螺旋桨前置自由旋轮的初步研究

A Preliminary Investigation on the Effectiveness of a Free Wheel Mounted in Front of Screw

本文提出一种新的船舶节能和减振装置,即在螺旋桨的前方安装同轴线自由旋转的叶轮,可使伴流均匀化和产生预旋,同时旋轮还发出附加推力.文中给出了叶轮和推进器叶切面的速度多边形图和水动力表达式;分析了旋轮的叶片数、直径和转速对效率的影响.此外提出了旋轮设计的简化方法.最后,介绍了一个螺旋桨带前置旋轮的模型敞水试验,结果表明敞水效率比单独螺旋桨模型相对提高3%～4%.

A novel free wheel assembled coaxially with and mounted in front of ship propeller is proposed. This new arrangement is capable of equalizing the wake fields of ship stern, making a pre-swirl inflow of screw and producing an extra thrust. Hence it will be an energy-saving and vibration-reducing device.The velocity polygon of the blade section and the expressions for the hydrodynamic forces of the wheel and propeller are given. The effects of wheel blade number, diameter and rotational speed on efficiency are analyzed and a simplified design method of wheel is suggested. Model tests per formed on screw with free wheel show that the open water efficiency of model with this device is 3%~4% higher than that with simple screw.