Towards the direct validation of computational lubrication modelling of hip replacements

This study attempted to provide insights into validating computational lubrication modelling of hip replacements. Direct comparisons between experimental measurements and numerical simulations were conducted for the central film thickness in a CoCr-on-glass hip bearing pair. A low-viscosity mineral oil and a 25% bovine serum were used as lubricants, respectively. Results indicated that for the low-viscosity lubricant case, the film thicknesses predicted by the computational model were comparable to the experimental measurements. For the bovine serum case, the computational results did not agree with those measured by experiments due to the viscosity model adopted in the computational models. A new effective viscosity equation was proposed to accurately predict the lubrication performance of hip replacements for protein-containing lubricants under transient conditions.