Development and Testing of Hypersonic Flutter Test Capability

摘要

To investigate the hypersonic flutter behavior of wings and all-movable control surfaces, a hypersonic wind tunnel flutter test capability has been developed by the China Academy of Aerospace Aerodynamics. This Paper outlines the design of the hypersonic flutter test rig; demonstrates the utility of the rig and the flutter test technique for hypersonic flutter research; and assesses the repeatability of the hypersonic flutter test, the application of subcritical flutter boundary identification methods, the effect of the rate of increase of dynamic pressure on flutter, and the aerodynamic heating effect. Descriptions of the data acquisition system and the experimental procedure are presented. Four models with the same design were tested for flutter at Mach numbers of 4.95 and 5.95. A wavelet time frequency domain analysis method was employed to evaluate the trend of structural frequency coupling. The results showed good repeatability of the test. Both the flutter margin method and the damping ratio extrapolation method had high prediction accuracy in flutter boundary prediction. The rate of increase of dynamic pressure did not have any significant effect on the flutter boundary. However, a high rate of increase of dynamic pressure resulted in unsuccessful flutter prediction for the damping ratio extrapolation method. The leading edge and the windward side of the model were the parts subject to severe aerodynamic heating, but their temperatures were lower than the stagnation temperature of the airflow.