毫米级不同形状方向性孔流体动压特性对比研究

Comparison of hydrodynamic characteristics of millimetre-sized directional dimples of different shapes

为提高多孔端面密封的流体动压特性,提出了毫米级多孔端面结构。针对密封端面间液膜空化现象问题,运用基于质量守恒的JFO空化理论建立了不同形状方向性孔(圆形、椭圆形、菱形)的理论分析模型,采用有限差分法求解了密封端面间流体膜压的Reynolds控制方程,获得了端面膜压分布图,从而在密封端面内外压差相等(即只考虑动压效应)的情况下对比分析了转速n、方向因子γ、倾斜角β等参数对毫米级不同形状方向性孔的流体动压特性的影响规律。研究结果表明:不同形状方向性孔的流体动压特性存在较大差别,方向因子γ越小、倾斜角β=0°的椭圆孔动压特性最佳,而方向因子γ越大、倾斜角β=45°的菱形孔的动压特性差。该研究方法对多孔端面密封理论和工程实践具有重要的应用价值。

In order to improve hydrodynamic characteristics of dimple, the millimeter scale dimples were therefore put forward.Taking into consideration the cavitation existed in liquid film, JFO cavitation theory was used to establish the theoretical analysis models of mechanical seal face with directional dimples of different shapes（circle,ellipse,diamond）. The finite difference method was applied to solve the seal face film pressure control fluid Reynolds equation, from which the film pressure distribution of mechanical seal face was obtained. Finally, the comparison analysis of influence law was conducted of different parameters such as the speed n , direction factor γ ,angle of inclination β acted on the hydrodynamic characteristics of millimetre-sized directional dimples of different shape.The results show that there are huge differences among the hydrodynamic characteristics between directional dimples of different shapes.The ellipse porous has the best performance with the smaller directional factor γ , angle of inclination β =0° Whereas the diamond porous has the worst characteristic with the higher directional factor β , angle of inclination β =45°. The research has much important application value for theoretical research and engineering application of porous face seal.