Download or read book Investigation of High resolution Methods in Large eddy Simulation of Subsonic and Supersonic Wall Turbulent Flows written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the motivation, objectives and reasoning behind the undertaken PhD to investigate the capability of compressible Implicit Large Eddy Simulation (ILES) in simulating wall-bounded inhomogeneous flows with particular interest in the near wall region and further presents the progress achieved to date. Investigation includes the assessment of current ILES methods to resolve inhomogeneous turbulence as well as compressible turbulent boundary layers and to improve on those models further. A channel flow is an excellent problem to use to investigate the properties of a SGS model near a wall. The presence of a solid boundary tends to alter the behaviour of the turbulent flow in a number of ways that need to be modeled by the SGS model in order to correctly represent the flow near the wall and most importantly the boundary layer. The presence of the wall inhibits the growth of the small scales, alters the exchange mechanisms between the resolved and unresolved scales and finally gives rise in the SGS near wall region to important Reynolds-stress producing events. A literature survey was carried out to identify other numerical investigations in simulating channel flow as well as data that could be used for validation purposes. The main parameters used to validate the level of resolution in simulating channel flow are identified and a number of tools are developed. The primary parameters extensively used to validate LES simulations of channel flow throughout the literature are mean flow velocity profiles, turbulent kinetic energy, dissipation and shear stress profiles, wall shear stress and friction velocities as well as energy spectra in the spanwise and streamwise homogeneous directions. Compressible viscous ILES of inhomogeneous anisotropic turbulence in an incompressible channel flow at wall normal grid resolutions of 68, 96 and 128 cells are carried out with grid clustering applied to the wall normal direction. Initial results conducted in the compress.
Download or read book Investigation of High resolution Methods in Large eddy Simulation of Subsonic and Supersonic Wall Turbulent Flows written by Ioannis William Kokkinakis and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the motivation, objectives and reasoning behind the undertaken PhDto investigate the capability of compressible Implicit Large Eddy Simulation (ILES) insimulating wall-bounded inhomogeneous flows with particular interest in the near wallregion and further presents the progress achieved to date. Investigation includes the assessmentof current ILES methods to resolve inhomogeneous turbulence as well as compressibleturbulent boundary layers and to improve on those models further. A channel flow is an excellent problem to use to investigate the properties of a SGSmodel near a wall. The presence of a solid boundary tends to alter the behaviour ofthe turbulent flow in a number of ways that need to be modeled by the SGS model inorder to correctly represent the flow near the wall and most importantly the boundarylayer. The presence of the wall inhibits the growth of the small scales, alters the exchangemechanisms between the resolved and unresolved scales and finally gives rise in the SGSnear wall region to important Reynolds-stress producing events. A literature survey was carried out to identify other numerical investigations in simulatingchannel flow as well as data that could be used for validation purposes. The mainparameters used to validate the level of resolution in simulating channel flow are identifiedand a number of tools are developed. The primary parameters extensively used to validateLES simulations of channel flow throughout the literature are mean flow velocity profiles, turbulent kinetic energy, dissipation and shear stress profiles, wall shear stress and frictionvelocities as well as energy spectra in the spanwise and streamwise homogeneousdirections. Compressible viscous ILES of inhomogeneous anisotropic turbulence in an incompressiblechannel flow at wall normal grid resolutions of 68, 96 and 128 cells are carriedout with grid clustering applied to the wall normal direction. Initial results conductedin the compressible regime show that in order to obtain satisfactory results, medium and fine grids are required whereas on coarser grids, some additional numerical method isrequired. Each reconstruction scheme introduces a numerical dissipation characteristic toitself that maybe regarded as a sort of turbulence model. Thus depending on the requireddissipation, a suitable limiter can be chosen. The investigation then moves on to supersonic turbulent flow incorporating shockboundarylayer interaction. Only the slope-limiters that prove to simulate the flow in thefully developed turbulent channel best are favoured and then also utilised in the subsequentcompressible ramp simulations. The capabilities of modelling the shock boundarylayer interaction, mean turbulent profiles and shockwave angle are investigated and comparedagainst those obtained by DNS simulations. It is found that the grid at the inlet ofthe ramp plays a significant role, since it needs to be fine enough to maintain the turbulentin flow at an acceptable level before reaching the shock-boundary layer interaction zone. Further, very high-order numerical reconstructions were found to have difficulties in remainingstable in the high gradient regions of the flow when formulated in conservativeform and therefore solutions were not possible to obtain. Nonetheless, lower order reconstructionmethods run smoothly and the momentum profiles obtained, matched closelythose obtained by DNS.
Download or read book Large Eddy Simulation for Compressible Flows written by Eric Garnier and published by Springer Science & Business Media. This book was released on 2009-08-11 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses both the fundamentals and the practical industrial applications of Large Eddy Simulation (LES) in order to bridge the gap between LES research and the growing need to use it in engineering modeling.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Eddy Simulation for Incompressible Flows written by P. Sagaut and published by Springer Science & Business Media. This book was released on 2006 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt: First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."
Download or read book Large Eddy Simulations for Compressible Turbulent Jet Flows written by Nima Tajallipour and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Eddy Simulation for Incompressible Flows written by Pierre Sagaut and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: First concise textbook on Large-Eddy Simulation, a very important method in scientific computing and engineering From the foreword to the third edition written by Charles Meneveau: "... this meticulously assembled and significantly enlarged description of the many aspects of LES will be a most welcome addition to the bookshelves of scientists and engineers in fluid mechanics, LES practitioners, and students of turbulence in general."
Download or read book Large Eddy Simulation of Supersonic Inlet Flows written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of a shock wave with a turbulent boundary layer is a central problem in supersonic inlet flows. This work uses numerical and analytical techniques to study shock/turbulence interaction in order to identify and explain factors important in shock/boundary layer interaction. Direct numerical simulation of a normal shock wave with an isotropic turbulent field of vorticity and entropy fluctuations showed that negative upstream correlation between the vorticity and entropy fluctuations enhances the turbulence across the shock. Positive upstream correlation has a suppressing effect. A new numerical method providing excellent high wavenumber resolution while reducing the computational cost was developed. A model with no adjustable constants was developed to study the vortex breakdown resulting from the interaction of canard or forbody vortices with the shock waves in a supersonic inlet flow. Very good agreement with both experiment and computation was obtained. A numerical method to compute shock/turbulence interaction using a conservative form of the Large Eddy Simulation (LES) equations has been developed and validated. LES of the interaction of isotropic turbulence with a normal shock was performed and comparisons with direct numerical simulation (DNS) results were favorable. A new Fortran 90 code has been developed for the computation of shock/turbulence interaction. The code is an improved version of codes used previously in shock/turbulence interaction simulations.
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2007 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Eddy Lattice Boltzmann Simulations of Micro Blowing Strategies for Subsonic and Supersonic Drag Control written by and published by . This book was released on 2003 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1991 with total page 1702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1991 with total page 1700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Shear Layers in Supersonic Flow written by Alexander J. Smits and published by Springer Science & Business Media. This book was released on 2006-05-11 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: A good understanding of turbulent compressible flows is essential to the design and operation of high-speed vehicles. Such flows occur, for example, in the external flow over the surfaces of supersonic aircraft, and in the internal flow through the engines. Our ability to predict the aerodynamic lift, drag, propulsion and maneuverability of high-speed vehicles is crucially dependent on our knowledge of turbulent shear layers, and our understanding of their behavior in the presence of shock waves and regions of changing pressure. Turbulent Shear Layers in Supersonic Flow provides a comprehensive introduction to the field, and helps provide a basis for future work in this area. Wherever possible we use the available experimental work, and the results from numerical simulations to illustrate and develop a physical understanding of turbulent compressible flows.
Download or read book Large Eddy Simulations and Direct Numerical Simulations of High Speed Turbulent Reacting Flows written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-10-22 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective is to extend the boundaries within which large eddy simulations (LES) and direct numerical simulations (DNS) can be applied in computational analyses of high speed reacting flows. In the efforts related to LES, we were concerned with developing reliable subgrid closures for modeling of the fluctuation correlations of scalar quantities in reacting turbulent flows. In the work on DNS, we focused our attention to further investigation of the effects of exothermicity in compressible turbulent flows. In our previous work, in the first year of this research, we have considered only 'simple' flows. Currently, we are in the process of extending our analyses for the purpose of modeling more practical flows of current interest at LaRC. A summary of our accomplishments during the third six months of the research is presented. Givi, P. and Madnia, C. K. and Steinberger, C. J. and Frankel, S. H. and Vidoni, T. J. Unspecified Center NAG1-1122...
Download or read book High Performance Computing in Science and Engineering 20 written by Wolfgang E. Nagel and published by Springer Nature. This book was released on 2022-01-01 with total page 577 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the state-of-the-art in supercomputer simulation. It includes the latest findings from leading researchers using systems from the High Performance Computing Center Stuttgart (HLRS) in 2020. The reports cover all fields of computational science and engineering ranging from CFD to computational physics and from chemistry to computer science with a special emphasis on industrially relevant applications. Presenting findings of one of Europe’s leading systems, this volume covers a wide variety of applications that deliver a high level of sustained performance. The book covers the main methods in high-performance computing. Its outstanding results in achieving the best performance for production codes are of particular interest for both scientists and engineers. The book comes with a wealth of color illustrations and tables of results.
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
