篦齿封严结构气弹稳定性数值分析

Numerical analysis for aeroelastic stability of labyrinth seals

针对航空发动机中篦齿封严装置的气弹稳定性问题,用所发展的气弹稳定性分析的能量法,考查了两种不同的篦齿封严结构模型的颤振特性,对比分析了在不同节径振动下的气动功分布和模态气动阻尼比。结果表明:能量法可以用于预测篦齿封严结构的气弹稳定性,通过数值计算给出了改进前后篦齿封严结构低阶振动模态的气动功和模态气动阻尼比,改进后的篦齿结构在2节径振型下不再发生颤振,说明改进后的结构比改进前的气弹稳定性更好。

Labyrinth seal in aero engines may be prone to aeroelastic instabilities.Based on the energy method of the aeroelastic stability analysis from the rotor blades,the flutter characteristic of two different models of labyrinth seal was calculated to compare the unsteady aerodynamic force and modal aerodynamic damping ratio under different vibration nodal diameters.Analysis showed that the energy method can be used to predict aeroelastic stability of labyrinth seal model and provide a reference for aero engine seal disk structure design.The aerodynamic work and modal aerodynamic damping ratio of low order vibration mode of labyrinth seal model before and after improvement were given by numerical calculation;the model at 2 nodal diameter vibration mode no longer fluttered after improvement,showing that the aerodynamic stability of model after improvement was better than that before improvement.