Mechanism of a wavy-tilt-dam mechanical seal under different working conditions

A three-dimensional thermal-elastic-hydrodynamic model of a wavy-tilt-dam mechanical seal is configured to study seal mechanisms under different working conditions, especially quasi-start-up and steady-state conditions. Results show that these mechanisms are different during speed-up and pressure-up. In speed-up, seal performance indicates both hydrostatic and hydrodynamic mechanisms are active because cavitation occurs; during pressure-up, only the hydrostatic mechanism is employed. Under steady-state conditions, even though no cavitation occurs, thermal-elastic deformations increase because the surface waviness of the seal affects the pressure and temperature distributions. Ultimately, this increases the thickness of the balance film. An experimental rig of the seal was built to verify results.