旋翼翼型非定常来流动态失速力矩及阻尼特性研究  

Investigation of Moment and Damping Characteristics of Rotor Airfoil Dynamic Stall Under Unsteady-Freestream

作　　者：高远 赵国庆[1] 井思梦 招启军[1] 陆凡[1] GAO Yuan;ZHAO Guoqing;JING Simeng;ZHAO Qijun;LU Fan(National Key Laboratory of Helicopter Aeromechanics,Nanjing University of Aeronautics&Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学直升机动力学全国重点实验室,南京210016

出　　处：《南京航空航天大学学报(自然科学版)》2025年第2期275-284,共10页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：国家自然科学基金(12072156);江苏高校优势学科建设工程资助项目。

摘　　要：动态失速现象严重制约了直升机的飞行性能,文中为揭示非定常来流状态下气动力矩及阻尼特性变化的机理,采用有限体积方法、运动嵌套网格技术、Roe⁃MUSCL格式和S⁃A湍流模型构建旋翼翼型非定常流场数值模拟方法。在此基础上,对SC1095翼型及其变形翼型在定常/非定常来流⁃变迎角状态下的非定常气动特性进行数值模拟。对比分析计算结果发现:动态失速涡(Dynamic stall vortex,DSV)的形成与对流是造成力矩失速的主要原因;后缘涡(Trailing edge vortex,TEV)导致DSV从翼型表面抬起是引起低头力矩系数峰值的主要因素;在本文的研究范围内,定常来流状态下翼型失速方式为前缘失速,非定常来流状态下受气动外形影响翼型失速方式存在前缘失速和后缘失速,其DSV的对流速度及强度显著小于定常来流状态,而各自来流状态下不同外形翼型DSV的对流速度差异较小。在定常、非定常来流状态下,翼型弯度、厚度和前缘半径的变化会引起力矩发散相位角、负阻尼相位角范围、低头力矩系数峰值及其相位角有规律地增大或减小。在不同来流状态下,翼型弯度、厚度和前缘半径的变化对DSV形成及其演化过程的影响规律不同。Dynamic stall significantly limits the flight performance of helicopters.To reveal the mechanism behind the variations in aerodynamic moments and damping characteristics under unsteady freestream,a numerical simulation method for the unsteady flow field around rotor airfoils is developed using the finite volume method,moving⁃embedded grid,Roe⁃MUSCL scheme,and S⁃A turbulence model.Based on this approach,numerical simulations are conducted on the unsteady aerodynamic characteristics of the SC1095 airfoil and its modified airfoils under steady/unsteady freestream and angle⁃of⁃attack conditions.Comparative analysis of the results shows that the formation and convection of the dynamic stall vortex(DSV)are the primary causes of moment stall.The trailing edge vortex(TEV)causing the DSV to lift off from the airfoil surface is the main factor contributing to the peak of the negative pitching moment coefficient.Within the scope of this paper,under steady freestream conditions,the airfoil exhibits leading⁃edge stall characteristics,while under unsteady freestream conditions,the stall pattern of the airfoil is influenced by its aerodynamic shape,leading to both leading⁃edge and trailing⁃edge stall behavior.The convective velocity and strength of DSV are significantly lower under unsteady freestream conditions compared to steady freestream conditions,although the differences in DSV convective velocity between airfoils of varying shapes are relatively small under both freestream conditions.Changes in airfoil camber,thickness,and leading⁃edge radius lead to regular increases or decreases in the phase angle of moment divergence,the range of negative damping phase angles,the peak value of nose⁃down moment coefficient,and its phase angle.The influence of changes in airfoil camber,thickness,and leading⁃edge radius on the formation and evolution of DSVs differs under steady and unsteady freestream conditions.

关 键 词：旋翼翼型 非定常来流 动态失速 俯仰力矩 气动阻尼 

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]