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.