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.