Study of hysteresis associated with power-law fluids past square prisms arranged in tandem

Abstract

Present numerical study attempts to investigate the hysteresis phenomena and different flow patterns of the power-law fluids past two unconfined square prisms arranged in tandem configuration. The convective heat transfer from the bodies is also studied. The gap spacing between the cylinders varies from 1d to 8d, where d is the length of each prism side. The simulations are performed for different power-law indexes (n=0.7,1and1.6)atRe=100,150(Pe=70,105). It is observed that the flow patterns of the power-law fluids depend on the gap spacing between prisms. When the gap spacing is varied from 1d to 8d, three major flow regimes (single slender body, reattach and co-shedding) are found for the selected power-law indexes at Re=100 and 150. Similar to the Newtonian fluid (n=1), the hysteresis with two different flow patterns is observed for shear-thinning (n<1) and shear-thickening (n>1) fluids in a certain range of the gap lengths, where the hysteresis limit depends on the fluids type and Reynolds number.