Peristaltic motion of generalized Newtonian fluid in a non-uniform channel

The problem of peristaltic transport of a non-Newtonian (Carreau) fluid in a non-uniform channel has been investigated under zero Reynolds number with long wavelength approximation. The problem is formulated using a perturbation expansion in terms of a variant of Weissenberg number. It is assumed that chyme in the male small intestine behave like Carreau fluid since most of the physiological fluid behave like a non-Newtonian fluid, Pressure rise and friction force, in the case of non-uniform geometry, are found much smaller than the corresponding values in the case of uniform geometry. Furthermore, the pressure rise and the friction force are smaller in the case of Carreau fluid than Newtonian fluid, A comparison between Carreau fluid, couple-stress fluid and Casson fluid is given. The pressure rise and friction force are discussed for various of the physical parameters of interest.