Evaluation of manoeuvring coefficients of a self-propelled ship using a Blade Element Momentum propeller model coupled to a Reynolds averaged Navier Stokes flow solver

Alexander Phillips1, Stephen R. Turnock1, Maaten Furlong2 1 School of Engineering Sciences, University of Southampton 2National Oceanography Centre, Southampton Abstract The use of an unsteady Computational Fluid Dynamic analysis of the manoeuvring performance of a self-propelled ship requires a large computational resource that restricts its use as part of a ship design process. A method is presented that significantly reduces computational cost by coupling a Blade Element Momentum Theory (BEMT) propeller model with the solution of the Reynolds Averaged Navier Stokes (RANS) equations. The approach allows the determination of manoeuvring coefficients for a self-propelled ship travelling straight ahead, at a drift angle and for differing rudder angles. The swept volume of the propeller is divided into discrete annuli for which the axial and tangential momentum changes of the fluid passing through the propeller are balanced with the blade element performance of each propeller section. Such an approach allows the interaction effects between hull, propeller and rudder to be captured. Results are presented for the fully appended model scale self propelled KVLCC2 hull form under going static rudder and static drift tests at a Reynolds number of 4.6x10 acting at the ship self propulsion point. All computations were carried out on a typical workstation using a hybrid finite volume mesh size of 2.1x10 elements. The computational uncertainty is typically 2-3% for side force and yaw moment.