NUMERICAL-SIMULATION OF PSEUDOPLASTIC FLUID FLOW OVER A SQUARE CYLINDER USING ANSYS FLUENT

Flow of any non-Newtonian fluid past a bluff body requires considerable attention due to its involvement in chemical. polymer, and process engineering. In the current study, numerical simulation of the flow past a square cylinder was conducted at Reynolds number Re = 100 in a pseudoplastic fluid flow environment (0.1 <= n < 1.0, where n represents the power index of non-Newtonian fluid) using ANSYS Fluent. Instantaneous and time-averaged floro fields along with the flow parameters were calculated to understand the behavior of pseudoplastic flow in the presence of an obstacle (ie, the square cylinder), It was observed that the drag force value increased in the pseudoplastic fluid low compared to that in Newtonian fluid flow (n=1), whereas the vortex shedding frequency decreased as the n value decreased. Close to n = 0.4. clear evidence of flow instability was seen, which drastically changed the vortex shedding Mechanism and affected the flow downstream from the cylinder. In addition, at n=0.1 the fluid flow stood still downstream due to very high flow resistance-a common feature of flow fields with a very high pseudoplastic nature.