Turbulent forced convective heat transfer inside a locally heated tube. Numerical analysis considering heat conduction within the tube wall

A numerical analysis is carried out for turbulent forced convective heat transfer to water flowing inside a fouled tube of aluminum-brass or titanium, which is locally heated with uniform heat flux density from the outer tube surface. The results of the axial and radial distributions of temperature and the axial distributions of heat flux density at the fouling-fluid interface are shown graphically. Heat flow within the tube wall in the upstream and downstream direction is remarkable, especially in the case of a thick tube wall, short heated length, high thermal conductivity of the tube material, and heavy fouling. In these cases a simple relationship between the Nusselt number and Reynolds number cannot be obtained. An analysis for no tube wall thickness and no fouling is also made, and the Nu-Re relationship with a parameter of heated length to inner tube diameter is presented.