スキュー分布の異なる可変ピッチ式サイドスラスタの性能

第1報 : サイドスラスタ単独性能

抄録

Impellers of controllable pitch side thrusters are operated under the condition of the pitch angle twisted largely from the design geometory (0° (zero) pitch angle). Therefore, it is very important to consider changes of the geometrical shapes with the twist of impeller blades and their performance characteristics in the design of controllable pitch side thrusters.
In the present paper, two impellers of the forward skew type (A) and the backward skew type (B) are designed and the above-mentioned changes of the geometrical shapes with the twist of impeller blades are calculated and their open water characteristics are investigated theoretically and experimentally. The open water characteristics of these two impellers were calculated by using the propeller lifting surface theory. Then, open water tests were performed by using the impeller models with and without the duct in the towing tank.
These results show that the camber of the blade section becomes minus largely with the twist of impeller blades and the open water characteristics with and without the duct deteriorate in case of the backward skew type (B) comparing with the forward skew type (A).