Paper presented at the 8th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Mauritius, 11-13 July, 2011.
Due to constraints and changes in operating conditions, heat
exchangers are often forced to operate under conditions of
transitional flow. However, the heat transfer and flow
behavior in this regime is relatively unknown. By
describing the transitional characteristics it would be
possible to design heat exchangers to operate under these
conditions and improve the efficiency of the system. This
study was aimed at obtaining experimental data for water
flowing through a smooth tube with an inner diameter of
8 mm under constant heat flux conditions. Four heat flux
test cases were considered namely: 1 409, 3 354, 5 009 and
6 881 W/m2. The experiments covered a Reynolds number
range of 500 to 8 800, a Prandtl number range of 4 to 7, a
Nusselt number range of 6 to 67, and a Grashof number
range of 750 to 25 600. Experiments have shown a smooth
transition from laminar to turbulent flow.
