Load carrying capacity and friction in starved hydrodynamically lubricated circular contacts

The current work studies the evolution of the load carrying capacity and friction forces as a function of the level of starvation for spherical hydrodynamically lubricated contacts. Unfortunately, the parabolic approximation of the geometry cannot be applied, as it leads to infinite friction forces for the fully flooded case. Thus, this work uses the complete spherical geometry but this introduces an additional parameter which is the ratio between the minimum film thickness h(0) and the radius R. Two viscous forces are distinguished: the Couette term associated with sliding and the Poiseuille term generated by the pressure gradient. The load and friction forces are computed numerically as a function of the geometry and the level of starvation. Finally, some simple curve fitted equations are given for load and friction as a function of the degree of starvation A and the ratio .