Pressure-viscosity response in the inlet zone for quantitative elastohydrodynamics

The descriptions employed in classical elastohydrodynamic lubrication (EHL) of the piezoviscous effect at low pressures characteristic of the inlet zone are simply inaccurate for low viscosity liquids. This article offers the 1952 McEwen equation for accurately describing the pressure-viscosity effect at low inlet pressures for those liquids with sufficiently high inflection pressure that the faster-than-exponential response does not significantly affect the viscosity in the inlet. The parameters of this model have significance for the classical EHL film thickness formulas and these parameters are listed for several low viscosity liquids including a refrigerant.