Viscous Flow Computation around the Wigley Hull with the Maneuvering Motion using the Inertial Coordinate System on the Non-inertial Grids

Abstract

Computational Fluid Dynamics (CFD) technique for ship hydrodynamics has been well developed with advanced capabilities for resistance and propulsion, seakeeping, and maneuvering. The Authors’ laboratory (Laboratory 3 of Department of Naval Architecture and Ocean Engineering in Osaka University) specializes in resistance and propulsion field and has carried out several simulations based on the CFD code in non-inertial ship-fixed coordinates system. The purpose of this research is to transform the present computation code to the one in inertial coordinate and to investigate the flow field around the Wigley hull for several motions up to three degrees of freedom (3 DOF). The transformed code is simulated on the flat plate initially and the nature of the flow field is investigated and confirmed with the hydrodynamics theory. Then, the wigley hull motions are simulated in several ways such as; uniform motion, pure yaw and circular motion test. The features of the flow field and hydrodynamic forces acting on the hull are discussed based on the computed results. Finally, the propeller effect is implemented behind the wigley hull using the body-force concept by the quasi-steady infinite bladed Blade Element Theory and a propulsion characteristic is observed. The transformed computation code in inertial coordinate is found to be much easier to simulate the different kinds of maneuvering motions compared to the code in non-inertial system and this paper covers the detailed transformation steps and the discussions on the computation results of different motions.