Download or read book Investigation of an Inhomogeneous Mixing Model for Conditional Moment Closure Applied to Autoignition written by Adrian Milford and published by . This book was released on 2010 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: Autoignition of high pressure methane jets at engine relveant conditions within a shock tube is investigated using Conditional Moment Closure (CMC). The impact of two commonly used approximations applied in previous work is examined, the assumption of homogeneous turbulence in the closure of the micro-mixing term and the assumption of negligible radial variation of terms within the CMC equations. In the present work two formulations of an inhomogeneous mixing model are implemented, both utilizing the [beta] -PDF, but differing in the respective conditional velocity closure that is applied. The common linear model for conditional velocity is considered, in addition to the gradient diffusion model. The validity of cross-stream averaging the CMC equations is examined by comparing results from two-dimensional (axial and radial) solution of the CMC equations with cross-stream averaged results. The CMC equations are presented and all terms requiring closure are discussed. So- lution of the CMC equations is decoupled from the flow field solution using the frozen mixing assumption. Detailed chemical kinetics are implemented. The CMC equations are discretized using finite differences and solved using a fractional step method. To maintain consistency between the mixing model and the mixture fraction variance equation, the scalar dissipation rate from both implementations of the inhomogeneous model are scaled. The autoignition results for five air temperatures are compared with results obtained using homogeneous mixing models and experimental data. The gradient diffusion conditional velocity model is shown to produce diverging be- haviour in low probability regions. The corresponding profiles of conditional scalar dis- sipation rate are negatively impacted with the use of the gradient model, as unphysical behaviour at lean mixtures within the core of the fuel jet is observed. The predictions of ignition delay and location from the Inhomogeneous-Linear model are very close to the homogeneous mixing model results. The Inhomogeneous-Gradient model yields longer ignition delays and ignition locations further downstream. This is influenced by the higher scalar dissipation rates at lean mixtures resulting from the divergent behaviour of the gradient conditional velocity model. The ignition delays obtained by solving the CMC equations in two dimensions are in excellent agreement with the cross-stream averaged values, but the ignition locations are predicted closer to the injector.
Download or read book Issues in Energy Conversion Transmission and Systems 2011 Edition written by and published by ScholarlyEditions. This book was released on 2012-01-09 with total page 863 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Energy Conversion, Transmission, and Systems: 2011 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Energy Conversion, Transmission, and Systems. The editors have built Issues in Energy Conversion, Transmission, and Systems: 2011 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Energy Conversion, Transmission, and Systems in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Energy Conversion, Transmission, and Systems: 2011 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
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 Ignition Delay of Non Premixed Methane Air Mixtures Using Conditional Moment Closure CMC written by Ahmad El Sayed and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Conditional Moment Closure for Autoignition in Turbulent Flows written by Giorgio De Paola and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1996 with total page 724 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.
Download or read book Proceedings of the ASME Fluids Engineering Division Summer Conference 2006 written by American Society of Mechanical Engineers. Fluids Engineering Division and published by . This book was released on 2006 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the ASME Joint U S European Fluids Engineering Conference written by and published by . This book was released on 2006 with total page 950 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion for Power Generation and Transportation written by Avinash Kumar Agarwal and published by Springer. This book was released on 2017-01-20 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research monograph presents both fundamental science and applied innovations on several key and emerging technologies involving fossil and alternate fuel utilization in power and transport sectors from renowned experts in the field. Some of the topics covered include: autoignition in laminar and turbulent nonpremixed flames; Langevin simulation of turbulent combustion; lean blowout (LBO) prediction through symbolic time series analysis; lasers and optical diagnostics for next generation IC engine development; exergy destruction study on small DI diesel engine; and gasoline direct injection. The book includes a chapter on carbon sequestration and optimization of enhanced oil and gas recovery. The contents of this book will be useful to researchers and professionals working on all aspects on combustion.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 988 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 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 Direct and Large Eddy Simulation written by Bernard J. Geurts and published by de Gruyter. This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This authoritative book presents an overview of the mathematics behind the simulation of turbulent flows and discusses in detail the phenomenology of turbulence in fluid dynamics, direct and large-eddy simulations, subgrid modeling, and also covers
Download or read book Turbulent Flows written by Stephen B. Pope and published by Cambridge University Press. This book was released on 2000-08-10 with total page 810 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a graduate text on turbulent flows, an important topic in fluid dynamics. It is up-to-date, comprehensive, designed for teaching, and is based on a course taught by the author at Cornell University for a number of years. The book consists of two parts followed by a number of appendices. Part I provides a general introduction to turbulent flows, how they behave, how they can be described quantitatively, and the fundamental physical processes involved. Part II is concerned with different approaches for modelling or simulating turbulent flows. The necessary mathematical techniques are presented in the appendices. This book is primarily intended as a graduate level text in turbulent flows for engineering students, but it may also be valuable to students in applied mathematics, physics, oceanography and atmospheric sciences, as well as researchers and practising engineers.
Download or read book Radiative Heat Transfer in Turbulent Combustion Systems written by Michael F. Modest and published by Springer. This book was released on 2016-01-06 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
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.
