COMPUTATIONAL MODELLING OF SEMI-DISPLACEMENT HULL IN DEEP AND SHALLOW WATER

Abstract

Fast marine vessels often operate in the semi-displacement mode when hydrodynamic lift plays an increasingly important role and hull trim and sinkage become speed-dependent. The shallow-water effects may also alter hydrodynamic characteristics of such hulls. In this study, computational fluid dynamics simulations have been carried out for a high-performance semi-displacement hull. Numerical results were validated against deep-water test data over a broad speed range. Shallow-water simulations were conducted at three speeds ranging from the fast displacement to semi-planing regimes at the critical depth-based Froude number and three shallow water depths. The hull hydrodynamic characteristics and associated wave patterns are presented. The appearance of a solitary wave and drag hump at a lower speed and reduction of drag in very shallow water are observed. These results can be useful for designers of semi-displacement vessels.