静子叶片角度对颤振影响数值仿真及试验研究

Numerical Simulation and Experimental Validation of the Influences of Stator Angle on Fan Blade Flutter

随着航空发动机推重比提高和气动负荷增加,叶片颤振问题屡见不鲜。以某跨声速风扇叶片为研究对象,基于移相能量法开展一级转子叶片颤振预测,分析了叶片在低换算转速下的颤振稳定性,绘制了理论预测的颤振边界。通过开展进口可调叶片(VIGV)角度变化对叶片一弯气动阻尼的影响规律研究,获取了VIGV角度变化对叶片的颤振稳定性的影响。通过多动态参数统一测量,在部件试验器上进行了试验验证。结果表明:叶片在低换算转速发生典型一弯失速颤振,振动应力与脉动压力均出现瞬时突增的特征;VIGV关角度可以有效提高叶片一弯气动阻尼,VIGV关3°时,气动阻尼可以提高20%;数值预测的颤振边界与试验结果吻合较好。

Flutter has become a common issue for fan blade with the increase of engine thrustweight ratio and aerodynamic load.The flutter predication and suppression of a transonic fan blade were investigated.The flutter boundary for low corrected speed was predicted based on phaseshifted energy method.The variation of aerodynamic damping for first bending mode with the VIGV angle was obtained.Then the effects of VIGV close were achieved.In addition,the multidynamic parameters system was utilized to validate the numerical simulations on a test rig.Results show that the investigated fan blade encountered typical flutter at first bend mode with the vibration stress and pressure showing sudden increase.VIGV close could effectively boost the aerodynamic damping within certain range,and hence,improve the blade flutter stability.The optimum VIGV closing angle for this case is 3°with a 20%rise in aerodynamic damping and the blade is predicted to be flutter free.The experimental results were in good accord with the simulation results.