In this paper, CFD simulation results of a full form ship in ballast condition advancing in waves are validated by the comparison with experimental data over a range of wave conditions to verify its capability to predict the sea-keeping performance of full form ships. CFD simulations are conducted using WISDAM-X code which is capable of unsteady RANS calculations in arbitrary wave conditions. CFD simulation results are compared with the experimental data for a SR221 hull form, which is a representative of a large tanker hull form. The experiment is conducted with a 4.6m model of SR221 in the towing tank. The experiment is conducted in regular waves with a wide range of conditions in terms of wave length and wave height. Simulated results correlate fairly well with the experimental data in ship motions, added resistance and hull-surface pressures. Detailed examination of computed flow structures clarifies the mechanism of resistance increase due to waves in ballast conditions.
In recent years, importance has been recognized increasingly for the reduction of fuel consumption of ships in a seaway to reduce greenhouse gas emissions from shipping. From a ship design viewpoint, it is of crucial importance to establish reliable prediction methods for ship's propulsive power under realistic wave conditions and to realize their application to the development of hull-forms with superior sea-going capability. In order to achieve these objectives, Japan Marine United Corporation has developed an unsteady CFD ship motion simulation method and has used it as a tool for the development of high-performance hull forms under realistic sea conditions.
Full-form ship's performance in ballast condition in a seaway is significantly deteriorated by the resistance increase due to waves due to strong wave reflection both near the waterline and at the bottom of the bow. Thus, accurate prediction of the resistance increases due to waves is of crucial importance from standpoints of ship design and operation.
