High pressure rhelology of lubricants and limitations of the reynolds equation

摘要

A review of high pressure rheology hleads to the conclusion that the results from rheometers may be used to generate empirical rate equations which are useful in modelling EHD traction. However, an analytical treatment of piezo-viscous liquids reveals that the Reynolds equation adequately captures the mechanics of the piezo-viscous liquid only when the shear stress in much less than the reciprocal of the pressure viscosity coefficient. Otherwise the cross film pressure gradient cannot be neglected and secondary flows result.