机翼跨音速风洞颤振试验模型的计算分析

Numerical analysis of flutter test model of a wing in a transonic wind tunnel

以某民机机翼跨音速颤振模型为研究对象,采用N-S方程求解固定边界流场的气动力,简化的跨音速小扰动方程求解运动边界流场的气动力,结合结构动力学的模态分析结果进行颤振特性分析。模型风洞试验前完成所有计算工作,试验后通过比较表明,计算结果与试验结果吻合:(1)颤振频率一致;(2)颤振速度随马赫数的变化趋势一致;(3)跨音速凹坑的底部位置一致;(4)颤振速度的偏差最大不超过10%,且在马赫数0.60和0.70处,偏差<1%。由此可见该计算方法的计算精度高,可用于风洞试验结果的预判,提升风洞试验结果的可信度和风洞试验的效率,也可作为民机适航符合性验证的一种手段。

A transonic flutter model of a civil plane wing was investigated. The aerodynamic force in a flow field with fixed boundary was solved with N-S equations. The aerodynamic force in a flow field with moving boundary was solved with the simplified transonic small disturbance equations. The flutter characteristics were studied by combining the modal analysis results of structural dynamics and the aerodynamic force. The numerical simulations of flutter were finished before the model wind tunnel tests. Ater tests, the comparisons showed that the numerical results agree well with the test data; the calculated flutter frequencies are close to the those of test data; the flutter speed varies with Mach number, the flutter speed of the former and that of the latter have the same trend; the bottom positions of transonic pits measured and calculated agree well; the flutter speed difference between simulation and test is less than 10% , and less than 1% w h e n Mach number is 0. 60 or 0. 70 ; the numerical method has a high accuracy, it can be used to predict wind tunnel tests, results,and improve the reliability and the efficiency of wind tunnel tests ; the method can also be a means of the compliance verification of civil aviation air worthness.