Similarity Solution of Combined Convection Heat Transfer From a Rotating Cone or Disk to Non-Newtonian Fluids

Abstract

A powerful similarity solution of the highly nonlinear, coupled boundary-layer equations has been developed for steady laminar mixed convection heat transfer between a rotating cone/disk and power-law fluids. Of special interest are the effects of the power-law viscosity index, a generalized local Prandtl number, the buoyancy parameter, and the type of thermal wall condition on the velocity and temperature fields and hence the skin friction coefficient and the local Nusselt number. While the momentum boundary-layer thickness increases measurably with decreasing viscosity index n, the thermal boundary-layer thickness is less affected by changes in n. The magnitude and direction of the buoyancy force influence the upward velocity profile near the wall and the temperature profiles significantly. Both Prandtl number and buoyancy parameter have a more pronounced effect on the skin friction group, SFG ~ cf, than on the heat transfer group, HTG ~ Nu.