Immersed boundary method: performance analysis of popular finite element spaces

Abstract

The aim of this paper is to understand the performances of different finite elements in the space discretization of the Finite Element Immersed Boundary Method. In this exploration we will analyze two popular solution spaces: Hood-Taylor and Bercovier- Pironneau (P1-iso-P2). Immersed boundary solution is characterized by pressure discontinuities at fluid structure interface. Due to such a discontinuity a natural enrichment choice is to add piecewise constant functions to the pressure space. Results show that P1 + P0 pressure spaces are a significant cure for the well known “boundary leakage” affecting IBM. Convergence analysis is performed, showing how the discontinuity in the pressure is affecting the convergence rate for our finite element approximation