Numerical Simulations for High Speed Ships in Deep and Shallow Water with Sinkage and Trim

Abstract

The present paper presents a CFD estimation result for the resistance perform of a high speed ship advancing in deep and shallow water with sinkage and trim. The numerical results are obtained using a RANS based general ship hydrodynamic code, WAVIS which uses a cell-centered finite volume method for the discretization of the governing equations. The free surface is captured using a two-phase level-set method and a realizable k-ε model is used for turbulence closure. Sinkage and trim are computed at one computational time step and ap-plied in the succeeding time step through a re-gridding procedure, which is performed with an interval of a fifth to tenth of the total number of iteration for simulation. The computations have been carried out at selected five speeds of the ship and in varying water depths to predict the shallow water effects on the resistance and the attitude of the ship. The present numerical results for resistance, sinkage and trim in deep water are first validated with available experimental results. The shallow water results have shown a very reasonable accordance with the patterns of resistance, sinkage and trim in finite depth waters as found in the literature.