where the equivalent fluid viscosity is ηn ¼m ∂u=∂z n1. m is the consistency coefficient and n is the power law exponent. The conditions of n41; n¼1 and no1 represents the dilatant fluid, Newtonian fluid, and pseudoplastic fluid behavior respectively. The 1-D Reynolds equation for a smooth surface lubricated with power law fluid in a simplified form is given by