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跨音速颤振试验通常在稳定的理想流场中进行,不考虑实际非稳定流场的气动扰流对颤振特性的影响。在飞机T型尾翼跨音速颤振试验中,通过设置一种气动扰流装置对风洞流场实施干扰以研究气动扰流对飞机T型尾翼跨音速颤振特性的影响。试验结果表明,气动扰流可以将飞机T型尾翼的颤振耦合模态从平尾弯扭耦合型改变为垂尾弯扭耦合型;可显著降低飞机T型尾翼的颤振动压,翼面外气动扰流较翼面内气动扰流对飞机T尾颤振特性的影响作用大。其原因在于施加的气动扰流所诱导产生的跨音速激波作用在垂尾翼面上改变了垂尾的非定常气动力,引起气动刚度和气动阻尼发生改变,由于平尾的气动阻尼相对较大,可以预计,一旦气动扰流引起垂尾的气动阻尼迅速减小到其临界颤振阻尼,则会引起垂尾弯扭耦合颤振型先于平尾弯扭耦合颤振型发生,从而表现出T尾颤振动压的降低。在颤振模型风洞试验中,当风洞试验结果与期望不一致时,需要研究气动扰流的影响。
The transonic flutter test is usually performed in a steady and ideal flow field, irrespective of the effect of aerodynamic turbulence on the flutter characteristics of the actual unsteady flow field. In the transonic flutter test of the T-tail of the aircraft, a wind spoiler is provided to disturb the wind tunnel flow field to study the effect of aerodynamic spoiler on the transonic flutter characteristics of the T-tail. The experimental results show that the aerodynamic turbulence can change the flutter coupling mode of the T-tail of the aircraft from the horizontal tail-bend-torsional coupling type to the vertical tail-torsional-torsional coupling type, which can significantly reduce the flutter dynamic pressure and the aerodynamic The effects of aerodynamic disturbances on the tail flutter characteristics of aircraft T are more significant than those of the aerodynamic disturbances in the airfoil. The reason is that the transonic shock induced by the applied pneumatic spoiler changes the unsteady aerodynamic force of the tail at the vertical tail plane, causing the aerodynamic stiffness and aerodynamic damping to change. Due to the relatively large aerodynamic damping of the tail, It can be predicted that once the pneumatic spoiler causes vertical tail aerodynamic damping to decrease rapidly to its critical flutter damping, it will cause the vertical tail bending and torsion coupling flutter to occur before the tail-tail bending and torsional coupling flutter, Chatter vibration pressure reduction. In the flutter model wind tunnel test, when the wind tunnel test results are inconsistent with the expected results, it is necessary to study the influence of the pneumatic spoiler.