Numerical FSI investigation based on LES: Flow past a cylinder with a flexible splitter plate involving large deformations (FSI-PfS-2a)

The objective of this paper is to provide a detailed numerical investigation on the fluid-structure interaction (FSI) test case presented in Kalmbach and Breuer (J. of Fluids and Structures, 42, (2013), 369-387). It relies on detailed experimental investigations on the fluid flow and the structure deformation using modern optical measurement techniques such as particle-image velocimetry and laser triangulation sensors. The present numerical study is based on an efficient partitioned FSI coupling scheme especially developed for turbulent flow simulations around light-weight structures using large-eddy simulation. The current FSI configuration is composed of a fixed cylinder with a flexible thin rubber plate and a rear mass inducing a turbulent flow (Re = 30,470). Mainly based on a movement-induced excitation the flexible structure oscillates in the second swiveling mode involving large deformations. Thus, particular attention has been paid to the computational model and the numerical set-up. Special seven-parameters shell elements are applied to precisely model the flexible structure. Structural tests are carried out to approximate the optimal structural parameters. A fine and smooth fluid mesh has been generated in order to correctly predict the wide range of different flow structures presents near and behind the flexible rubber plate. A phase-averaging is applied to the numerical results obtained, so that they can be compared with the phase-averaged experimental data. Both are found to be in close agreement exhibiting a structure deformation in the second swiveling mode with similar frequencies and amplitudes. Finally, a sensitivity study is carried out to show the influence of different physical parameters (e.g. Young's modulus) and modeling aspects (e.g. subgrid-scale model) on the FSI phenomenon. (C) 2014 Elsevier Inc. All rights reserved.