In order to investigate phase change effect of liquid film on sealing performance of spiral groove liquid film seals

phase change model of non-contacting liquid film seals was established on the basis of mass conservation and mass source from Hertz equation. By discretization of governing equations with finite volume method

the effect of liquid film phase change on sealing performance was analyzed. Results show that phase change on sealing performance is closely related to sealing effectiveness. Both groove position and phase distribution in dynamic pressure groove have significant influence on sealing performance and pressure distribution at end face. During phase change in liquid film

seal opening force was increased but leakage was decreased for downstream pump seal

whereas the effect was different for upstream pumping seal. If the slot was close to inner diameter

seal opening force of upstream pumping seal was first increased and then decreased

but leakage was first decreased and then increased and finally decreased. If the slot was close to outer diameter

seal opening force of upstream pumping seal was increased linearly but leakage was first decreased and then increased. Phase transition occurred in groove region could strongly weaken hydrodynamic effects and largely impact on pressure distribution at the end face.