Transient response and rub-impact phenomenon of liquid lubricated non-contacting mechanical seals during external pressure fluctuation

The purpose of this paper is to investigate the dynamic contact behavior and transient response of liquid lubricated non-contacting mechanical seals during external pressure fluctuation. The presented model of spiral groove mechanical seals includes the Reynolds equation considering surface roughness and mass-conserving cavitation boundary, elastoplastic asperity contact model expressing rub-impact phenomenon, as well as the dynamic equation describing the vibrations of stator which were solved simultaneously with a numerical method. Results indicate that the vibration amplitude and frequency of sealing performances are affected significantly by the external pressure. The increment of rotational speed avoids face rub-contact and reduces the instantaneous variation of leakage. The results presented in the study are expected to provide a theoretical guidance to improve stability and safety of sealing system.