Numerical Investigations of the Convective Heat Transfer from Turbulent Flow Over Staggered Tube Bank

Abstract

The present work aims to introduce 2-D numerical investigations of turbulent flow over staggered tube bank by using a commercial CFD package (ANSYS-Fluent). The realizable k-e turbulent model is applied. The effect of the longitudinal pitch ratio (SL/D), transverse pitch ratio (ST/D), Reynolds number, and tube shape on the heat transfer and flow characteristics is studied. Due to symmetry, half of the tube bank rows are considered. The present simulation results are compared with the available experimental data and previous analytical results, which show acceptable agreement. The results of circular tube bank show that there is an enhancement on the heat transfer ranging from 1.02 to 8.8% when the longitudinal pitch ratio changed from 1.25 to 3 at ST/D = 1.25 and 5000 ≤ Re ≤ 50,000. Additionally, the friction factor decreases for ST/D ≥ 2 as the longitudinal pitch ratio increases but it increases for ST/D ≤ 1.5. For flat tube bank, the results show that as the length ratio decreases the heat transfer increases. Moreover, the flat tube diameter should be small to obtain the highest heat transfer. Furthermore, two different correlations are obtained for Nusselt number for the two tube banks.