For an axisymmetric, steady-state, and fully-developed flow of an incompressible, constant-property fluid in a circular pipe, when viscous dissipation is important, show that the thermal energy...

For an axisymmetric, steady-state, and fully-developed flow of an incompressible, constant-property fluid in a circular pipe, when viscous dissipation is important, show that the thermal energy equation becomes

Now consider a long and fully insulated pipe, with an inlet temperature of T_in. Derive an expression for the temperature profile far away from the pipe where the flow is thermally developed.