Author(s)

S. Ushijima & N. Kuroda

Abstract

This paper deals with a computational method based on multiphase modeling to predict the interactions between free-surface flows and linear elastic objects that undergo finite deformations. In multiphase modeling, a field consisting of gas, liquid and solid phases is treated as the immiscible and incompressible fluid-mixture with different physical properties and the governing equations are derived with one-fluid modeling, while the solid model is derived with objective stress rates and discretization in FEM to deal with the finite deformations. Applying the proposed computational method to experimental results, it was shown that the time histories of the displacements of an elastic plate and the fluid forces caused by wave-induced flows are successfully predicted and that the differences of the fluid forces acting on elastic and rigid plates are reasonably predicted. Keywords: fluid-solid interaction, free-surface flow, elastic body, finite deformation, multiphase model. 1 Introduction The accurate evaluation of the interactions between free-surface flows and the deformations of elastic objects is an important engineering subject, as found in the dynamic responses of floating elastic structures against wave motions and the fluid resistance forces of the flexible plants in river flows. While many investigations have been made for one and two-degree of freedom problems such as the oscillations of a cylinder in uniform flows, the numerical studies for multi-degree of freedom are relatively few, in particular for the interactions between free surface flows and finite deformations of objects.

Keywords

fluid-solid interaction, free-surface flow, elastic body, finite deformation, multiphase model.