Effect of axial conduction and viscous dissipation on heat transfer for laminar flow through a circular pipe

The effect of viscous dissipation and axial conduction on heat transfer for laminar forced convection flow through a circular pipe was studied. Constant wall temperature boundary condition was imposed on the circular pipe and the flow is assumed to be hydrodynamically developed and thermally developing. Numerical solutions were obtained to observe the variations of non-dimensional bulk mean temperature, Nusselt number and wall heat from (or) to the fluid for Brinkman numbers ±1.0, ±0.5, ±0.2, 0.0 and Peclet numbers 10, 50, 100, 300 and 500. It was found that the heat generated by viscous dissipation was higher for higher Brinkman number and it delays the thermal entrance development of the fluid. The effect of axial conduction becomes negligible when the value of Peclet number crosses hundred