螺旋槽对自适应迷宫密封的影响研究

Influence of Spiral Groove on the Performance of Adaptive Labyrinth Seal

为了增强浮动迷宫密封的浮起性能和适应转子径向跳动的能力,在主轴跑道的外表面增加了槽型结构,通过试验测量和CFD数值仿真研究不同压差、转速下不同开槽方式(无槽、直线槽与螺旋槽)对浮动迷宫密封泄漏特性和浮起性能的影响。结果表明:泄漏量随着压差的增大近似呈线性增长,直线槽浮动迷宫与螺旋槽浮动迷宫泄漏量数值计算值最大分别增加了16.1%和18.7%,试验值最大增加分别为14.5%和15.1%;直线槽与螺旋槽对浮动迷宫密封浮起力的影响相差不大,但是随着压差的逐渐增加,螺旋槽对浮起力的影响相较于直线槽而言会越来越大;随着转速的增加,3种密封结构的泄漏量和浮起力变化很小,而且直线槽与螺旋槽密封结构泄漏量和浮起力都大于无槽密封结构。

In order to enhance the buoyancy performance of the floating labyrinth seal and its adaptability to the radial runout of the rotor,a groove was designed on the runway of the main shaft.The experimental equipment and CFD numerical analysis model of the floating labyrinth seal were established.The effects of different grooving modes(non-groove,straight groove and spiral groove)on the leakage characteristics and buoyancy performance of the floating labyrinth seal under pressure difference and rotational speed were studied.Results show that with the increase of pressure differential,the leakage approximate linearly increases,the numerical calculation values of leakage of the straight groove floating labyrinth and spiral groove floating labyrinth is increased by 16.1%and 18.7%in maximum,respectively,and the test values is increased by 14.5%and 15.1%in maximum,respectively.There is little difference between the influence of straight groove and spiral groove on the buoyancy of floating labyrinth seal,however,with the gradual increase of differential pressure,the influence of spiral groove on buoyancy will will be greater and greater than that of straight groove.With the increase of rotating speed,the leakage and buoyancy of the three sealing structures change little,and the leakage and buoyancy of the straight groove and spiral groove sealing structures are greater than that of the non-groove sealing structure.