Experiments on unsteady vortex flowfield of typical rotor airfoils under dynamic stall conditions

作     者：Wang Qing Zhao Qijun 

作者机构：National Key Laboratory of Science and Technology on Rotorcraft Aeromechanics Nanjing University of Aeronautics and Astronautics 

出 版 物：《Chinese Journal of Aeronautics》 (中国航空学报（英文版）)

年 卷 期：2016年第29卷第2期

页      面：358-374页

核心收录：

学科分类：080103[工学-流体力学] 08[工学] 080104[工学-工程力学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Natural Science Foundation of China(No.11272150) 

主　　题：Convection velocity Dynamic stall Leading edge vortex PIV Rotor airfoil 

摘      要：A new experiment for airfoil dynamic stall is conducted by employing the advanced par- ticle image velocimetry （PIV） technology in an open-return wind tunnel. The aim of this experimen- tal investigation is to demonstrate the influences of different motion parameters on the convection velocity, position and strength of leading edge vortex （LEV） of airfoil under different dynamic stall conditions. Two different typical rotor airfoils, OA209 and SC1095, are measured at different free stream velocities, oscillation frequencies, and angles of attack. It is demonstrated by the measured data that the airfoil with larger leading edge radius could notably decrease the strength of LEV. The angle of attack （AoA） of airfoil can obviously influence the dynamic stall characteristics of airfoil, and the LEV would be effectively inhibited by decreasing the mean pitch angle. In addition, the con- vection velocity of LEV is estimated in this measurement, and the results demonstrate that the influ- ence of airfoil shape on convection velocity of LEV is limited, but the convection velocity of LEV would be increased by enlarging the oscillation frequency. Meanwhile, the convection velocity of LEV is a time variant value, and this value would increase as the LEV convects to the trailing edge of airfoil.