Development of Propulsor with Transverse Moving Cascade Wings

本课题是应用东方“Ro”型双桨原理研制新型船舶推进器的研究。推进器具有使叶栅翼交替地向左和向右横向移动的机构。通过改变翼片的角度，使气流的正入射角与运动方向一致。在横向移动结束时，发生改变叶片角度和移动方向的运动。这些运动会对推进器各机构产生冲击和跟随振动，对推力和侧向力的测量产生不利影响。1997年，这种新型推进器的原始机器在横滨国立大学的拖曳水池中制造和测试。在弹簧作用下，叶片在转向运动方向和同时转角的瞬间会产生剧烈的冲击和振动，这种剧烈的冲击和振动所产生的噪声增加了推力和侧向力测量的误差。1998年，将用于改变机翼叶片角度的弹簧转换为步进电机。这减少了转弯时的冲击和振动，因为推力和侧向力都是可测量的。分析这些测得的力，最高效率为60%。然后，为了提高效率，将机翼叶片的截面由卵形改为翼型。因此，最大效率超过70%。1999年，该机被安装在4米长的船模上进行自航试验。但由于模型船横摇和振动过大，在自航试验中失败。在2000年对该机进行了改进，通过计算机控制伺服电机的运动和转动系统，实现了叶片运动方向的软车削和叶片角度的软车削。我们希望在不久的将来能研制成功这种新型推进器。

This research has been carried out for 4 years in order to develop a new propulsor of a ship by applying the principle of the oriental scull "Ro". The propulsor has the mechanism of transversely moving cascade wings towards alternatively left and right. The angle of wing blades is changed reversely to keep the positive incident angle of flow corresponding to the moving direction. Motions of changing the blade angle and the direction of moving simultansovsly take place at the end of transverse moving. These motions give rise to the impulsive shock and following vibration to all mechanism of the propulsor, which have bad influence on measurement of thrust and lateral force. In 1997 the original machine of this new propulsor was manufactured and tested in the towing tank of Yokohama National University. The severe shock and vibration happened at the moment of turning the direction of moving and simultaneous turning the angle of wing blades which was worked by the spring, The noise due to such severe shock and vibration increases the error of measurement of thrust and lateral force. Then, in 1998, the spring for turning the angle of wing blades was converted into the stepping motor. This decreased the shock and vibration at turning so much as both thrust and lateral force were measurable. Analyzing such measured forces, the highest efficiency was 60%. Then, to get the efficiency up, the section of wing blades was changed from ogival to aerofoil. Thus the maximum efficiency exceeded 70%. In 1999 the machine was installed on the 4 meters long model ship to carry out the self propulsion test. But we failed in the self propulsion test due to large rolling and vibration of the model ship. In 2000 we try to improve the machine to realize soft turning of direction of motion and soft turning of the angle of wing blades by computer control of servomotors systems for moving and turning. We hope to succeed in developing the new propulsor in near future.