液体密封端面倾斜椭圆孔上游泵送特性

气液异相介质隔离密封的实现有赖于密封端面几何型槽的上游泵送特性，为探索多孔端面实现液封气密封的设计途径，对液体密封端面倾斜椭圆孔上游泵送特性开展研究. 考虑空化效应，采用有限差分方法对转速、密封间隙、密封压力等操作参数和孔深、倾斜角、方向因子、孔数等结构参数对开启力和泄漏率的影响规律进行了数值分析. 结果显示:液体润滑条件下端面倾斜椭圆孔可产生明显的上游泵送效应，增加周向孔数和方向因子可实现被密封介质的完全零泄漏，同时可产生明显的流体动压效应使端面开启力提高50%以上. 文中密封压力条件下，孔深取5~10 μm，倾斜角取45°，周向孔数大于80，方向因子大于3时，密封可实现完全反向泵送，反向泄漏率的增加与随着孔数、方向因子和孔深的增加而增加. 

Upstream Pumping Characteristic of Inclined-Ellipse-Dimples on Liquid-Lubricated Seal Face

The realization of the gas-liquid heterogeneous medium isolation seal depends on the upstream pumping characteristics of the geometric groove of the sealing face. In order to explore the design approach of the liquid sealing gas seal for the porous face, the upstream pumping characteristic of inclined-ellipse-dimples on liquid seal face was theoretically analyzed. Considering the cavitation effect, the finite difference method was used to numerically analyze the influences of operating parameters (e.g. rotation speed, seal clearance and seal pressure) and the structural parameters (e.g. dimple depth, inclination angle, slender ratio and dimple number on the open force and leakage rate). Results show that the inclined-ellipse-dimple liquid face seals may present significant upstream pumping and hydrodynamic effects, which led to open force improved more than 50% greater in the analysis. A complete backward leakage may be achieved by the inclined-ellipse-dimple upstream pumping face seals by increasing dimple number and slender ratio. A complete backward leakage can be achieved under pressure condition in the cases of 5~10 μm dimple depth, 45° inclination angle, greater than 80 dimple number and greater than 3 slender ratio. Meanwhile, the increase in reverse leakage rate increased with the dimple number, slender ratio, and dimple depth.