CFD Prediction of Coupled Radiation Heat Transfer and Soot Production in Turbulent Flames


Book Description

The mechanisms governing the formation and destruction of soot in turbulent combustion are intimately coupled to thermal radiation due to the strong dependence of sooting processes and radiative loss on temperature. Detailed computational fluid dynamics (CFD) predictions of the radiative and soot output from turbulent non-premixed flames are normally performed by parabolic algorithms. However, the modelling of combustion systems, such as furnaces and unwanted enclosure fires, often require a fully elliptic description of the flow field and its related physical phenomena. Thus, this thesis investigates the intimate coupling between radiative energy exchange and the mechanisms governing soot formation and destruction within a three-dimensional, general curvilinear CFD code. Thermal radiation is modelled by the discrete transfer radiation model (DTRM). Special emphasis is given to approximate solutions to the radiative transfer equation encompassing various models for the radiative properties of gases and soot. A new algorithm is presented, entitled the differential total absorptivity (DTA) solution, which, unlike alternative solutions, incorporates the source temperature dependence of absorption. Additionally, a weighted sum of gray gases (WSGG) solution is described which includes the treatment of gray boundaries. Whilst the DTA solution is particularly recommended for systems comprising large temperature differences, the WSGG solution is deemed most appropriate for numerical simulation of lower temperature diffusion flames, due to its significant time advantage. The coupling between radiative loss and soot concentration is investigated via a multiple laminar flamelet concept applied within the CFD simulation of confined turbulent diffusion flames burning methane in air at 1 and 3 atm. Flamelet families are employed relating individual sooting mechanisms to the level of radiative loss, which is evaluated by the DTRM formulated for emitting-absorbing mixtures of soot,







Radiative Heat Transfer


Book Description

The most comprehensive and detailed treatment of thermal radiation heat transfer available for graduate students, as well as senior undergraduate students, practicing engineers and physicists is enhanced by an excellent writing style with nice historical highlights and a clear and consistent notation throughout. Modest presents radiative heat transfer and its interactions with other modes of heat transfer in a coherent and integrated manner emphasizing the fundamentals. Numerous worked examples, a large number of problems, many based on real world situations, and an up-to-date bibliography make the book especially suitable for independent study. Most complete text in the field of radiative heat transfer Many worked examples and end-of-chapter problems Large number of computer codes (in Fortran and C++), ranging from basic problem solving aids to sophisticated research tools Covers experimental methods




Transport Phenomena in Fires


Book Description

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.




Industrial Combustion Pollution and Control


Book Description

This reference overflows with an abundance of experimental techniques, simulation strategies, and practical applications useful in the control of pollutants generated by combustion processes in the metals, minerals, chemical, petrochemical, waste, incineration, paper, glass, and foods industries. The book assists engineers as they attempt to meet e




Computational Fluid Dynamics in Industrial Combustion


Book Description

Although many books have been written on computational fluid dynamics (CFD) and many written on combustion, most contain very limited coverage of the combination of CFD and industrial combustion. Furthermore, most of these books are written at an advanced academic level, emphasize theory over practice, and provide little help to engineers who need to use CFD for combustion modeling. Computational Fluid Dynamics in Industrial Combustion fills this gap in the literature. Focusing on topics of interest to the practicing engineer, it codifies the many relevant books, papers, and reports written on this combined subject into a single, coherent reference. It looks at each topic from a somewhat narrow perspective to see how that topic affects modeling in industrial combustion. The editor and his team of expert authors address these topics within three main sections: Modeling Techniques-The basics of CFD modeling in combustion Industrial Applications-Specific applications of CFD in the steel, aluminum, glass, gas turbine, and petrochemical industries Advanced Techniques-Subjects rarely addressed in other texts, including design optimization, simulation, and visualization Rapid increases in computing power and significant advances in commercial CFD codes have led to a tremendous increase in the application of CFD to industrial combustion. Thorough and clearly representing the techniques and issues confronted in industry, Computational Fluid Dynamics in Industrial Combustion will help bring you quickly up to date on current methods and gain the ability to set up and solve the various types of problems you will encounter.




Heat Transfer in Industrial Combustion


Book Description

Industry relies heavily on the combustion process. The already high demand for energy, primarily from combustion, is expected to continue to rapidly increase. Yet, the information is scattered and incomplete, with very little attention paid to the overall combustion system. Designed for practicing engineers, Heat Transfer in Industrial Combustion e




Parallel Computational Fluid Dynamics '97


Book Description

Computational Fluid Dynamics (CFD) is a discipline that has always been in the vanguard of the exploitation of emerging and developing technologies. Advances in both algorithms and computers have rapidly been absorbed by the CFD community in its quest for more accurate simulations and reductions in the time to solution. Within this context, parallel computing has played an increasingly important role. Moreover, the uptake of parallel computing has brought the CFD community into ever-closer contact with hardware vendors and computer scientists. The multidisciplinary subject of parallel CFD and its rapidly evolving nature, in terms of hardware and software, requires a regular international meeting of this nature to keep abreast of the most recent developments. Parallel CFD '97 is part of an annual conference series dedicated to the discussion of recent developments and applications of parallel computing in the field of CFD and related disciplines. This was the 9th in the series, and since the inaugural conference in 1989, many new developments and technologies have emerged. The intervening years have also proved to be extremely volatile for many hardware vendors and a number of companies appeared and then disappeared. However, the belief that parallel computing is the only way forward has remained undiminished. Moreover, the increasing reliability and acceptance of parallel computers has seen many commercial companies now offering parallel versions of their codes, many developed within the EC funded EUROPORT activity, but generally for more modest numbers of processors. It is clear that industry has not moved to large scale parallel systems but it has shown a keen interest in more modest parallel systems recognising that parallel computing will play an important role in the future. This book forms the proceedings of the CFD '97 conference, which was organised by the the Computational Engineering Group at Daresbury Laboratory and held in Manchester, England, on May 19-21 1997. The sessions involved papers on many diverse subjects including turbulence, reactive flows, adaptive schemes, unsteady flows, unstructured mesh applications, industrial applications, developments in software tools and environments, climate modelling, parallel algorithms, evaluation of computer architectures and a special session devoted to parallel CFD at the AEREA research centres. This year's conference, like its predecessors, saw a continued improvement in both the quantity and quality of contributed papers. Since the conference series began many significant milestones have been acheived. For example in 1994, Massively Parallel Processing (MPP) became a reality with the advent of Cray T3D. This, of course, has brought with it the new challenge of scalability for both algorithms and architectures. In the 12 months since the 1996 conference, two more major milestones were achieved: microprocessors with a peak performance of a Gflop/s became available and the world's first Tflop/s calculation was performed. In the 1991 proceedings, the editors indicated that a Tflop/s computer was likely to be available in the latter half of this decade. On December 4th 1996, Intel achieved this breakthrough on the Linpack benchmark using 7,264 (200MHz) Pentium Pro microprocessors as part of the ASCI Red project. With the developments in MPP, the rapid rise of SMP architectures and advances in PC technology, the future for parallel CFD looks both promising and challenging.




Microgravity Combustion


Book Description

This book provides an introduction to understanding combustion, the burning of a substance that produces heat and often light, in microgravity environments-i.e., environments with very low gravity such as outer space. Readers are presented with a compilation of worldwide findings from fifteen years of research and experimental tests in various low-gravity environments, including drop towers, aircraft, and space.Microgravity Combustion is unique in that no other book reviews low- gravity combustion research in such a comprehensive manner. It provides an excellent introduction for those researching in the fields of combustion, aerospace, and fluid and thermal sciences. * An introduction to the progress made in understanding combustion in a microgravity environment* Experimental, theoretical and computational findings of current combustion research* Tutorial concepts, such as scaling analysis* Worldwide microgravity research findings




Genmix


Book Description

Genmix: A General Computer Program for Two-dimensional Parabolic Phenomena explains a computer program called GENMIX. The main intention of the program is to be used as a tool of instructions. The name of the program is a mixture of two considerations: its generality and its concern for mixing processes. The book aims to help the potential user to understand the physical and mathematical basis of the topic computer program. It is also the aim of the book to make the program applicable to practical problems. The book is arranged in such a way as to parallel a course of lectures and associated computer-workshop sessions wherein the student is allowed to do some elementary computations as soon as he has gained some knowledge of the method. The book contains the mathematical, physical, and computer-coding aspects of the program. Concepts such as the boundary layer, two-dimensional, and steady- flow are defined and discussed in depth. The text will be a useful tool for computer instructors and students.