高超声速风洞连续变动压舵面颤振试验

为了研究舵、翼面高超声速颤振特性，中国航天空气动力技术研究院建立了高超声速风洞连续变动压颤振试验技术。对具有相同结构动力学和气动特性的舵面模型进行颤振试验，试验马赫数为4.95和5.95。试验中缓慢连续增加试验动压直至颤振发生，并由此获得颤振临界参数；采用短时傅里叶变换时频域分析法研究了试验中模型频率随动压变化的耦合特性，分析表明该模型在试验条件下发生了经典弯扭耦合颤振。试验中还采用亚临界试验数据对颤振余度法和阻尼外推法2种颤振边界预测技术进行了研究，2种方法在高超声速颤振试验中都显示了良好的预测精度。研究还表明，动压增加的速率对颤振边界的预测精度影响较小。采用红外热成像技术对模型的气动加热进行了研究，温度场测量显示舵面最高温度出现在舵根部前缘位置，舵前缘和舵面斜面中后部温度也较高；舵轴裸露在流场中的部分由于反射板附面层的影响其气动加热问题并不严重。

Hypersonic wind tunnel flutter test research on rudder models by continuously varying dynamic pressure

In order to study the hypersonic flutter behavior of rudder models, a hypersonic wind tunnel flutter test technique by continuously varying dynamic pressure was developed and experimentally studied in China Academy of Aerospace Aerodynamics. The models with the same structural and aerodynamic design were tested at Mach number 4.95 and 5.95. The flutter critical parameters were obtained by slowly increasing the dynamic pressure until flutter onset. The short-time-fourier-transform time-frequency domain analysis method was used to study the frequency coupling characteristics. The analysis shows that it is the classic flutter that the bending and torsion mode couples as the dynamic pressure increases. Based on the structural dynamic parameter identification method, the damping ratio extrapolation method and the flutter margin method were used to predict the flutter critical parameters with the subcritical data. Both methods show a good prediction accuracy. The results also indicate that the rate of increase of dynamic pressure has small effect on the prediction of the flutter boundary. The temperature field measurements show that the maximum temperature of the model appears at the leading edge of the wing root. The temperatures of the leading edge and the rear part of the slope of the rudder are also relatively high. The temperature of the leading edge of the rudder shaft exposed to the flow field is not high, which might be due to the influence of the reflector surface boundary layer.