CFD Virtual Testing for Resistance, Wind and Current Loads on a Supply Boat

Abstract

Ship and platforms environmental loads are often predicted by model scale experiments or empirical calculations only. This paper presents the application of a commercial CFD (Computational Fluid Dynamics) software as a numerical approach to calculate the flow around a supply boat considering current, wind loads and fluid resistance determination. Since, owing to many practical situations, free surface effects can be neglected, the above and underwater problems can be uncoupled and independently evaluated, although for higher Froude number cases in the resistance determination the interfacial effects have to be considered. Throughout this paper, the assumptions adopted and the boundary conditions applied are discussed. All meshes were developed on ICEM CFD® and appropriate mesh density studies indicate that meshes with approximately 2 million nodes can represent the experiments accurately. The simulations were conducted using the ANSYS CFX® solver, using Perl scripting for automatic evaluation of multiple run settings and simulation execution at Petrobras Research Center Clusters. The results for each case are compared with either towing tank or wind tunnel experimental data, both harvested at IPT (Instituto de Pesquisas Tecnológicas). The comparison between simulation results and experiments allows the analysis of the present CFD models benefits and limitations, providing guidelines for future similar studies. The overall match between laboratory and virtual tests results supports the expansion of this procedure to other vessels and offshore floating units.