直升机旋翼/尾桨/垂尾气动干扰计算研究  

Computational research on aerodynamic characteristics of helicopter main-rotor/tail-rotor/vertical-tail interaction

作　　者：叶舟[1] 徐国华[1] 史勇杰[1] 

机构地区：[1]南京航空航天大学直升机旋翼动力学国家级重点实验室,南京210016

出　　处：《航空学报》2015年第9期2874-2883,共10页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(11302103);航空科学基金(20135752055)~~

摘　　要：建立了一个基于计算流体力学(CFD)技术的直升机旋翼/尾桨/垂尾气动干扰分析方法。在该方法中,选取Navier-Stokes方程为控制方程,使用二阶迎风的Roe格式进行空间离散,并选取隐式LU-SGS(Lower-Upper Symmetric Gauss-Seidel)格式进行时间推进,湍流模型为B-L(Baldwin-Lomax)模型;为了实现旋翼、尾桨和垂尾网格之间的流场信息交换,采用运动嵌套网格方法。应用所建立的方法,对Helishape 7A旋翼和Lynx直升机尾桨进行了算例计算,并与试验数据进行对比,验证了方法的正确性。着重针对旋翼/尾桨干扰特性进行了计算,并进一步计入垂尾的干扰,对垂尾/尾桨干扰以及旋翼/尾桨/垂尾干扰特性进行了研究,分析了旋翼、尾桨和垂尾相互干扰的规律。结果表明:对于不同的垂尾/尾桨构型,阻塞面积越大,对应的尾桨拉力也较大,但尾桨和垂尾获得的净拉力却减小,且不同阻塞面积下,推力式构型尾桨比拉力式尾桨具有更大的净拉力;然而,在前飞过程中,直升机垂尾对旋翼与尾桨干扰的影响很小。A computational method based on computational fluid dynamics （CFD） technology is developed for helicopter main-rotor/tail-rotor/vertical-tail interaction analysis. In the present method, Navier-Stokes equations are utilized as the control equations. For the spatial and time discretization, the second-order upwind Roe scheme and implicit LU-SGS （Lower-Upper Symmetric Gauss-Seidel） scheme are used respectively, and the B-L （Baidwin-Lomax） model is used as the turbu- lence model. Moving embedded grid method is applied to exchanging the flowfield information among the grids of main-rotor, tail-rotor and vertical-tail. By the method developed, example calculations on the flowfield of well-known Helishape 7A rotors and Lynx tail rotors are performed, and the validity of the present method is demonstrated by comparing the calculated results with available experimental data. Then, numerical simulations for main-rotor/tail-rotor aerodynamic interference are made. Furthermore, taking vertical tail interaction into consideration, tail-rotor/vertical-tail and main-rotor/tail-rotor/verti- cal-tail interaction calculations are conducted to investigate the interaction mechanism between main rotor, tail rotor and vertical tail. It is shown that, for different vertical-tail/tail-rotor configurations, a larger blockage area always leads to a greater tail-rotor trust, but a smaller clean trust of vertical tail and tail rotor. In addition, the clean tail-rotor trusts of ＂push configuration＂ are always higher than those of the ＂pull configuration＂ for different blockage areas. It is also shown that, vertical tail has little influences on main-rotor/tail-rotor interaction in forward flight.

关 键 词：气动干扰 嵌套网格 NAVIER-STOKES方程 直升机 计算流体力学 

分 类 号：V211.52[航空宇航科学与技术—航空宇航推进理论与工程]