NUMERICAL PREDICTION FOR MOVEMENTS OF A FLOATING OBJECT WITH NON-UNIFORM DENSITY IN FREE SURFACE FLOWS

摘要

This paper deals with a computational method to predict the motions of floating objects which have density distributions in free-surface flows. The density distribution of the floating object is taken into account in the prediction method, since it is closely related to the stability of the initial attitude and its motion. The motions of the floating object and free-surface flows are simultaneously dealt with in the computational method, MICS (Multiphase Incompressible flow solver with Collocated grid System), which enables us to deal with the multiphase field consisting of gas, liquid and solid phases. The floating object is represented by multiple tetrahedron elements with different density one by one, from which the volume-averaged density of a fluid cell is determined through a sub-cell method. The prediction method was applied to the movements of a floating cylinder with non-uniform density and mangrove propagule. As a result of the computations, it was demonstrated that the basic features of their motions are reasonably predicted through the comparison with the experimental results.