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传统的颤振试飞主要通过计算多个不同飞行状态下的阻尼比,外推出颤振临界速度,该方法存在一定的风险。为此,发展了一种基于亚临界响应的高安全性颤振边界预测方法。该方法利用三维弹性机翼在气流中的一个亚临界响应,解算出作用在机翼上的非定常模态气动力系数。通过系统辨识获得与动压无关的非定常气动力模型,进一步通过流固耦合分析求解颤振临界特性。并以AGARD 445.6机翼的颤振边界预测为例,在仿真环境中验证了该方法的可行性。在此基础上,进一步研究了一个固定马赫数下响应测试动压与颤振临界动压的比值对预测精度的影响。
The traditional flutter test flight mainly through the calculation of the damping ratio under different flight conditions, extrapolation of flutter critical speed, the method there is a certain risk. Therefore, a high-safety flutter boundary prediction method based on subcritical response has been developed. The method solves the unsteady modal aerodynamic coefficient acting on the wing by using a subcritical response of the three-dimensional elastic wing in the airflow. The unsteady aerodynamic model which has nothing to do with the dynamic pressure was obtained by system identification, and then the critical flutter characteristics were solved by fluid-solid coupling analysis. Taking the prediction of flutter boundary of AGARD 445.6 wing as an example, the feasibility of this method is verified in the simulation environment. Based on this, the influence of the ratio of dynamic pressure to flutter critical dynamic pressure on the prediction accuracy under a fixed Mach number is further studied.