Abstract: The directionality of surface dimples can guide the direction of fluid flow in the seal gap and produce fluid cumulative effect in the dimple length direction, which leads to obvious hydrodynamic effect. As a result, the seal faces separate and full film lubrication is formed. The textured mechanical face seals with different dimple shapes, such as circle, diamond, ellipse and rectangle were studied. Based on the mass-conserving JFO cavitation algorithm, a mathematical model was presented by taking the cavitation of liquid fluid between the two seal faces into consideration. The Reynolds equation was solved by use of the finite difference method, and pressure distribution was obtained. Comparative analysis of mechanical face seal performance with different dimple shapes at different operating parameters and geometric parameters was presented. The results showed that inclined dimple displayed better hydrodynamic effect than circle dimple under low speed or high pressure condition. The rectangle dimple showed the best hydrodynamic effect, and the diamond dimple had a lower leakage. Excellent hydrodynamic effect could be obtained for inclined dimple with different shapes when film thickness h₀=1.5-2.5 mm, pore depth h_p=2-3 mm, axial ratio γ=3-4, opponent texturing proportion β=0.5, inclination angle α₁=30°-50° and α₂=120°-140°.

Key words: surface, inclined dimples, hydrodynamic effect, cavitation, algorithm, mathematical modeling, seal performance

摘要： 表面微孔的方向性可以改变密封间隙中流体的流向，在孔区末端汇聚产生明显的流体动压效应，使摩擦副端面打开，形成全膜润滑。以不同开孔形状（圆形、菱形、椭圆形、长方形）型孔端面密封为研究对象，考虑润滑液膜中的空化现象，基于质量守恒JFO空化算法建立数值模拟模型，采用有限差分法求解Reynolds控制方程，获得端面膜压分布。对比分析了在不同操作参数和几何结构参数下不同开孔端面密封性能。结果表明：相比于圆孔，在低速或高压下，方向性型孔都具有较好的动压效应，且长方形孔的动压开启力最好，菱形孔泄漏率较小。当膜厚h₀=1.5～2.5 mm，孔深h_p=2～3 mm，长短轴比γ=3～4，反向开孔比β=0.5，倾斜角α₁=30°～50°、α₂=120°～140°时，不同形状方向性型孔可获得最佳的动压密封性能。

关键词: 表面, 方向性型孔, 动压效应, 空化, 算法, 数值模拟, 密封性能