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

SHE Bao-ying1， PENG Xu-dong1，2， MENG Xiang-kai1，2
（1. College of Mechanical Engineering， Zhejiang University of Technology， Hangzhou 310032， China；
2. The MOE Engineering Research Center of Process Equipment and Its Remanufacture， Zhejiang University of Technology， Hangzhou 310032， China）

Abstract： 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 [γ]，angle of inclination [β]=45°. The research has much important application value for theoretical research and engineering application of porous face seal.
Key words： hydrodynamic characteristics；JFO cavitation theory；directional dimples