Hydrodynamic Lubrication with Wear and Asperity Contact in Mechanical Face Seals.

In this report a model is developed which describes lubrication effects caused by circumferential waviness in face seals. This two dimensional model accounts for the effects of hydrodynamic and hydrostatic pressure, fluid film cavitation, surface roughness, asperity contact and load support, and elastic deflection. The fraction of load supported by fluid pressure, relative wear rate, pressure distribution, friction, and leakage are predicted given the waviness, pressure, speed, material, geometry, viscosity, and surface roughness. The model is applicable to heavily loaded, low viscosity seals where partial contact is expected. The results from the model have been compared to available experimental results. The model shows that the magnitude of surface roughness is the most important parameter determining the extent of hydrodynamic lubrication. Seal faces with low roughness are more likely to display hydrodynamic effects than seal faces having larger roughness.