迎角对间隙舵面的非线性颤振特性影响研究

EFFECT OF ANGLE OF ATTACK ON FLUTTER CHARACTERISTICS OF A CONTROL SURFACE WITH FREE-PLAY NONLINEARITY

针对典型超音速舵面,采用基于CFD(computational fluid dynamic)技术的当地流活塞理论计算气动载荷,运用等效线化方法分析带有间隙非线性的舵面颤振特性。研究飞行迎角和舵面间隙大小对系统极限环颤振特性的影响规律。计算结果表明,适当赋予一定的气动预载荷、减小间隙大小等措施,可以提高带有间隙舵面的气动弹性稳定性。对于该舵面模型而言,无间隙颤振速度和舵面间隙大小满足国军标要求时,有间隙舵面在实际飞行中不会发生破坏性颤振,只在0°迎角情况下才会出现微幅极限环运动。

Limit cycle flutter of a 3D supersonic control surface with preload free-play is studied.CFD（computational fluid dynamics） based local piston theory is use to compute unsteady aerodynamic loads,and equivalent linearization method is use to analysis the limit cycle flutter of the control surface.The effects of angle of attack and free-play on the characteristic of the limit cycle flutter are studied.The results show that aerodynamic preloads and reduction of the free-play can improve the stability of the aeroelastic system.For this supersonic control surface,if the linear flutter speed and free-play of the rudder satisfies the national military standard,acute flutter won＇t appeal in the flight state,only small amplitude limit cycle oscillation will appeal at 0 angle attack flight.