抄録
This paper presents a theoretical calculation method of propulsive performance of ship. At first, we represent the ship hull in the double-body flow by the source distribution on the hull surface, and the propeller by the circulation distribution on the propeller plane and the rudder thickness by the source distribution and the rudder load by the vortex distribution on the rudder center plane. Then above singularity distributions are determined by each boundary condition. Using these singularities, the flow field and the forces such as thrust and torque, rudder drag are calculated. As the next step, we calculate the wave flow around ship hull, the propeller and the rudder. Here we use the Rankine Source method. Then we can obtain the hull wave-making resistance and the wave flow including pressure distributions on the hull in the potential flow field. Next we calculate, on the basis of potential flow field, the effective wake distribution just before the propeller plane. Our wake calculation method is based on the thin boundary layer approximation and belongs to the integral method. This effective wake distribution becomes the input data of the propeller inflow in the potential flow calculation. By an iterative procedure, the self-propelled state of ship is attained and the propulsive performance of ship is obtained. We perform the calculations for Wigley and SSPA720 hulls with a propeller and a rudder and compare the calculated results with experimental ones. The effective wake and thrust deduction fractions obtaind by present calculation agree well with experimental ones.
