The spreading of power-law fluids

Abstract

A thin-film formulation for the capillary-driven spreading of a power-law fluid is analysed to clarify, in particular, the relationship between macroscopic and microscopic contact angles and the dynamics of spreading in the completely-wetting case. The Newtonian fluid emerges as a critical case within the one-parameter family of evolution equations (characterized by the power-law exponent) and our analysis of the whole family sheds some new light on this special case, as well as on the spreading behaviour of shear-thinning and shear-thickening fluids. © 2001 Kluwer Academic Publishers.