Abstract: In order to solve the problem of precision machining of the mechanical seal of the wave face, a step-convergent mechanical seal structure derived from the change of the wave degree seal is proposed, and its sealing performance is parametrically analyzed by CFD numerical simulation with consideration of liquid film cavitation effect. The results show that with the increase of trough depth, number of slots, slot opening, and sealing pressure, the bearing capacity and leakage of liquid film increase. With the increase of the speed, the bearing capacity increases and the leakage amount decreases; as the thickness of the film increases, the bearing capacity decreases, and the amount of leakage increases. Under the working conditions of small film thickness, high speed, and low sealing pressure, it is easier to produce liquid film cavitation and reduce fluid leakage. Smaller trough depth will enhance the shear of the fluid, the cavitation effect will be enhanced, and the leakage amount will be reduced, so as to achieve the purpose of reducing leakage.

Key words: mechanical seals, cavitation effect, sealing performance, reduce leakage