Thin-Film Flow of a Power-Law Fluid Down an Inclined Plane

An analysis is presented for two-dimensional flow of a thin layer of power-law fluid down an inclined plane. Integration of the equations of motion using lubrication approximations shows that for both pseudoplastic and dilatant fluids, the rate of advance of a blob of fluid of given volume decreases with increasing time. The analysis further reveals that for dimensionless time less than about 0.50, a blob of the fluid (of fixed volume) with given exponent n moves faster than a fluid of same volume with larger n. However, thereafter, a blob of the latter fluid moves faster than the former fluid.