前飞状态可变弯度翼型/旋翼气动特性  

Aerodynamic characteristics of variable-camber airfoil/rotor in forward flight

作　　者：张夏阳 高陈诚 招启军[1] 梁家辉 Xiayang ZHANG;Chencheng GAO;Qijun ZHAO;Jiahui LIANG(National Key Laboratory of Helicopter Aeromechanics,Nanjing University of Aeronautics and 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：《航空学报》2024年第24期106-121,共16页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(12102186);国家重点实验室基金(61422202201);中国科协青年人才托举工程(2022QNRC001);江苏高校优势学科建设工程资助项目。

摘　　要：智能材料技术的发展使得翼型/旋翼连续变弯度技术能得以实现。为研究前飞状态连续变弯度翼型/旋翼技术对动态失速条件下强非定常气动特性的影响机理,建立了基于运动嵌套网格方法和URANS方程的旋翼流场求解方法,并通过RBF网格变形方法实现翼型/旋翼变弯度后的贴体网格重构;通过前飞状态NACA0012翼型动态失速、SA349/2旋翼和SMART后缘小翼的非定常气动特性对比分析,验证了变形网格技术和数值求解方法的有效性;通过与传统刚性后缘小翼进行对比,揭示了连续变弯度技术对于提高翼型平均升阻比的原理;捕获了可变弯度翼型/旋翼对动态失速特性的复杂影响,获得了变弯度运动频率、幅值和初相位对翼型非定常气动特性的影响机理,以及三维旋转桨叶不同方位角和剖面位置的非定常气动载荷变化特性。结果表明:通过协调分配变弯度运动频率能够实现对旋翼气动载荷的有效控制;即使在动态失速状态下,变弯度幅值增量与翼型/旋翼非定常气动力增量呈现出近似线性的关系;变弯度初相位需与旋翼周期变距操纵初相位保持一致以抑制桨叶剖面气动力系数的发散。上述规律表明连续变弯度技术在旋翼配平或减振控制方面具有潜在的应用价值。The development of smart materials has made it possible to achieve continuous variable-camber function of airfoil/rotor.To study the influence mechanism of continuous variable-camber airfoil/rotor on the strong unsteady aerodynamic characteristics during dynamic stall,a rotor flowfield simulation method is established based on the moving-embedded mesh method and URANS equation,and the body-fitted mesh of variable-camber airfoil/rotor is reconstructed by the RBF mesh deformation method.The effectiveness of the mesh method and the numerical simulation method is verified by comparing the unsteady aerodynamic characteristics of the NACA0012 airfoil,the SA349/2 rotor and the SMART rotor with trailing edge winglet.A comparison with the traditional rigid trailing edge winglet reveal the principle and advantage of continuous variable-camber technology for improving the average lift-to-drag ratio of airfoil.The complex effect of variable-camber airfoil/rotor on dynamic stall characteristics is captured,and the influences of motion frequency,amplitude and initial phase of the variable-camber on the unsteady aerodynamic characteristics of the airfoil,as well as the unsteady aerodynamic load variation characteristics of the three-dimensional rotating blade with different azimuth angles and blade sections,are fully considered.The results demonstrate that the continuous variable-camber technology can effectively control the aerodynamic performance of the rotor through collaborative allocation of variable-camber frequencies.An approximate linear relationship between the variable-camber amplitude and the unsteady aerodynamic increment of the airfoil/rotor is observed even under the condition of dynamic stall.The initial phase of variable-camber should be consistent with the cyclic pitch control of rotor to suppress the divergence of sectional aerodynamic coefficient.The above rules indicate that the continuous variable-camber technology has great potential in rotor trim or vibration reduction.

关 键 词：连续变弯度 网格变形方法 动态失速 变弯度参数 非定常气动特性 

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]