The effect of variable properties on the helical flow and heat transfer of power law fluids

Laminar flow and forced convection heat transfer of the time independent non–Newtonian fluid obeying power law stress-strain relation have been investigated numerically in the annular space between two coaxial rotating cylinders. The problem is considered when the inner cylinder rotates about the common axis with constant angular velocity and the outer cylinder is at rest. The viscosity of the fluid and thermal conductivity are assumed to vary with the temperature. The outer surface of the annulus is considered to be adiabatic, while the inner surface has a uniform temperature. The tangential and axial momentum equations and energy equation have been solved iteratively by using a finite difference method. For the steady fully developed flow, the velocity distributions, temperature profiles, the volumetric flow rate, torque and the average Nusselt number have been obtained for different values of the radius ratio and model parameters.