Research on dynamic wind tunnel test technology of rotor airfoil

It is urgent to establish and develop the dynamic wind tunnel test technology for rotor airfoil design optimization and performance determination. Through dynamic simulation and structural optimization design, based on the FL–11 low-speed wind tunnel, a two degree of freedom dynamic test device for rotor airfoil is developed. It can not only complete the single degree of freedom dynamic motion of pitch and plunge, but also realize the coupling operation of pitch/plunge, with the highest oscillation frequency of 5 Hz. Based on the FL–20 continuous transonic wind tunnel, a set of high-frequency and high-speed oscillation test device for rotor airfoil is developed, with the maximum pitch oscillation frequency exceeding 17 Hz and the maximum test Reynolds number exceeding 5 × 10⁶. The simulated parameter envelope meets the parameter requirements of the real helicopter. A large-scale rotor airfoil dynamic test device is developed based on the FL–14 low-speed wind tunnel, with the airfoil model chord length of 800 mm and the maximum test Reynolds number of 4 × 10⁶. The accurate measuring and testing technique of the rotor airfoil dynamic test is developed, and the verification test is carried out. The results show that the dynamic test data of the rotor airfoil are reasonable and reliable, which indicates that the test system and related test technology have high reliability. It can provide important technical support for the research of rotor airfoil dynamic stall.