Fluid–structure interaction for an elastic structure interacting with free surface in a rolling tank

Abstract

A fully coupled approach to large deformation fluid–structure interaction (FSI) using a nonlinear finite element (FEM) solver and a URANS/DES overset solver is presented. Since the relationship between strains and displacement cannot be treated as linear at large deformation problems, a nonlinear FEM treating geometric nonlinearity is applied instead of a linear modal analysis for a structure solver. For large deformation the reinitialization of the overset hole-cutting, which is carried out by default only at the beginning of the computation, is performed automatically at each time step. The approach uses the gluing method to transfer the forces and displacements on non-matching grids for fluid and structure domains. A linear FEM solver is applied to deform the outer boundary of the boundary layer grids which wrap around the deformable geometries. The deformation of interior points in the boundary layer grid is obtained using linear interpolation. Three cases of rolling tanks partially filled with fluid with an elastic bar clamped to bottom or top are simulated and compared with experiments and other numerical simulation results. The simulation results of the presented method show good agreement with the experiments for bar deformation and free surface elevation.