Peristaltic transport of a Herschel-Bulkley fluid in contact with a Newtonian fluid

Peristaltic transport of flerschel-Bulkley fluid in contact with a Newtonian fluid in a channel is investigated for its various applications to flows with physiological fluids (blood, chyme, intrauterine fluid, etc.). The primary application is when blood flows through small vessels; blood has a peripheral layer of plasma and a. core region of suspension of all the erythrocytes. Thai; is, in the modeling of blood flow, one needs to consider the core region consisting of a yield stress fluid and the peripheral region consisting of a Newtonian fluid. Peristaltic pumping of a yield stress fluid in contact with a Newtonian fluid has not previously been studied in detail. Our goal is to initiate such a study. The Herschel-Bulkley fluid model considered here reduces to the power law model in the absence of yield stress. The stream function, the velocity field, and the equation of the interface are obtained and discussed. When the yield stress tau(0) - \u3e 0 and when the index n = 1, our results agree with those of Brasseur et al. (J. Fluid Mech. 174 (1987), 495) for peristaltic transport of the Newtonian fluid. It is observed that for a given flux (Q) over bar the pressure rise Delta p increases with an increase in the amplitude ratio phi. Furthermore, the results obtained for the flow characteristics reveal many interesting behaviors that warrant further study of the peristaltic transport models with two immiscible physiological fluids