提高小型无人机螺旋桨效率的工程方法

Practical Measures for Raising Propeller Efficiency of Low Speed Mini UAV

提高螺旋桨效率一直是螺旋桨设计中的关键问题。常规的螺旋桨设计理论主要是针对大型飞机的。小型低速无人机螺旋桨的工作特点从多方面制约了螺旋桨效率的提高。本文基于多种型号无人机螺旋桨的研制实践 ,从选用高性能桨型、放宽螺旋桨桨尖马赫数的上限、合理匹配螺旋桨的吸收功率与发动机的输出功率、精选桨材、提高加工工艺质量、加强表面防护等方面 ,总结出一套提高小型低速无人机螺旋桨效率的工程手段。风洞试验与飞行实践证实了其有效性与可靠性。

How to raise the propeller efficiency has been the key problem in airplane propeller design. The conventional theory of propeller design is mainly for large aircraft. However, for a low speed mini UAV (Unmanned Air Vehicle) the propeller has such features as high rotating speed, relatively small diameter, low forward speed, fixed pitch and wooden blade; all these features adversely affect propeller efficiency. Based on our experience in developing a series of different kinds of low speed mini UAV, we performed in a number of years repeated trade-offs and finally evolved optimized practical measures to overcome the influence of the above-mentioned unfavorable factors, thus raising the propeller efficiency to some extent. The following six practical measures are described: selecting high performance blade-foil, lifting the upper limit of Mach number at propeller tip, matching the absorbing power of propeller with the output power of engine, selecting high quality blade material, improving manufacturing technology, and blade surface reinforcement. The results of wind tunnel experiments and flying tests show that with the aid of these practical measures, the propeller efficiency of a low speed mini UAV can be increased by 5-10 percent in general.