Numerical simulation of fluid–structure interaction problems on hybrid meshes with algebraic multigrid methods

Fluid–structure interaction problems arise in many fields of application such as flows around elastic structures and blood flow in arteries. The method presented in this paper for solving such a problem is based on a reduction to an equation at the interface, involving the so-called Steklov–Poincaré operators. This interface equation is solved by a Newton iteration, for which directional derivatives involving shape derivatives with respect to the interface perturbation have to be evaluated appropriately. One step of the Newton iteration requires the solution of several decoupled linear sub-problems in the structure and the fluid domains. These sub-problems are spatially discretized by a finite element method on hybrid meshes. For the time discretization, implicit first-order methods are used for both sub-problems. The discretized equations are solved by algebraic multigrid methods.

► We formulate a Newton based fluid–structure interaction solver with a segregated approach.
► We develop finite element discretization on hybrid meshes for the linear elasticity and fluid sub-problems.
► We construct a stabilized P1P1–P1P1 hierarchy of an AMG solver for the fluid problem on hybrid meshes.