Fluid-structure interaction of engineering geometries using a combined immersed finite element method and finite volume incompressible multiphase solver for high density and high shear flows*

Many industrial fluid flow problems involve the interaction between rigid, heavy objects and one or more fluid phases. In the past few years, the constraint-based immersed boundary method (CIB) has been successfully used to simulate a wide range of fluid-structure interaction (FSI) problems. This method is robust since it can simulate arbitrarily moving bodies on regular Cartesian meshes, making use of adaptive mesh refinement near the fluid-solid interface to adequately resolve boundary layers.

In this work, we extend the CIB formulation and method to allow for a finite element based representation of the structure, enabling fully resolved simulation of industrial geometries. The method is coupled to a novel monolithic incompressible multiphase fluid solver. We show preliminary validation cases for both simple and complex geometries. Novel applications of this method include simulation of self-propelled vehicle aerodynamics and wave energy converter devices, in which the density ratio between the fluid and solid regions are more than three orders of magnitude.