RANS CFD seakeeping simulation for an 82k DWT vessel in head and oblique waves

Abstract

Numerical seakeeping simulation of an 82k DWT vessel is carried out to investigate its ship motions and added resistance in head waves and oblique waves. By applying the Reynolds-Average Navier-Stokes (RANS) calculations, both viscous and rotational effects are included in current seakeeping simulation. In this study the Navier-Stokes and continuity equations are the governing equations and they are discretized by finite volume method. The free surface is tracked by volume of fluid (VOF) method, volume fractions were used together with fluid’s incompressibility. The turbulence model was k - ω SST. In this simulation, Wave Forcing technic is applied to reduce the size of the computational domain and reduce the computing resources needed. The solution of the 3D Navier-Stokes equations is forced towards a solution in the boundary zone, this forcing also eliminates problems that are associated with reflections of surface waves at boundaries. The validation studies are carried out by comparing the current simulations’ results with towing tank experiments. This study established the viscos method with 3 degree of freedom for evaluating 82k DWT vessel’s seakeeping performance. The authors also gave the suggested length of the wave forcing area for the 82k DWT ship.