Analysis of laminar-flow heat transfer in the entrance region of circular tubes

Abstract Non-linear equations of laminar flow of a viscous incompressible fluid in the entrance region of a circular tube have been solved by an exact numerical method to obtain the velocity of the flow in this region. This velocity distribution is used in solving the energy equation numerically to obtain temperature profiles under constant wall temperature and also under constant heat flux at the wall. The local Nusselt number is calculated and the results are compared with those given by other workers.