Second Law Analysis of Heat Transfer in Taylor Couette Flow for Pseudoplastic Fluid

The Taylor Couette flow of pseudoplastic fluids is examined while dissipation due to viscous effects through the energy balance. The viscosity of fluid is simultaneously dependent on shear rate and temperature. Exponential dependence of viscosity on temperature is modeled through Nahme law and the shear dependency is modeled according to the Carreau equation. Hydrodynamically, stick boundary conditions are applied and thermally, both constant temperature and constant heat flux on the exterior of cylinders are considered. The governing motion and energy balance equations are coupled adding complexity to the already highly correlated set of differential equations. Introduction of Nahme number has resulted in a nonlinear base flow between the cylinders. As well, the condition of constant heat flux has moved the point of maximum temperature towards the inner cylinder. Taking viscous heating into account, the effects of parameters such as Nahme Number, Deborah Number, material time and pseudoplasticity constant on the heat transfer of the flow are investigated by second law analysis. Moreover, the study shows that the total entropy generation number decreases as the fluid elasticity increases. It, however, increases with increasing Nahme Number.