拟合曲线槽干气密封流场的数值模拟及分析

Numerical Simulation and Analysis of Flow Field for Dry Gas Seal with Fitted Curve Groove Based on Tracing Line

取螺旋槽中间面、中间线上的流体迹线进行拟合,将该拟合曲线作为干气密封的槽型线,建立拟合曲线槽三维立体模型,运用Fluent软件对拟合曲线槽干气密封在气膜厚度为3～5μm时3种工况(低压低速、中压中速、高压高速)下的压力、泄漏量和气膜推力进行数值模拟和分析,并与螺旋槽进行比较。结果表明:在低压低速下,拟合曲线槽和螺旋槽的动压效果都不明显,且泄漏量相差不大;在中压中速下,气膜厚度为3和4μm时拟合曲线槽的动压效果比螺旋槽的好,但2种槽的泄漏量相差不大;在高压高速下,气膜厚度为3μm时拟合曲线槽的动压效果比螺旋槽的好,并且泄漏量比螺旋槽的小;在3种工况下拟合曲线槽的气膜推力都比螺旋槽的大。

The fluid tracing line taken from spiral groove middle surface and middle line was fitted and used as the type line of dry gas seal groove, and a three-dimension model of fitted curve groove was established. Under three conditions of low pressure and low speed, middle pressure and middle speed, and high pressure and high speed, the pressure, leakage and gas film open force of fitted curve groove dry gas seal with film thickness of 3 - 5 μm were calculated by using Fluent software, and were analyzed and compared with those of spiral groove. The results show that under low pressure and low speed conditions ,the fitted curve groove and spiral groove have weak dynamic pressure effect, and have almost the same leakage. Under middle pressure and middle speed conditions, the dynamic pressure effects of fitted curve grooves with film thickness of 3 and 4μm are better than that of spiral grooves, but their leakages are still almost the same. Under high pressure and high speed conditions, the dynamic pressure effect of fitted ctirve groove with film thickness of 3 μm is better than that of spiral groove, and the leakage of fitted curve groove is smaller than that of spiral groove. The gas film open force of fitted curve groove is larger than that of spiral groove under three conditions.