Masoud Darbandi
Department of Aerospace Engineering, Sharif University of Technology, Azadi Ave, Tehran, 14588-89694, Iran
Mohammad-Saleh Abdollahpour
Sharif University of Technology, Azadi Ave, Tehran, 11365-11155, Iran
Kazem Mashayekh
Sharif University of Technology, Azadi Ave, Tehran, 14588-89694, Iran
Gerry E. Schneider
University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada
Heat exchangers are commonly used in different industries considering various working conditions. Nowadays, large amounts of research are conducted to increase their thermofluid performances due to optimum energy transfer argument. The tube-type heat exchanger performances depend highly on the thermofluid behavior of fluid passing through the bundled tubes. One advanced and effective idea to increase the thermofluid performance of flow passing through tubes is to extend their surfaces benefiting from dimples distributed all
over them. The main idea behind tube dimpling is to increase the heat transfer rate by local turbulence eddy generations. This would consequently enhance the overall heat transfer rate of corresponding heat exchangers. The heat exchanger designers need suitable correlations for the flow passing through dimpled tubes to ensure the accuracy of their designs. Normally, accurate correlations are produced via experiments. Alternatively, this study presents a robust numerical strategy to produce accurate correlations for both smooth and dimpled tubes. The Reynolds number range is from 2,500 to 80,000 and the Prandtl number from 0.7 to 70. The derived correlations are suitably evaluated against the experimental data. The comparison approves the high accuracy of derived correlations and the utilized methodology. The correlations indicate that the dimples can readily increase the Nusselt number of smooth tubes by about 127%, which really promotes the use of dimpled tubes in high-tech compact heat exchangers.