Master thesis : Development of Methodology for Predicting Marine Vessel Turning Radius with Overset Grid Technique using CFD Solver

Abstract

Finding the turning radius of a ship at an early stage is an interest for both naval architects. The most accurate and lowest error prediction at design stage is to conduct a scale model test. The development of computational method allows to conduct such multidomain calculations with allowable deviations from real result. Many empirical, semi-empirical formulations are available for large displacement vessel with some limited value application but no formulation for high speed or medium speed vessel are not available. In order determine this factor, researchers focus on finding the pressure force variation and fluid interaction with hull at high speed. The rudder shape, size, stern flow, propeller side force, transverse hull moment was studied along with coupled 6 DOF equation and inboard outboard roll angle. The aim of the study is to find the turning radius for these medium or high-speed vessel with overset grid technique using computational fluid dynamics. A 6 DOF coupled equation was considered as the real behavior is coupled with different DOFs. K omega SST model was used as turbulence model as k – ω model is used near the solid wall and k – model is used away from the wall by using a blending function. The model also considers the turbulent shear stress transport. The research is focused on finding the appropriate physical behavior for high-speed vessel and combining that behavior on a CFD solver in order to predict turning radius as accurate as possible. With an optimized mesh, a closer prediction was found using a bare hull for the simulation.