旋翼翼型非定常动态失速响应的计算

Computations of unsteady dynamic stall responses on rotor airfoils

基于旋翼非定常翼型气动模型,给出了计算分离流和深度失速状态下的翼型非定常升力、俯仰力矩的数值计算方法。该方法采用半经验指数响应公式,利用数值离散方法来求解翼型的非定常法向力和俯仰力矩。分别计算了NACA0012和SC-1095翼型上的非定常气动载荷,并与可得到的试验结果进行了对比,验证了方法的有效性。文中还讨论了缩减频率和马赫数对动态失速响应的影响;然后,这个模型被改进以适用于后掠流下的翼型动态失速响应计算,分析了后掠角对翼型动态失速响应的影响。最后,得出了一些结论。

Based on unsteady aerodynamic model, a numerical method has been given to calculate the unsteady lift and pitching moment acting method was expressed on an airfoil of the rotor operating at slightly stall and deep stall conditions in compressible flow. The as a set of semi-empirical indicial response formula, and solved by numerical discretization. As numerical examples, the normal force and pitching moment on NACA0012 and SC-1095 airfoils were calculated, and the comparisons with available experimental data were made so as to show the capability of the present method. The influence of the reduced frequency and Mach number on dynamic stall responses is also investigated. Then, the method was improved to be suitable for the calculations of dynamic stall responses in swept flow, and the swept effects on the airfoil responses were analyzed and discussed. Finally, a few conclusions were presented.