机翼跨音速颤振特性的频域分析

从气动力影响系数矩阵的物理意义出发,推导出以气动力时域计算为基础的跨音速气动力影响系数矩阵的计算公式.通过求解非定常Euler方程,获得机翼简谐振动下的跨音速气动力时间历程,应用最小二乘法对模态气动力系数的时间历程进行曲线拟合,得到跨音速气动力影响系数矩阵,进而在频域内进行机翼的跨音速颤振特性分析.采用该方法计算了AGRAD 445.6机翼随马赫数变化的颤振边界,所得结果与文献的实验结果吻合良好,验证了该方法的可行性和准确性.

Frequency domain analysis for wing transonic flutter

In the time domain aerodynamics calculation, a new approach for flow field boundary controlling is suggested in the present study, in which the wing was forced to oscillate harmonically under small amplitude. The transonic aerodynamic force was computed by solving unsteady Euler equations, and then modal aerodynamic force was calculated using modal matrix. The least square method is used to fit the modal aerodynamic force coefficient time history. From the physical meaning of aerodynamic influence coefficient （AIC） matrix, the formulation of AIC matrix are derived according to time domain solution of modal aerodynamic force. Based on the transonic AIC matrix, wing transonic flutter characteristics can be obtained by frequency domain flutter solution. The transonic flutter charac- teristics of AGARD 445.6 wing are studied and the flutter boundary under different Mach numbers was presented. The results obtained by the present method are in good agreement with those obtained by experimental data of literatures.