A Unified Finite Element Method for Fluid-Structure Interaction

Abstract: In this article, we present a new unified finite element method (UFEM) for simulation of general Fluid-Structure interaction (FSI) which has the same generality and robustness as monolithic methods but is significantly more computationally efficient and easier to implement. Our proposed approach has similarities with classical immersed finite element methods (IFEMs), by approximating a single velocity and pressure field in the entire domain (i.e. occupied by fluid and solid) on a single mesh, but differs by treating the corrections due to the solid deformation on the left-hand side of the modified fluid flow equations (i.e. implicitly). The method is described in detail, followed by the presentation of multiple computational examples in order to validate it across a wide range of fluid and solid parameters and interactions.