The sealing performance of rotating mechanical equipment has an important impact on the energy consumption

efficiency and environmental protection during the production process. Based on the percolation theory

the variation law of the porosity distribution of the contacting mechanical seal interface with fractal parameters concerning the surface topography of rotary and stationary rings as well as the normal contact pressure was also discussed. A single-layer lattice leakage channel structure model of sealing interface was also established. A single-layer lattice leakage model referring to the channel structure of sealing interface was established

and three different states (percolating state

critical percolating state and non-percolating state) can be acquired under different contact pressure. According to the liquid capillary force and gas Knudsen number

the fluid flow criterion in the micro-channel was proposed

and flow resistance and leakage flow through sealing interface were analyzed

moreover

leakage mechanism of contacting mechanical seal interface was also illustrated. The research results provide a theoretical basis for the optimal design and leakage control of contacting mechanical seals in the next work.