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: displa cement-based formulations and potential-based formulations. Although d isplacement-based formulations have been used widely, the methods suff er from the presence of spurious circulation modes and locking behavio r. Potential-based formulations are inherently irrotational and do not have the difficulties of the displacement-based formulations. Neverth eless most of the applications of these methods are still limited to c ases with relatively small motions. We introduce in this paper an arbi trary Lagrangian-Eulerian formulation using the velocity potential and the density as fluid variables. The formulation can be applied to pro blems in which the fluid undergoes very large boundary motions and can be used equally well for both compressible and incompressible fluids.