Heat transfer characteristics of Taylor vortex flow with shear-thinning fluids

This study numerically investigates the heat transfer characteristics, including the fluid flow, of a Taylor vortex flow system with shear-thinning fluids. Governing equations were solved using OpenFOAM (R) 4.0 code. The Carreau model was utilized as the rheological model. The parameter (n) in the Carreau model, which describes the slope of a decrease in viscosity with an increase in shear-rate, was varied from 1 to 0.3. The local Nusselt number (Nu(L)) decreased with the increase in shear-thinning property. Furthermore, a correlation equation between the effective Reynolds number (Re-eff) and a global Nusselt number (Nu(G)) was proposed. Using this equation, Nu(G) was evaluated within a +/- 10% error in the case of n =1, 0.7, 0.5, and within a +/- 20% error in the case of n = 0.3. The size of the Taylor vortices became axially larger with an increase in the shear-thinning property. Furthermore, the thickness of the boundary layer of velocity and temperature increased with an increase in shear-thinning property. The ratio of the thickness of velocity boundary layer to the temperature boundary layer monotonically decreased with an increase in Re-eff . (C) 2018 Elsevier Ltd. All rights reserved.