抄録
In the previous paper, authors presented experimental and theoretical data on open water characteristics of two side thrusters which impellers have the forward skew (type (A)) and the backward skew (type (B)).
In this report, cavitation characteristics and blade stress of these two side thrusters are investigated theoretically and experimentally. Cavity extent on the impeller blades was estimated by the propeller lifting surface theory. Then, cavitation tests were performed by using the impeller models with the duct in the cavitation tunnel. These results show that the cavity extent on the impeller blades is similar comparing these two impellers. But, the tip vortex cavitation of impeller (B) is much stronger than that of impeller (A), which causes more severe noise and vibration. The finite element method was applied for the stress analysis of the impeller blades. The stress level of impeller (B) was normal, but slightly high stress, which was acceptable, was found on the blade of impeller (A) near the leading edge of 0.7 R-0.8 R.
