Influence of drift angle on the propulsive efficiency of a fully appended container ship (KCS) using Computational Fluid Dynamics

To estimate the powering and manoeuvring performance of the ship in a real seaway, it is essential to accurately determine forces acting on the hull, propeller, rudder and their interaction effects when operating at an angle of drift. The rotating propeller alters the fluid flow around the upstream hull and the downstream rudder. Likewise, when a non-zero drift or rudder angle is applied, significant crossflow is generated across the propeller plane, changing the wakefield and the actual performance of the propeller. A study is conducted to analyse the hull-propeller-rudder interaction of the benchmark KRISO Container Ship (KCS) in calm water using Computational Fluid Dynamics (CFD). The KCS is studied at drift angles of -10 degrees, 0 degrees and +10 degrees, combined with a series of rudder angles (-35 degrees to +35 degrees), which can represent quasi-static phases of an actual ship manoeuvre. The propeller is modelled using two body force models, Blade Element Momentum Theory and the Yamazaki model. Good agreement is found between experimental and numerical results when predicting hull forces and wave patterns at drift, providing a good reference for experimental measurement of the hull and its appendage forces at drift and future validation of actual dynamic manoeuvring simulations.