-dimensional turbulent nonpremixed system. The mixture fraction and its variance are inputs to the model to obtain a PDF of mixture fraction. With the knowledge of the PDF of mixture fraction, the quantities that are functions of mixture fraction are convoluted with the mixture fraction PDF to obtain the chemical source term and the radiative emission terms. The mean profiles are predicted correctly but the nonlinear terms of radiative emission are not captured accurately, as the?-PDF cannot provide information for the higher-order terms. Still, as a one-equation model to be used as a first pass for LES simulation, this model has its advantages in that it is easy to implement and uses negligible additional computational resources over what is required for LES without any models.
Author: Michael F. Modest Publisher: Springer ISBN: 3319272918 Category : Science Languages : en Pages : 167
Book Description
This introduction reviews why combustion and radiation are important, as well as the technical challenges posed by radiation. Emphasis is on interactions among turbulence, chemistry and radiation (turbulence-chemistry-radiation interactions – TCRI) in Reynolds-averaged and large-eddy simulations. Subsequent chapters cover: chemically reacting turbulent flows; radiation properties, Reynolds transport equation (RTE) solution methods, and TCRI; radiation effects in laminar flames; TCRI in turbulent flames; and high-pressure combustion systems. This Brief presents integrated approach that includes radiation at the outset, rather than as an afterthought. It stands as the most recent developments in physical modeling, numerical algorithms, and applications collected in one monograph.
Author: Michael F. Modest Publisher: Academic Press ISBN: 032398407X Category : Science Languages : en Pages : 1018
Book Description
Radiative Heat Transfer, Fourth Edition is a fully updated, revised and practical reference on the basic physics and computational tools scientists and researchers use to solve problems in the broad field of radiative heat transfer. This book is acknowledged as the core reference in the field, providing models, methodologies and calculations essential to solving research problems. It is applicable to a variety of industries, including nuclear, solar and combustion energy, aerospace, chemical and materials processing, as well as environmental, biomedical and nanotechnology fields. Contemporary examples and problems surrounding sustainable energy, materials and process engineering are an essential addition to this edition. Includes end-of-chapter problems and a solutions manual, providing a structured and coherent reference Presents many worked examples which have been brought fully up-to-date to reflect the latest research Details many computer codes, ranging from basic problem solving aids to sophisticated research tools
Author: Nedunchezhian Swaminathan Publisher: Cambridge University Press ISBN: 1139498584 Category : Technology & Engineering Languages : en Pages : 447
Book Description
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.
Author: Andreas Kling Publisher: Springer Science & Business Media ISBN: 3642182119 Category : Science Languages : en Pages : 1200
Book Description
This book focuses on the state of the art of Monte Carlo methods in radiation physics and particle transport simulation and applications. Special attention is paid to algorithm development for modeling, and the analysis of experiments and measurements in a variety of fields.
Author: Richard L. Morin Publisher: CRC Press ISBN: 1000005933 Category : Medical Languages : en Pages : 244
Book Description
First Published in 1988, this book offers a full exploration into the applications of the Monte Carlo Simulation. Carefully compiled and filled with a vast repertoire of notes, diagrams, and references this book serves as a useful reference for Students of Radiology, and other practitioners in their respective fields.
Author: Tarek Echekki Publisher: Springer Science & Business Media ISBN: 9400704127 Category : Technology & Engineering Languages : en Pages : 496
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.
Author: Kshitij V. Deshmukh
Author: Michael F. Modest
Author: Michael F. Modest
Author: 
Author: Nedunchezhian Swaminathan
Author: Andreas Kling
Author: 
Author: Richard L. Morin
Author: Tarek Echekki
Author: Murat Yaldizli