直通型迷宫密封动力学特性研究

Study on the Dynamic Characteristics of the Straight-Through Labyrinth Seal

本文利用Fluent软件数值仿真研究了不同工况(进口预旋、转速和压比)下,偏心率分别为5%和10%、转子涡动速度为10%~240%倍转速的涡动转子–密封流场,获得了作用在涡动转子上的径向气流力和切向气流力,进而分析该气流力对转子振动的影响。研究结果表明:进口预旋速度对密封径向气流力影响不大,而对密封切向气流力影响很大。高转速下密封切向气流力在转子高频涡动下会变为正值,促进转子涡动,可能引起转子失稳。压比越高,密封气流力越大。密封径向气流力随着转子偏心率的增大而增大,但增大速率逐渐减缓。

This paper uses Fluent software numerical simulation to study the vortex rotor-seal flow field with eccentricity of 5% and 10% and rotor whirl speed of 10% - 240% under different working conditions (imported pre-spin, speed and pressure ratio), obtain the radial air force and tangential air force acting on the vortex rotor, and then analyze the effect of the air force on the rotor vibration. The research results show that the inlet pre-rotation speed has little effect on the radial air force of the seal, but has a great influence on the tangential air force of the seal. The sealing tangential airflow force at high speed will become positive under the high-frequency turbulence of the rotor, which promotes the vortex of the rotor and may cause the instability of the rotor. The higher the pressure ratio, the greater the sealing air force. The radial air flow force of the seal increases with the increase of the rotor eccentricity, but the increase rate gradually slows down.