As one focal point for research and application of mechanical seals

leakage mechanism of seal interface involves characterizing leakage channels

modeling contact mechanics of rough surface

exploring morphological changes of seal interface and defining fluid flow resistance in leakage channels. The development of leakage channel models of contact mechanical seals in recent decades was reviewed. After analyzing contributions and problems of G-W

M-B

and Persson models of rough surface contact mechanics

a new percolation channel model was proposed. The effects of fractal parameters of seal interface

fluid flow resistance of channels

and limited size of seal interface on leakage characteristics were discussed. It was noteworthy to point out that leakage occurrence at seal interface was mainly due to pore connection across interface and low flow resistance of fluid through interface channels. Future studies on leakage mechanism will be formation of leakage channels and characteristics of fluid flow in these channels.