Effect of structure parameters on thermal performance of novel punched V-shape VGs for hear exchangers: An experimental approach

The use of perforated technology on the surface of the vortex generator (VG) has been proven to further enhance heat transfer performance by reducing its pressure loss. Based on this technology, a new type of turbulence insert is proposed in this work, which is composed of a V-shaped fixed ring with perforated rectangular VGs. The influence of its number (N = 2, 4, 6), VG area (S = 10, 20, 30 mm2), and pitch (P = 25, 50, 75 mm) on heat transfer and pressure drop under turbulent conditions was investigated through experiments. The results show that the influence of N and S on heat transfer intensity and pressure drop is consistent, but the value of P is inversely proportional to pressure drop and heat transfer intensity. Regardless of the influence of parameters on heat transfer intensity, it is explained by the field synergy number. Within the parameter range studied in this article, the optimal TEF value of 1.42 is attained when S=10mm2, N = 6, and Re=7454.