Development of Front Wheel to Improve Propulsive Performance of Ship

本文旨在研制一种能提高船舶推进性能的前轮。研究结果如下：（1）制作了22个不同叶片数、直径和螺距的螺旋桨，并在循环水槽中进行了螺旋桨与螺旋桨的相互干扰实验。从这些试验中，我们了解到，我们不能改善系统的推进性能与F. W螺旋桨旋转相反。(2)我们测量了一个工作螺旋桨后的速度场，并证实了一个自由旋转的螺旋桨后的流动被推迟，它增加了前螺旋桨后设置的螺旋桨的推力。(3)我们制作了直径为24cm的8叶4F.Ws，即两个平板F.Ws（F60和F65）和两个等螺距F.Ws（C60和C65），并进行了MP.261（直径为24.08cm）螺旋桨与F.Ws的相互作用实验。(4)在 ...更多信息 在空泡水洞中，进行了MP.105和261螺旋桨与F65螺旋桨以及MP.262螺旋桨与C60螺旋桨的相互干扰试验。然后反向旋转系统（F65 + MP.105和F65 + MP.261）降低了系统的效率。相反，相同的旋转系统（C60 + MP.262）的效率与MP.262的敞水特性相比没有变化。对于空泡，我们证实了在均匀流中，F.W能很好地减小螺旋桨叶片上的空泡面积。(5)在大型船模（长6m）上进行了C60和MP.262的自推进试验，并根据系统（C60 + MP.262）的敞水特性对试验结果进行了分析，证实了F.W在两种航速下对推进性能的改善。(6)采用小型Wigley模型（长2.5m）和6个直径10cm、8片桨叶的平板涡桨进行了变负荷试验，分析了推进性能，证实了只有在相同的旋转系统下，推进效率才有所提高。(7)编制了一个计算程序，计算了具有舵、桨和水的船舶的推进性能，明确了它们之间的相互作用机理。少

We aimed to develop a front wheel (F.W) which improves the propulsive performance of ship. Research results are as follows :(1) We made 22 F.Ws with different number of blades, diameters and pitches, and performed the interaction experiments among a propeller and F.Ws in a circulating water channel. From these tests, we understand that we can not improve the propulsive performance of the system with F.Ws rotating contrary to propeller rotation.(2) We measured the velocity field behind a working propeller, and confirmed that the flow behind a freely rotating propeller was retarded and it increased the thrust of a propeller set behind the front propeller.(3) We made 4F.Ws with 8 blades and 24cm diameter, i.e. two flat plate F.Ws (F60 and F65) and two constant pitch F.Ws (C60 and C65), and performed the interaction experiments among the propeller MP.261 (diameter 24.08cm) and F.Ws. Due to counter rotation of F.W against the propeller, the performance of the system was not improved.(4) In … More a cavitation tunnel, we did the interaction experiments among propellers (MP.105 and 261) and F65 and also between propeller MP.262 and C60. Then the counter rotating systems (F65 + MP.105 and F65 + MP.261) decreased the efficiency of the systems. On the contrary, the efficiency of the same rotation system (C60 + MP.262) was unchanged compared with the open water characteristics of MP.262. As to the cavitation, we confirmed that F.W could fairly decrease the cavitating area on the propeller blade in uniform flow.(5) We conducted the self-proptulsion test of a large ship model (length 6m) with C60 and MP.262, and analyzed the test results based on the open-water characteristics of the system (C60 + MP.262) and confirmed the improvement of propulsive performance due to F.W at two speeds.(6) By using small Wigley model (length 2.5m) and 6 flat plate F.Ws (diameter 10cm, 8 blades), we performed the load varying tests and analyzed the propulsive performance and confirmed the propulsive efficiency increased only in case of same rotation system.(7) After making a computer code to calculate the propulsive performance of ship with F.W, propeller and rudder, we made clear the mechanism of interactions among them. Less