抄録
In this paper we deal with the free surface effect on the hull-propeller-rudder interactions. By using the model ship hull N-S. 1(L=2.55 m), the propeller MP-1 and the rudder model MR-4, several experiments are performed. They are the resistance test of the hull, the propeller open test, the self-propulsion test and the rudder resistance measurement at the self-propelled and the open water conditions. On the other hand, we attempt to elucidate the mechanism of the free surface effect on the hull-propeller-rudder interactions by using the source-represented hull, the simple sink propeller and the rudder model. The sink propeller model is generalized so as to represent the accelerated flow and the rotating flow in the propeller race. The rudder is represented by the source and the vortex which are distributed in the rudder center plane. Calculations are performed taking into account the wave effects for the combination of the hull, the propeller and the rudder used in the experiments. Following results are obtained. 1) The thrust deduction and the effective wake fractions and the rudder resistance vary with Froude number. 2) The presence of the rudder increases the effective wake fraction compared with the value in the hull-propeller interactions. 3) The humps and hollows of the rudder resistance correspond to those of the hull resistance.
