AN ARBITRARY LAGRANGIAN-EULERIAN VELOCITY POTENTIAL FORMULATION FOR FLUID-STRUCTURE INTERACTION

Finite clement formulations for fluid-structure interaction, assuming an inviscid fluid, can be classified into two major categories: displacement-based formulations and potential-based formulations. Although displacement-based formulations have been used widely, the methods suffer from the presence of spurious circulation modes and locking behavior. Potential-based formulations are inherently irrotational and do not have the difficulties of the displacement-based formulations. Nevertheless most of the applications of these methods are still limited to cases with relatively small motions. We introduce in this paper an arbitrary Lagrangian-Eulerian formulation using the velocity potential and the density as fluid variables. The formulation can be applied to problems in which the fluid undergoes very large boundary motions and can be used equally well for both compressible and incompressible fluids.