Mixed lubrication analysis of scrolls lubricated with CO2/oil mixture based on a homogeneous model

The tribological performance of scrolls lubricated with CO2/oil mixture is investigated using a combination of the mixed lubrication model and homogeneous model. The physical characteristics of the CO2/oil mixture were established prior to using the lubrication model. Then the evolution of the lubrication condition during the meshing process of scrolls was investigated, and the impact of radial clearance and refrigerant on the tribological behavior was assessed. The lubrication condition of the tribo-pair deteriorates as the meshing point moves toward the center of the scrolls. The effects of radial clearance and refrigerant mass fraction on friction and lubrication are strongly influenced by the meshing position. In addition, the presence of refrigerant leads to less hydrodynamic pressure and more asperity contact.