直升机全机气动噪声特性风洞试验

Conducting research on the aeroacoustic characteristics of helicopters in a wind tunnel is an effective method for evaluating helicopter noise levels. Aeroacoustic tests were conducted on the full helicopter configuration, systematically investigating the noise characteristics of the complete aircraft and various component assembly configu rations. Firstly, to ensure the accuracy of the test results, the precision of the model control and ratio of the signal and noise were validated by comparing the test data from different wind tunnels at home and abroad. Secondly, by conducting aeroacoustic wind tunnel tests on main rotor/fuselage configurations, the impact of parameters such as advance ratio, thrust coefficient, collective pitch angle, and shaft tilt angle on noise spectrum characteristics, harmonic noise amplitude, and overall sound pressure level was analyzed. Finally, the contribution of the tail rotor to the aeroacoustic performance of the full configuration was also analyzed, followed by a parametric analysis of the dominant noise contributors. The research results indicate that in the hovering state and forward flight, the tail rotor increases mid-to-high-frequency noise. The shaft tilt angle significantly impacts noise characteristics across different configurations, and in forward flight, the thrust coefficient primarily affects low- and mid-frequency noise, whereas under descent flight condition, its influence shifts to mid-and high-frequency noise. The tail rotor enhances overall noise in hover and level forward flight. However, under descent flight conditions, its contribution becomes less pronounced due to the dominant noise generated by Blade-Vortex Interaction (BVI).