密封齿对侧开槽对迷宫密封泄漏特性的影响

Effect of Slotting of Opposite Side of Sealing Tooth on Leakage Characteristics of Labyrinth Seals

为了降低迷宫密封的泄漏量,提出一种在直通型迷宫密封的密封齿前端和后端设立凹槽的密封结构,基于CFD方法,建立迷宫密封数值仿真模型。通过与已有试验数据的对比,验证模型的正确性。探讨不同湍流模型的适用范围,并对比光滑表面、前置凹槽、后置凹槽3种结构在泄漏量、轴向压降及流场速度分布的差异性。结果表明:SST湍流模型更加适用于迷宫密封这种窄间隙的近壁面流动;前置凹槽结构降低泄漏量的效果较差,只有在高压力差下才能降低泄漏量;后置凹槽结构能改变迷宫密封腔内漩涡方向及状态,进而降低迷宫密封透气效应,加剧密封的能量耗散的同时降低泄漏量。因此,后置凹槽的迷宫密封结构具有较好的工程应用前景。

In order to reduce the leakage of the labyrinth seal,a seal structure with a groove at the front end and the rear end of the seal tooth of the straight-through labyrinth seal was proposed.Based on the CFD method,a numerical simulation model of the labyrinth seal was established.The correctness of the model was verified by comparison with the existing experimental data.The applicable range of different turbulence models was discussed,and the differences in leakage,axial pressure drop and flow field velocity distribution of smooth surface,front groove and rear groove were compared.The results show that the SST turbulence model is more suitable for the near-wall flow of the narrow gap of the labyrinth seal.The front groove structure has a poor effect in reducing the leakage amount,and which can reduce the leakage amount only under the high pressure difference.The rear groove structure can change the direction and state of the vortex in the labyrinth seal cavity,thereby weakening the gas barrier effect of the labyrinth seal,increasing the energy dissipation of the seal and reducing the leakage amount.Therefore,the labyrinth seal structure of the rear groove has engineering application prospects.