Advances in Les of Complex Flows: Proceedings of the Euromech Colloquium 412, Held in Munich, Germany 4∓6 October 2000

ISBN-13: 9781402004865 / Angielski / Twarda / 2002 / 378 str.

R. Friedrich; W. Rodi; Rainer Friedrich

Opis

This volume contains selected presentations of the "EUROMECH Colloquium 412 on LES of complex transitional and turbulent flows" held at the Munich University of Technology from 4 to 6 October 2000. The articles focus on new developments in the field of large-eddy simulation of complex flows and are related to the topics: modelling and analysis of subgrid scales, numerical issues in LES cartesian grids for complex geometries, curvilinear and non-structured grids for complex geometries. DES and RANS-LES coupling, aircraft wake vortices, combustion and magnetohydrodynamics. Progress has been made not only in understanding and modelling the dynamics of unresolved scales, but also in designing means that prevent the contamination of LES predictions by discretization errors. Progress is reported as well on the use of cartesian and curvilinear coordinates to compute flow in and around complex geometries and in the field of LES with unstructured grids. A chapter is dedicated to the detached-eddy simulation technique and its recent achievements and to the promising technique of coupling RANS and LES solutions in order to push the resolution-based Reynolds number limit of wall-resolving LES to higher values. Complexity due to physical mechanisms links the last two chapters. It is shown that LES constitutes the tool to analyse the physics of aircraft wake vortices during landing and takeoff. Its thorough understanding is a prerequisite for reliable predictions of the distance between consecutive landing airplanes. Subgrid combustion modelling for LES of single and two-phase reacting flows is demonstrated to have the potential to deal with finite-rate kinetics in high Reynolds number flows of full-scale gas turbine engines. Fluctuating magnetic fields are more reliably predicted by LES when tensor-diffusivity rather than gradient-diffusion models are used. An encouraging result in the context of turbulence control by magnetic fields.

Spis treści

Preface. List of Participants. Invited Lectures and Contributions. 1: Modelling and Analysis of Subgrid Scales. Invited lecture: On the physical effects of variable filtering lengths and times in LES; M. Germano. Invited lecture: How can we make LES to fulfill its promise? B.J. Geurts. The approximate deconvolution model for compressible flows: Isotropic turbulence and shock-boundary-layer interaction; S. Stolz, et al. A new mixed model based on the velocity structure function; C. Brun, et al. On the effect of coherent structures on grid/subgrid-scale interactions in plane jets: The transition and far field regions; C.B. da Silva, O. Métais. 2: Numerical Issues in LES. Phase-error reduction in large-eddy simulation using a compact scheme; H.-J. Kaltenbach, D. Driller. DNS and LES of turbulent backward-facing step flow using 2nd and 4th-order discretization; A. Meri, H. Wengle. Parallel multi-domain large-eddy simulation of the flow over a backward-facing step at Re=5100; E. Simons, et al. 3: Cartesian Grids for Complex Geometries. LES of flow around a circular cylinder at a subcritical Reynolds number with Cartesian grids; F. Tremblay, et al. A numerical wind-tunnel experiment; M. Pourquié, et al. 4: Curvilinear and Non-structured Grids for Complex Geometries. Invited lecture: Towards large eddy simulation of complex flows; A. Fureby. Structured and non-structured large eddy simulations of the Ahmed reference model; R.J.A. Howard, et al. Large eddy simulation of fluid flow and heat transfer around a matrix of cubes, using unstructured grids; B. Niceno, K. Hanjalic. Large eddy simulation for flow analysis in a centrifugalpump impeller; R.K. Byskov, et al. 5: DES and RANS-LES Coupling. Invited lecture: Detached-eddy simulation, 1997-2000; P.R. Spalart. Physical and numerical upgrades in the detached-eddy simulation of complex turbulent flows; A. Travin, et al. Detached and large eddy simulation of airfoil flow on semi-structured grids; S. Schmidt, F. Thiele. A multidomain / multiresolution method with application to RANS-LES coupling; P. Quéméré, et al. 6: Aircraft Wake Vortices. Aircraft wake vortex evolution and decay in idealized and real environments: Methodologies, benefits and limitations; F. Holzäpfel, et al. VLES of aircraft wake vortices in a turbulent atmosphere: A study of decay; H. Jeanmart, G.S. Winckelmans. 7: Combustion and Magnetohydrodynamics. Invited lecture: Subgrid combustion modelling for LES of single and two-phase reacting flows; S. Menon. Experimental study of the filtered progress variable approach for LES of premixed combustion; R. Knikker, D. Veynante. Three-dimensional large eddy simulation of decaying magneto-hydro-dynamic turbulence; W.-C. Müller, et al.