Effects of wall conduction on heat transfer for turbulent flow in a circular tube

In predicting convective heat transfer for turbulent flow inside a circular tube, the thermal boundary condition at the solid-fluid interface is usually assumed to be known. However, in reality, the thermal boundary condition is normally specified at the outside surface of the tube. The temperature and heat transfer coefficient at the interface are not known a priori. An analytical procedure is used here to obtain the interfacial temperature and the local Nusselt number for turbulent flow with axial and radial wall conduction taken into account. Wall conduction effects are examined by varying four important parameters; the Reynolds number, the Prandtl number, the ratio of thermal conductivity of solid wall to that of fluid, and the nondimensional thickness of the tube wall. Numerical results are obtained to determine their influence on heat transfer.