Download or read book A Comparison of Numerical Predictions of Turbulent Diffusion Flame Using Reynolds Averaging and Favre Averaging Approaches written by H. C. Soong and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA 90 1835 AIAA 90 1881 written by and published by . This book was released on 1990 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Numerical Simulations of Premixed Turbulent Flame with Variable Density written by Songwei Zhang and published by . This book was released on 1994 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Combustion Science written by Tsuneo Someya and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-uniform combustion, as encountered in diesel and gas turbine engines, furnaces, and boilers, is responsible for the conversion of fossil fuel to energy and also for the corresponding formation of pollutants. In spite of great research efforts in the past, the mechanism of non-uniform combustion has remained less explored than that of other combustion types, since it consists of many, mostly transient processes which influence each other. In view of this background, a group research project, "Exploration of Combustion Mechanism", was established to explore the mechanism of combustion, especially that of diffusive combustion, and also to find efficient ways to control the combustion process for better utilization of fuel and the reduction of pollutant emission. The group research was started, after preparatory activity of 2 years, in April 1988, for a period of 3 years, as a project with a Grant-in-Aid for Scientific Research of Priority Area subsidized by the Ministry of Education, Science and Culture of Japan. The entire group of 43 members was set up as an organizing committee of 13 members, and five research groups, consisting of 36 members. The research groups were: (1) Steady combustion, (2) Unsteady spray combustion, (3) Control of combustion, (4) Chemistry of combustion, and (5) Effects of fuels. At the beginning of the project it was agreed that we should pursue the mechanism of combustion from a scientific viewpoint, namely, the target of the project was to obtain the fundamentals, or "know why", rather than "know how" of combustion.
Download or read book The Finding Guide to AIAA Meeting Papers written by American Institute of Aeronautics and Astronautics. Technical Information Service and published by . This book was released on 1990 with total page 180 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 1983 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling Detailed Chemistry Effects on Turbulent Diffusion Flames Using a Parallel Solution Adaptive Scheme written by Pradeep Kumar Jha and published by . This book was released on 2011 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: Capturing the effects of detailed-chemistry on turbulent combustion processes is a central challenge faced by the numerical combustion community. However, the inherent complexity and non-linear nature of both turbulence and chemistry require that combustion models rely heavily on engineering approximations to remain computationally tractable. This thesis proposes a computationally efficient algorithm for modelling detailed-chemistry effects in turbulent diffusion flames and numerically predicting the associated flame properties. The cornerstone of this combustion modelling tool is the use of parallel Adaptive Mesh Refinement (AMR) scheme with the recently proposed Flame Prolongation of Intrinsic low-dimensional manifold (FPI) tabulated-chemistry approach for modelling complex chemistry. The effect of turbulence on the mean chemistry is incorporated using a Presumed Conditional Moment (PCM) approach based on a beta-probability density function (PDF). The two-equation k-w turbulence model is used for modelling the effects of the unresolved turbulence on the mean flow field. The finite-rate of methane-air combustion is represented here by using the GRI-Mech 3.0 scheme. This detailed mechanism is used to build the FPI tables. A state of the art numerical scheme based on a parallel block-based solution-adaptive algorithm has been developed to solve the Favre-averaged Navier-Stokes (FANS) and other governing partial-differential equations using a second-order accurate, fully-coupled finite-volume formulation on body-fitted, multi-block, quadrilateral/hexahedral mesh for two-dimensional and three-dimensional flow geometries, respectively. A standard fourth-order Runge-Kutta time-marching scheme is used for time-accurate temporal discretizations. Numerical predictions of three different diffusion flames configurations are considered in the present work: a laminar counter-flow flame; a laminar co-flow diffusion flame; and a Sydney bluff-body turbulent reacting flow. Comparisons are made between the predicted results of the present FPI scheme and Steady Laminar Flamelet Model (SLFM) approach for diffusion flames. The effects of grid resolution on the predicted overall flame solutions are also assessed. Other non-reacting flows have also been considered to further validate other aspects of the numerical scheme. The present schemes predict results which are in good agreement with published experimental results and reduces the computational cost involved in modelling turbulent diffusion flames significantly, both in terms of storage and processing time.
Download or read book Turbulent Shear Flows 3 written by L.J.S. Bradbury and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: In spite of intensive efforts over many decades, the problem of turbulence remains as challenging as ever and the number of papers, books and conferences on this topic con tinues to grow. As experimental techniques and computing power have developed, the breadth of investigations into the structure and development of turbulent flows has in creased to encompass many diverse fields of application in engineering, physics, biolo gy and so on. As a consequence, it is now very difficult for a single research worker to keep in touch with the many developments that are taking place in turbulence. One of the few opportunities for obtaining some overall view of the subject arises from large international symposia on turbulence and, although they have some drawbacks, it is this opportunity that is one of their main merits. The International Symposium on Turbulent Shear Flows has now been held on three occasions and they seem to be established as a major opportunity for papers on a very diverse range of topics to be presented at a single meeting. This volume is a collec tion of papers from the third symposium that was held at the University of California, Davis from 9-11 September 1981. The papers are divided into four sections entitled Wall Flows, Scalar Transport, Recirculating Flows and Fundamentals. This collection represents about a third of the total number of papers presented.
Download or read book Aviation Fuels with Improved Fire Safety written by National Research Council and published by National Academies Press. This book was released on 1997-08-18 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reduction of the fire hazard of fuel is critical to improving survivability in impact-survivable aircraft accidents. Despite current fire prevention and mitigation approaches, fuel flammability can overwhelm post-crash fire scenarios. The Workshop on Aviation Fuels with Improved Fire Safety was held November 19-20, 1996 to review the current state of development, technological needs, and promising technology for the future development of aviation fuels that are most resistant to ignition during a crash. This book contains a summary of workshop discussions and 11 presented papers in the areas of fuel and additive technologies, aircraft fuel system requirements, and the characterization of fuel fires.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Journal of Turbo Jet engines written by and published by . This book was released on 1991 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fossil Energy Update written by and published by . This book was released on 1978 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book JSME International Journal written by and published by . This book was released on 1999 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Review of Numerical Fluid Mechanics and Heat Transfer written by and published by . This book was released on 1987 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy and Combustion Science written by N. A. Chigier and published by Elsevier. This book was released on 2013-10-22 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Energy and Combustion Science is a collection of papers that covers advancement in the field of energy and combustion science. The materials presented in the book are organized thematically into parts. The text first covers the issues, concerns, problems of the contemporary combustion technology. The subsequent parts of the book cover various areas in combustions science, namely, pollution, gas, oil, coal, and engines. Most of the articles in the book are concerned with the byproduct of fuel combustion. The text will be of great use to students, researchers, and practitioners of disciplines that deal with the energy and combustion technology.
Download or read book Modeling of End Gas Autoignition for Knock Prediction in Gasoline Engines written by Andreas Manz and published by Logos Verlag Berlin GmbH. This book was released on 2016-08-18 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Downsizing of modern gasoline engines with direct injection is a key concept for achieving future CO22 emission targets. However, high power densities and optimum efficiency are limited by an uncontrolled autoignition of the unburned air-fuel mixture, the so-called spark knock phenomena. By a combination of three-dimensional Computational Fluid Dynamics (3D-CFD) and experiments incorporating optical diagnostics, this work presents an integral approach for predicting combustion and autoignition in Spark Ignition (SI) engines. The turbulent premixed combustion and flame front propagation in 3D-CFD is modeled with the G-equation combustion model, i.e. a laminar flamelet approach, in combination with the level set method. Autoignition in the unburned gas zone is modeled with the Shell model based on reduced chemical reactions using optimized reaction rate coefficients for different octane numbers (ON) as well as engine relevant pressures, temperatures and EGR rates. The basic functionality and sensitivities of improved sub-models, e.g. laminar flame speed, are proven in simplified test cases followed by adequate engine test cases. It is shown that the G-equation combustion model performs well even on unstructured grids with polyhedral cells and coarse grid resolution. The validation of the knock model with respect to temporal and spatial knock onset is done with fiber optical spark plug measurements and statistical evaluation of individual knocking cycles with a frequency based pressure analysis. The results show a good correlation with the Shell autoignition relevant species in the simulation. The combined model approach with G-equation and Shell autoignition in an active formulation enables a realistic representation of thin flame fronts and hence the thermodynamic conditions prior to knocking by taking into account the ignition chemistry in unburned gas, temperature fluctuations and self-acceleration effects due to pre-reactions. By the modeling approach and simulation methodology presented in this work the overall predictive capability for the virtual development of future knockproof SI engines is improved.
