An Energy stable Monolithic Eulerian Fluid-Structure Numerical Scheme *

TL;DR

This paper presents a monolithic Eulerian numerical scheme for fluid-structure interactions that is energy stable, applicable to both compressible and incompressible fluids, with analysis, discretization, and initial testing.

Contribution

It introduces an energy stable monolithic Eulerian scheme for FSI that unifies fluid and solid mechanics in a single framework, with stability analysis and practical implementation insights.

Findings

The scheme is energy stable based on an energy estimate.

Implementation issues are discussed with initial numerical tests.

Applicable to both compressible and incompressible fluids.

Abstract

The conservation laws of continuum mechanic written in an Eulerian frame make no difference between fluids and solids except in the expression of the stress tensors, usually with Newton's hypothesis for the fluids and Helmholtz potentials of energy for hyperelastic solids. By taking the velocities as unknown , monolithic methods for fluid structure interactions (FSI) are built. In this article such a formulation is analyzed when the fluid is compressible and the fluid is incompressible. The idea is not new but the progress of mesh generators and numerical schemes like the Characteristics-Galerkin method render this approach feasible and reasonably robust. In this article the method and its discretization are presented, stability is discussed by through an energy estimate. A numerical section discusses implementation issues and presents a few simple tests.