直升机旋翼桨尖形状初步研究

直升机旋翼桨尖形状由简单的矩形改变为先进形状可改善直升机性能,降低旋翼产生的振动和噪声。本文在简介国内外直升机旋翼桨尖形状研究情况的基础上,着重叙述近期在南京航空学院直升机技术研究所旋翼台上进行的四种不同桨尖形状旋翼悬停性能初步试验研究,给出了试验结果及其分析。试验的四种桨尖是:(a)矩形桨尖;(b)后掠(或直线后掠)桨尖;(C)尖削桨尖,(d)后掠抛物桨尖。对于(b)、(c),后掠或尖削从 r=O.9R 处开始,而(d)后掠抛物从 r=o.85R 开始。文中给出了试验所得桨尖对拉力、功率、悬停效率的影响曲线,并进行了相应分析,试验及分析结果表明,桨尖形状的改进确实能提高旋翼的悬停效率,改善性能。尖削形状的旋翼拉力可提高6%以上,而悬停效率亦可提高5%。

A PRELIMINARY STUDY ON HELICOPTER ROTOR BLADE TIPS SHAPES

Advanced rotor blade tip shapes may largely improve heli-copter performance and reduce the vibration and noise generated by therotor.In this paper,the research into the effect of helicopter rotor bladetip shapes is briefly introduced.Then,the recent experimental studiesof hover performance of two meter diameter model rotor with fourdifferent tip configurations,in the Rotor Model Test Facility of theResearch Institute of Helicopter Technology,Nanjing Aeronautical In-stitute,is described in detail, and the test results and analyses are pres-ented.The four blade tips tested are(a)a rectangular tip,(b)a swepttip,(c)a tapered tip,and(d)a parabolic swept tip.The modelledshapes occupied the last 10% of the rotor radius for(b)and(c),and15% for(d).The effects of the tip shapes on thrust,power and hoverefficiency are discussed.The test results show that the modelled rotorblade tip shapes may really resulted in a large improvement in rotorhover performance.The tepered tip increased the rotor thrust by more6% and figure of merit by about 5%.