Development of Propulsor with Transverse Moving Cascade Wings

为了应用东方桨“Ro”的原理研制一种新型船舶推进器，进行了4年的研究。该推进器具有左右交替横向移动叶栅翼的机构。反过来改变翼叶角度，保持与运动方向相对应的正气流入射角。在横向运动结束时，改变叶片角度和运动方向的运动同时发生。这些运动对推进器各机构产生脉冲冲击和伴随振动，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箱中制造和测试。弹簧工作的翼叶在转动运动方向的同时，也在转动角度时产生剧烈的冲击和振动，这种剧烈的冲击和振动产生的噪声增大了推力和侧向力的测量误差。然后，在1998年，用于改变翼叶角度的弹簧被转换成步进电机。这减少了转弯时的冲击和振动，以至于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，将翼叶的截面由翼形改为翼型。因此，最高效率超过70%。在1999年，机器被安装在4米长的模型船上进行自推进试验。但是由于模型船的滚动和振动大，我们在自推进试验中失败了。2000年对该机进行了改进，通过计算机控制运动和转向的伺服电机系统，实现了运动方向和翼叶角度的软转向。我们希望在不久的将来研制出这种新型推进器。

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.