Numerical simulation of flow of shear-thinning fluids in corrugated channels

Abstract

A numerical study of flow of a shear thinning fluid through a pair of corrugated plates was carried out. The aim of the study was to observe and understand the behavior of the flow of shear thinning fluids through channels were the fluid is subjected to a periodic increase and decrease in cross-section area. Such conditions are frequently observed in the flow of blood through blood vessels, movement of lubricating oils through the ground during the oil extraction process, in the process industry. Since we are dealing with non-Newtonian fluids the non-linear terms in the constitutive equation have a significant affect on their behavior. The plates modeled for the study had a sinusoidal profile. A total of four different plates were with varying amplitude and wavelengths were simulated. The simulations were done both in two and three dimensional space. A wide range of Reynolds numbers were used for each plate. The Reynolds number used was a function of the half the average plate spacing (h) and the velocity. The range of Reynolds numbers used is 100 to 1000. The velocity profiles along the crest, trough and center lines were generated. It was observed that even at low velocities and low Reynolds numbers the shear stress at the wall was significant. It was also observed that even at low velocities and low Reynolds numbers reversed flow can occur near the regions where the profile of geometry is sinusoidal. Such behavior is a characteristic of shear thinning fluid.