Partially rotating grid method for self-propulsion calculations with a double body ship model

In this paper, partially rotating grid method for predicting self-propulsion characteristics using a double body ship model approach is presented. Partially rotating grid method combines a full-discretized temporal-domain rotating propeller approach with locally introduced non-inertial equation system to reduce overall computation time. Verification and validation of the method are performed in this paper. Numerical self-propulsion simulations are conducted for a single-screw KRISO container ship both in model and full-scale. Obtained results are analyzed in terms of integral (propulsion factors) and local (velocity field) flow characteristics with a focus on ship-propeller interaction and scale effects. To better understand propeller performance and ship-propeller interaction effects, variation of a single blade KT, KQ, and KT/KQ values during one period of rotation are analyzed. The introduced partially rotating grid method proved to accurately predict the integral and local flow characteristics while reducing overall computation time, at cost of reduced accuracy.