プロペラのスキューと伴流分布がプロペラ変動圧力に及ぼす影響について

抄録

This paper deals with the influences of skew back of propeller and wake distributions on hull pressure fluctuations caused by cavitating propellers. At first, three model propellers with different skew angles were tested in the cavitation tunnel in the same model wake distribution. The extent of cavity, the cavity thickness distributions and the pressure fluctuation on the flat plate above the propeller were measured and compared with the unsteady lifting surface theory. Secondly, the influence of the scale effect of wake distributions on the propeller cavtation and the hull pressure fluctuation were investigated by the same calculation method comparing the full scale and model scale data of Seiun-Maru. The results of the experiments showed the increase in the cavity thickness near the propeller tip passing through the high wake region as the increase of skew angle. The calculations estimated thicker cavity thickness near mid span region and thinner cavity thickness near tip region than the experiments. But the thicker cavity thickness due to the skew back could not be simulated by the calculations. The pressure amplitudes of the full scale ship could reasonably be estimated taking the scale effect of wake distributions into account, execpt for the case of highly skewed propeller.