An FSI solution technique based on the DSD/SST method and its applications

Abstract

This paper presents a fluid–structure interaction (FSI) solution technique in which the incompressible fluid dynamics involving moving boundaries is solved with the deforming-spatial-domain/stabilized space–time (DSD/SST) method and the structural dynamics is solved with the finite difference (FD) method. The DSD/SST and FD solvers are coupled by an implicit partitioned coupling strategy based on staggered subiterations. Three types of relaxation are applied on the FSI surface velocity and hydrodynamic force. The first one is applied to delay the coupling conditions at the beginning of each simulation; the second one is applied to relax the increment during each subiteration; and the third one is applied to filter high frequency oscillations between each time step. A pitching plate in a uniform flow is calculated to validate the FSI technique. The present results are in good agreement with data predicted by other methods. In addition, two problems are calculated to demonstrate the capability of this solver: an orbital flow over flapping foil propulsion and energy harvesting and a flexible plate in a cavity excited by an external force.