Development of Propulsor with Transverse Moving Cascade Wings

这项研究已进行了4年，目的是应用东方双桨“Ro”的原理，研制出一种新型的船舶推进器。推进器具有横向移动级联翼向左右交替移动的机制。机翼叶片角度反向改变，以保持气流的正入射角度与运动方向相对应。横向运动结束时，同时发生改变叶片角度和运动方向的运动。这些运动会对推进器的所有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型机在横滨国立大学的拖曳水箱中进行了制造和试验。强烈的冲击和振动发生在扭转运动方向和同时转动弹簧工作的翼片角度的时刻，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的测量误差。然后，在1998年，用于转动机翼叶片角度的弹簧被转换为步进电机。这减少了转弯时的冲击和振动，因为推力和侧向力都是可以测量的。分析这些测得的力，最高效率为60%。然后，为了提高效率，将机翼叶片的截面从椭圆形改为机翼。因此，最高效率超过70%。1999年，该机被安装在4米长的模型船上进行自航试验。但由于模型船横摇和振动较大，我们没有通过自航试验。2000年，我们对该机床进行了改进，通过运动和转向伺服电机系统的计算机控制，实现了运动方向的软转动和翼片角度的软转动。我们希望在不久的将来成功地研制出新型推进器。

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.