Direct and Large-Eddy Simulation VII / ERCOFTAC Series Bd.13 (PDF)

"LES Meets FSI – Important Numerical and Modeling Aspects (p. 245-246)

M. Breuer1,2 and M. Münsch2

1 Dept. of Fluid Mechanics, Institute of Mechanics, Helmut-Schmidt-University Hamburg, Holstenhofweg 85, D-22043 Hamburg, Germany, breuer@hsu-hh.de 2 Institute of Fluid Mechanics, University of Erlangen-N¨urnberg, Cauerstr. 4, D-1058 Erlangen, Germany, mmuensch@lstm.uni-erlangen.de

Abstract The paper is concerned with two main aspects, which should be considered when large–eddy simulation (LES) is married to ?uid–structure interaction (FSI). First, the in?uence of moving grids leading to temporally varying ?lter widths and thus additional commutation errors on the quality of the predicted results is thoroughly investigated. Second, a new partitioned coupling method based on the predictor–corrector scheme often used for LES is evaluated. A strongly coupled but nevertheless still explicit time–stepping algorithm results, which is very e?cient in the LES–FSI context. This new scheme is evaluated in detail based simulations around elastically supported cylindrical structures and a swiveling ?at plate.

1 Introduction

Fluid–structure interaction (FSI) plays a dominant role in many technical applications such as suspension bridges, o?-shore platforms or even vocal folds. Therefore, a strong need for appropriate numerical simulation tools exists for such coupled problems. In previous studies, FSI applications in the regime of laminar ?ows as well as turbulent ?ows using the RANS approach [5, 6] were numerically investigated. For that purpose, a partitioned fully implicit scheme was applied which coupled a three-dimensional ?nite-volume based multi-block ?ow solver for incompressible ?uids with a ?nite-element code for the structural problem.

This coupling scheme works e?ciently for large time step sizes typically used for implicit time-stepping schemes