Study of the Hydrodynamic Characteristics of Non-Newtonian Polymer Solution Fluid in Concentric Annulus Using Computational Fluid Dynamics Methods

Non-Newtonian fluids flowing in a concentric annulus have been widely observed in industrial chemical processes. In this study, the hydrodynamic characteristics of a non-Newtonian fluid (polymer solution) in concentric annulus are investigated using computational fluid dynamics (CFD) modeling and numerical simulation methods. First, a simple grid independence analysis is carried out to select appropriate grid parameters. Then the rationality of the proposed CFD model is confirmed by the near-wall velocity profiles. Based on the validated model, the effects of the fluid properties and radius ratio on the flow structure characteristics are studied at various inlet velocities. According to the simulated flow fields (i.e., velocity, pressure, strain rate, and wall shear stress), the flow pattern, flow resistance, and residence time distribution characteristics are analyzed in the laminar and turbulent regimes. The presented results show that non-Newtonian fluids have unique flow behaviors in concentric annulus when compared with Newtonian fluids.