Abo Bibliothek: Guest
TSFP DL Home Archive Vorstand

VARIATIONAL MULTISCALE METHODS FOR LARGE EDDY SIMULATION OF TURBULENT FLOWS: FOURIER ANALYSIS AND APPLICATION TO DIFFUSER FLOW

Volker Gravemeier
Emmy Noether Research Group, Chair for Computational Mechanics, Technical University of Munich Boltzmannstr. 15, D-85748 Garching, Germany

Martin Kronbichler
Division of Scientific Computing, Department of Information Technology, Uppsala University Box 337, SE-751 05 Uppsala, Sweden

Wolfgang A. Wall
Chair for Computational Mechanics, Technical University of Munich Boltzmannstr. 15, D-85748 Garching, Germany

Abstrakt

A variational multiscale large eddy simulation (VMLES) based on an h-type scale separation is derived. Within this method, a standard Smagorinsky model is applied to the smaller of the resolved scales in order to account for the effect of unresolved scales. The larger resolved scales do not contain any modeling term. To separate large and small resolved scales, two grids of different characteristic length are introduced − a fine grid for the resolved scales and a coarser grid for the identification of the large resolved scales. The application of the method to turbulent flow in a diffuser shows the good features of the VMLES already for relatively coarse resolutions. Additionally, a tool based on Fourier analysis is derived, enabling a straightforward classification of scale-separating procedures based on a one-dimensional test equation.