局部振动对火星环境下薄翼型气动性能的影响  

Effect of local oscillation on aerodynamics of thin airfoil in Mars environment

作　　者：陈肇麟 陆政旭 肖天航[1] 邓双厚[1] CHEN Zhaolin;LU Zhengxu;XIAO Tianhang;DENG Shuanghou(National Defense Key Laboratory of Aircraft Advanced Design Technology,College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学航空学院飞行器先进设计技术国防重点学科实验室,南京210016

出　　处：《北京航空航天大学学报》2023年第11期2938-2950,共13页Journal of Beijing University of Aeronautics and Astronautics

基　　金：国家自然科学基金(11672133,12002161);江苏高校优势学科建设工程。

摘　　要：火星的稀薄大气环境迫使无人机在亚临界雷诺数范围工作,低雷诺数层流分离问题给无人机气动性能带来极其不利的影响。同时,火星大气的声速较低,使无人机运行的马赫数更高,压缩效应增强并可能产生激波。为研究火星环境下翼型局部振动的流动控制作用,采用基于动网格的数值方法对非定常流场进行模拟。选取NACA5605低雷诺数薄翼型,雷诺数为1.5×10^(4),马赫数为0.43和0.63。时均流场和时均气动力系数结果显示:翼型局部振动能够明显减少时均分离区的大小,起到增升减阻的作用。非定常流场表明流动控制机理在于振动产生的涡流运动抑制了翼型尾缘附近的层流分离。研究了不同振幅、频率和振动位置下的流动控制效果。最佳参数下,马赫数为0.43时升阻比最多提高24.7%,马赫数为0.63时升阻比最多提高52%。The thin atmosphere of Mars constrains the MAV in the subcritical Reynolds number regime,where the laminar boundary layer separation extremely adversely affects the aerodynamic performance of UAVs.Meanwhile,the low sound velocity of the Martian atmosphere results in a higher Mach number of UAVs,which enhances the compression effect and may generate shock waves.The numerical approach based on the dynamic mesh is used to model the unsteady flow field and examine the flow control effect of the airfoil local oscillation with the atmospheric characteristics of Mars.The NACA5605 thin airfoil is selected,the Reynolds number is 1.5×10^(4),and the Mach number is 0.43 and 0.63.The airfoil local oscillation can greatly reduce the size of the separation zone,increasing lift and decreasing drag,according to the results of the time-averaged flow field and time-averaged aerodynamic coefficient.The unsteady flow field shows that the flow control mechanism is that the vortex motion generated by oscillation restrains the laminar flow separation near the trailing edge of the airfoil.The flow control efficiency under different amplitudes,frequencies,and oscillation locations is studied.Under the optimal parameters,the lift-to-drag ratio is improved up to 24.7%at 0.43 Mach number while 52%at 0.63 Mach number.

关 键 词：火星环境 低雷诺数 层流分离 局部振动 流动控制 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]