The lubrication film thickness developed between the two faces in a mechanical seal normally ranges in size from 1 to 15 μm.Therefore the influence of the surface tension of sealing medium cannot be ignored.In this paper a study of sealing ability of a laser-textured surface mechanical seal(LST-MS)with hydrophobic surface located at the inner radius was performed.The geometrical models of hydrophobic surface with nano-columns or nano-pores were presented

and their self-sealing ability was theoretically proved.The Reynolds equation for controlling film pressure between the two faces of such a LST-MS was solved by using the finite element method.The effects of surface tension coefficients of the sealing medium on film stiffness

opening force and leakage rate were studied at different rotational speeds and sealing pressures.It was proved theoretically that such a LST-MS could get zero-leakage under specific conditions.The results showed that when the LST-MS operated at the rotational speeds lower than 100 r·min-1 and low fluid pressure ratios lower than 2

film stiffness and opening force were kept high while leakage was substantially decreased.The film thickness fluctuation would take place due to external perturbation

but leakage would be controlled by using barrier fluids or flushing fluids with high surface tension coefficients.The width ratio of hydrophobic face to seal face was optimized in the range from 0.01 to 0.10.