The lubricant film is the key parameter responsible for protecting rolling element surfaces from intimate contact and the ensuing danger of catastrophic failure. Since the 1970s, it has been recognized that the non-Newtonian character of the fluid must be taken into account to accurately predict the lubricant film thickness. Of particular interest is the assessment of the performance of lubricants with polymer-enhanced additives. For this purpose, a constitutive equation developed by Carreau has emerged as a viable means for incorporating shear-thinning effects into elastohydrodynamic lubrication (EHL) calculations of film thickness.
Over a decade ago, Bair and Winer (1) introduced a correction-factor formula that one can apply to the Newtonian film thickness to account for the shear-thinning effect. Later, Bair (2) developed an improved correction-factor expression that took the slide-roll ratio into account. This correction factor was based on the EHL treatment of film thickness known as...
