Interia effect in the squeeze film of a couple-stress fluid in biological bearings

Couple-stresses affect lubrication problem when additives are used or lubricant contains long-chain molecules. Such couple-stresses may have a considerable effect on the behaviour of bearings in practice. The influence of couple-stress and lubricant inertia on mechanical parameters of the curvilinear thrust bearing with squeeze film is considered. The simulation of the squeeze-film behaviour of a human joint modelled as a spherical bearing is discusses as an example. It is shown that the influence of couple-stresses on the characteristics of the discussed bearing is considerable but the inertia effect is significant and not negligible. Both the effects - couple-stress and inertia - provide an enhancement in the pressure distribution and in the load-carrying capacity.