PERISTALTIC TRANSPORT OF A COUPLE STRESS FLUID: SOME APPLICATIONS TO HEMODYNAMICS

The paper deals with a theoretical investigation of the peristaltic transport of a couple stress fluid in a porous channel. The study is motivated toward investigating the physiological flow of blood in the micro-circulatory system, by taking account of the particle size effect. The velocity, pressure gradient, stream function, and frictional force of blood are investigated, when the Reynolds number is small and the wavelength is large, by using appropriate analytical and numerical methods. Effects of different physical parameters reflecting porosity, Darcy number, couple stress parameter, as well as amplitude ratio on velocity profiles, pumping action and frictional force, streamlines pattern, and trapping of blood are studied with particular emphasis. The computational results are presented in graphical form. The results are found to be in good agreement with those reported by Shapiro et al.(52) that was carried out for a nonporous channel without consideration of couple stress effect. The present study puts forward an important observation that for peristaltic transport of a couple stress fluid during free pumping, flow reversal can be considerably controlled by suitably adjusting the couple stress effect of the fluid/Darcy permeability of the channel. It is also possible to avoid the occurrence of trapping, by reducing the permeability.