Methodology for Comparing Coupling Algorithms for Fluid-Structure Interaction Problems

Abstract

The multi-physics simulation of coupled fluid-structure interaction problems, with disjoint fluid and solid domains, requires one to choose a method for enforcing the fluid-structure coupling at the interface between solid and fluid. While it is common knowledge that the choice of coupling technique can be very problem dependent, there exist s no satisfactory coupling comparison methodology that allows for conclusions to be drawn with respect to the comparison of computational cost and solution accuracy for a given scenario. In this work, we develop a computational framework where all aspects of the computation can be held constant, save for the method in which the coupled nature of the fluid-structure equations is enforced. To enable a fair comparison of coupling methods, all simulations presented in this work are implemented within a single numerical framework within the deal.ii [ 1 ] finite element library. We have chosen the two-dimensional benchmark test problem of Turek and Hron [ 2 ] as an example to examine the relative accuracy of the coupling methods studied; however, the comparison technique is equally applicable to more complex problems. We show that for the specific case considered herein the monolithic approach outperforms partitioned and quasi-direct methods; however, this result is problem dependent and we discuss computational and modeling aspects which may affect other comparison studies.