直升机环量控制尾梁截面形状分析

An analysis of cross section of helicopter tail boom for NOTARTMsystem

基于二维可实现k-Epsilon湍流模型模拟计算了直升机环量控制尾梁上的升力,并与试验结果进行了对比,计算结果与试验结果之间显示出了可接受的吻合度。利用已验证的数值计算方法和网格划分方法,分别计算了三组不同截面形状的环量控制尾梁在不同几何参数(喷射角、缝位角、基准直径和狭缝数量)或试验条件(喷射气流速度、下洗流速度)下的升力。结果显示,通过优化尾梁截面形状和狭缝相对位置,引导气流在截面曲率较大的位置处脱离壁面,可以提高尾梁升力并增强附壁气流的稳定性。模拟计算结果还揭示了提高下洗流速度和降低狭缝喷射角可以提高优化尾梁截面和狭缝相对位置的效果。

Lift on circulation control circular cylinder is calculated via numerical simulations based on 2D realizable k-Epsilon viscous model and compared with experimental data. The simu- lation result shows acceptableagreement with test data. With the proved grid and simulation method, lift on series of three different types of cross sections with different geometry parame- ters（blow angles, referenced position of slot, referenced circular cylinder diameters, and number of slots） or testing parameters（jet flow velocities, down wash flow velocities） is simulated. The results show that lift on circulation control tail boom could be increased with same power con- sumption, the stability of the attached flow could be enhanced by optimizing the shape of the cross section of the tail boom and the position of the slot（s） relative to the large curvature zone of the cross section where the attached flow is supposed to separate from the surface. It is also re- vealed that larger down wash velocity or smaller blow angle helps increasing the effect of optimi- zing of the shape and relative position of the slot（s）.