Download or read book Numerical Simulation of Hot Surface Ignition and Combustion of Fuel Sprays written by Danyal Mohaddes Khorassani and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to their high energy density and ease of transportation, liquid fuels continue to be used in a variety of combustion systems, including in aerospace, automotive and industrial applications. Analysis of the underlying physics of multiphase combustion phenomena, particularly as it pertains to ignition, contributes to improved physical understanding and supports greater system reliability and safety. High-fidelity numerical simulations are particularly effective in supporting improved fundamental understanding, but detailed simulations of practical multiphase combustion configurations are highly computationally costly. The study of accidental ignition of liquid fuels and the development of computationally efficient means of performing physically accurate multiphase combustion simulations are therefore important avenues of scientific inquiry. This dissertation considers the problem of the ignition and combustion of a wall-impinging fuel spray using four complementary approaches. First, to analyze the long-term wall heat flux caused by a wall-stagnating spray flame, a steady, one-dimensional, multi-continuum formulation is developed with consideration given to conjugate heat transfer effects. Second, an unsteady, one-dimensional, multi-continuum formulation is developed and a broad parametric study of the hot surface ignition of wall-stagnating fuel sprays is conducted. Third, high-fidelity three-dimensional large-eddy simulations are performed in an Eulerian-Lagrangian formulation using a finite-rate chemistry model. Fourth, the substantial computational cost of the high-fidelity simulations performed motivates the development of a computationally efficient spray combustion modeling framework. This dissertation extends the Pareto-efficient combustion (PEC) modeling framework to spray combustion through a rigorous analysis of the governing equations. The spray-augmented PEC formulation is applied to the high-fidelity simulation of a wall-stagnating spray flame and to the simulation of a realistic gas turbine combustor to demonstrate improved physical fidelity compared to tabulated chemistry, while reducing computational cost compared to monolithic finite-rate chemistry.
Download or read book Droplets and Sprays written by Saptarshi Basu and published by Springer. This book was released on 2017-12-11 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on droplets and sprays relevant to combustion and propulsion applications. The book includes fundamental studies on the heating, evaporation and combustion of individual droplets and basic mechanisms of spray formation. The contents also extend to the latest analytical, numerical and experimental techniques for investigating the behavior of sprays in devices like combustion engines and gas turbines. In addition, the book explores several emerging areas like interactions between sprays and flames and the dynamic characteristics of spray combustion systems on the fundamental side, as well as the development of novel fuel injectors for specific devices on the application side. Given its breadth of coverage, the book will benefit researchers and professionals alike.
Download or read book Numerical Simulation of Combustion Wave Initiation in Mono disperse Fuel Sprays by an Ignition Kernel written by S.-C. Wong and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Numerical Simulation of Spray Combustion Using Bio mass Derived Liquid Fuels written by D. Rochaya and published by . This book was released on 2007 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion of Liquid Fuel Sprays written by Alan Williams and published by Butterworth-Heinemann. This book was released on 2013-10-22 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion of Liquid Fuel Sprays outlines the fundamentals of the combustion of sprays in a unified way which may be applied to any technological application. The book begins with a discussion of the general nature of spray combustion, the sources of liquid fuels used in spray combustion, biomass sources of liquid fuels, and the nature and properties of fuel oils. Subsequent chapters focus on the properties of sprays, the atomization of liquid fuels, and the theoretical modeling of the behavior of a spray flame in a combustion chamber. The nature and control of pollutants from spray combustion, the formation of deposits in oil-fired systems, and the combustion of sprays in furnaces and engines are elucidated as well. The text is intended for students undertaking courses or research in fuel, combustion, and energy studies.
Download or read book Numerical Simulation of Ignition and Transient Combustion in Fuel Vapor Clouds written by Jennifer Wiley 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 Numerical Simulation of Spray Combustion Using Bio mass Derived Liquid Fuels written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this work is to create a robust model for two-phase liquid spray combustion flow using vegetable oils, to investigate the flow structure generated by a swirler array with different fuels, and secondly to assess and optimise the capability of the CFD to predict accurately the results obtained experimentally and eventually enhance CFD model development and simulation. Validation is achieved by comparing the numerical results obtained with CFD with the experimental measurements. The purpose of this research is to increase the scientific understanding of the fundamental mechanisms of the spray combustion process using a carbon neutral fuel such as ethanol and biodiesel. In fact, very few numerical simulations of liquid biomass fuels in gas turbine systems are available in the literature. The flames are simulated using the commercial code FLUENT. The combustion/turbulence interaction is modelled using the laminar flamelet approach with detailed chemistry modelled using the OPPDIFF model from CHEMKIN. While the experiments could be carried out only up to 3 atm, the simulations were further extended to a maximum pressure of 10 atm. The FLUENT results were assessed qualitatively and quantitatively between the experimental measurements and the simulation. The cold flow features have been captured by the present simulations with a good degree of accuracy. Effect of air preheating was investigated for the biodiesel, and sensitivity to droplet size and spray angles variation were analysed. Good agreement was obtained for ethanol except in the fuel lean region due to failure of the FLUENT laminar flamelet model to capture local flame extinction while biodiesel simulation resulted in a significant overprediction of the flame temperature especially in the downstream region and satisfactory results further upstream. The results show the importance of setting proper droplet initial conditions, since it will significantly affect the structure of the flame.
Download or read book Numerical Approaches to Combustion Modeling written by Elaine S. Oran and published by AIAA (American Institute of Aeronautics & Astronautics). This book was released on 1991 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fuel Spray Modeling for Compression Ignition Engine Configurations written by Krishna Latha Ankem and published by . This book was released on 2005 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: The combination of superior fuel economy and durability has made compression ignition direct injection diesel engines popular worldwide. However, these engines can emit large amounts of ozone-forming pollutants and particulates and so are being subjected to increasingly stringent regulations that require continual improvements in the combustion process. Further, improved engine power density is necessary at high load conditions, before the CIDI engine can be considered a contender in the next generation automotive engine technology. Understanding the physics and chemistry involved in diesel combustion, with its transient effects and the inhomogeneity of spray combustion is quite challenging. Great insight into the physics of the problem can be obtained when an in-cylinder computational analysis is used in conjunction with either an experimental program or through published experimental data. The main area to be investigated to obtain good combustion begins by defining the fuel injection process and the mean diameter of the fuel particle, injection pressure, drag coefficient, rate shaping, etc., correctly. This work presents a methodology to perform the task set out in the previous paragraph and uses experimental data obtained from available literature to construct a numerical model. A modified version of a multidimensional computer code called KIVA3V was used for the computations, with improved sub-models for mean droplet diameter, injection pressure and drop distortion and drag. The results achieved show good agreement with the published experimental data. It has been of special importance to model the spray distribution accurately, as the combustion process and the resulting pollutant emission formation is intimately tied to the in-cylinder fuel distribution. The present scheme has achieved excellent results in these aspects and will make an important contribution to the numerical simulation of the combustion process and pollutant emission formation in compression ignition direct injection engines.
Download or read book A Numerical Study of Surface Ignition of a Fuel Spray air Mixture in a Heated Cylindrical Duct written by Yupai L. Tang and published by . This book was released on 1989 with total page 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 Recent Advances in Spray Combustion written by Kenneth K. Kuo and published by AIAA. This book was released on 1996 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Simulation of Liquid fuel Combustor for Control of Combustion written by Kaustav Sengupta and published by . This book was released on 2004 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiple Ignition Combustion and Quenching of Hydrocarbon Fuel Sprays written by S. Aggarwal and published by . This book was released on 1984 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detailed parametric study of the ignition of a monodisperse fuel-air spray in contact with a hot wall was conducted. The theoretical model was one-dimensional unsteady and employed a hybrid Eulerian-Lagrangian numerical scheme. Effects of drop size, chemical kinetics, fuel-air ratios, fuel type and other parameters were examined. The results indicated the statistical character of the spray ignition, the existence of optimum droplet size and optimum fuel-air ratio for the minimum ignition delays. The study was extended to the polydisperse spray. The major conclusion was that the polydisperse results can be correlated with an equivalent monodisperse spray represented by a mean diameter based on the total spray surface area. The study of ignition for sprays flowing over a hot plate as initiated. The formulation and the numerical coding were completed. Currently the code is being employed to predict the ignition delays for the flowing sprays. Preliminary experiments were conducted to investigate the ignition of a single droplet stream along a heated surface. The results show an optimal distance from the surface for the droplet stream. It is speculated that this distance depends on the characteristic evaporation time, diffusion time and convective time inherent to the system. Experiments separating the effects are underway to investigate this interactive process. (Author).
Download or read book Numerical Simulation of the Ignition of Combustible Fuel air Mixtures Flowing in a Tube written by Khan Van Nguyen and published by . This book was released on 1988 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Ignition and Combustion of Fuel Droplets and the Ignition of Premixed Fuels by Hot Cylindrical Surfaces written by Roger H. Rangel and published by . This book was released on 1985 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
