Intensification of convective heat transfer in new shaped wavy channel configurations

The paper presents the specific wavy heat exchange surfaces in order to intensify convective heat transfer in the channel. The study is focused on the analysis of local and average heat transfer coefficients and Nusselt numbers by experimental method of the holographic interferometry and numerical simulations. The results are presented for temperatures of the heat exchange surfaces T-s = 318.15 K, 328.15 K, 338.15 K, and 348.15 K, Reynolds numbers Re = 1386-4203, and height between the surfaces H = 30, 35, 40, 45, and 50 mm. New correlating equations for average Nusselt number for the in-line and the offset wavy channels are determined. The total heat transfer and pressure drop j/f and thermal performance eta are calculated for the wavy channels compared with the smooth one. It is observed that the offset wavy channel achieves a higher j/f values compared with the in-line wavy channel for all H and T-s values. The thermal performance eta increases with Re and decreases with height H. The offset wavy channel achieves higher thermal performance eta by 5.7%-15.7% when changing Re and H compared with the in-line one.