耦合高效配平策略的旋翼气动特性分析方法  

Analytical method of rotor aerodynamic characteristics by coupling a high-efficiency trim strategy

作　　者：叶舟[1] 史勇杰[1] 徐国华[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：《航空动力学报》2017年第4期882-889,共8页Journal of Aerospace Power

基　　金：国家自然科学基金(11302103);江苏省研究生培养创新工程(KYLX15_0238)

摘　　要：建立了一个耦合高效配平策略和计算流体力学(CFD)技术的旋翼气动特性分析方法.采用CFD求解器进行雅克比矩阵和旋翼流场的计算,建立了一个包含直接配平法的旋翼气动特性分析平台;引入差量法思想对配平策略进行简化,发展了一种差量配平法,解决了直接配平法中雅克比矩阵计算效率低下的问题,显著缩短了计算时间.旋翼流场求解中控制方程采用Navier-Stokes方程,空间离散格式选取2阶迎风Roe格式,时间推进采用隐式lower-upper symmetric Gauss-Seidel(LU-SGS)格式,湍流模型为Baldwin-Lomax(B-L)模型.分别采用建立的基于直接配平方法和差量配平方法的气动特性分析平台对AH-1G和Helishape 7A直升机的旋翼进行了配平计算和研究,对比分析了两种配平方法的计算效率和精度及背景网格的网格量对配平结果的影响.结果表明:与直接配平法相比,耦合差量配平法的气动特性分析方法计算圈数更少,可节省至少60%的计算时间;使用疏化的背景网格虽然不利于捕捉流场细节,但是可以在兼顾配平结果准确性的同时,降低配平计算代价,提高旋翼配平和流场计算的效率.A numerical analytical methodology was developed for aerodynamic character- istics analysis of helicopter rotor by coupling a high-efficiency trim strategy and the computa- tional fluid dynamics （CFD） technology. Firstly, using the CFD solver to calculate the Jaco- bin matrix and rotor flowfield, an analytical methodology with direct trim method was estab- lished. Then, by employing the ＂delta method＂, the computation of Jacobin matrix was sim- plified and a delta trim method was developed such that the calculation time of rotor perform- ances was significantly decreased. For the calculation of rotor flowfield, the Navier-Stokes e- quation was selected as the governing equation, and a second-order upwind scheme, i.e. Roe scheme, was used for spatial discretization. Implicit lower-upper symmetric Gauss-Seidel （LU-SGS） scheme was adopted for time marching, and the Baldwin-Lomax （B-L） model was selected as the turbulence model. The computation efficiency and accuracy of the ＂delta＂ trim method was compared with that of the direct trim method by numerical calculations based on experimental states of ＂AH-1G＂ and ＂Helishape 7A＂ rotors. In addition, effects of the back- ground grid quantity on rotor trimming were also analyzed. It is shown that, compared with the direct trim method, the delta trim method can save at least sixty percent of computing time to make the trimming procedure converged. A coarse background grid is not helpful for the capture of flowfield details, but has nearly the same accuracy as a refined background grid in the calculation of rotor control settings; furthermore, the computing efficiency of a coarse grid is higher than that of a refined grid due to the lower grid quantity.

关 键 词：旋翼 配平 气动特性 NAVIER-STOKES方程 直升机 

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]