低滞后刷式密封泄漏特性与滞后效应研究

Investigation on Leakage Characteristics and Hysteresis Effect of Low Hysteresis Brush Seals

针对带遮流板的低滞后刷式密封结构,采用经试验数据修正的多孔介质模型,对3种减压腔轴向尺寸的结构在不同上下游压差下的三维泄漏流场进行了数值模拟,对这3种结构在压差上升和下降过程中呈现的泄漏系数滞后效应进行数值分析。研究结果表明:经试验修正的多孔介质模型能较好地预测低滞后刷式密封结构的泄漏量;不同减压腔轴向尺寸的低滞后刷式密封的压力分布趋势基本相同,减压腔使刷束和后挡板间几乎不存在压力梯度;随着压差的上升,泄漏系数先迅速增大后趋于定值;减压腔轴向尺寸为0.5 mm时泄漏系数最小,但其表现出的滞后效应更显著。研究结果可为低滞后刷式密封泄漏特性滞后效应研究及结构设计提供依据。

The three-dimensional leakage flow field of low-hysteresis brush seals with a flow deflector were numerically simulated with different axial length of pressure relief chamber at differential pressures drop using a porous medium model calibrated by experimental data.The hysteresis effect of the leakage coefficient was numerically analyzed with the three pressure relief chamber structures in the rising and falling process of pressure drop.The results show that the porous medium model calibrated by experimental data can better predict the leakage flow of the low-hysteresis brush seals.The pressure distribution of the low-hysteresis brush seals with different axial length of pressure relief chamber is nearly the same,and there is almost no pressure gradient between the brush pack and the backing plate because of the existence of pressure relief chamber.The leakage coefficient is increased rapidly with the increase of the pressure drop and then tends to be stable.When the axial length of pressure relief chamber is 0.5 mm,the leakage coefficient is the smallest,while the hysteres is effect is more significant.The research result can contribute to the study of leakage and hysteresis effect and structural design for low-hysteresis brush seals.