Effects of Rectangular Wing Vortex Generators on the Thermal-Hydraulic Performance of Louvered Fin and Flat Tube Heat Exchanger

In this paper, a novel composite heat transfer enhancement technique comprised of louvered fins (LFs) and rectangular wing vortex generators (RWVGs) is proposed to improve the LF side thermal-hydraulic performance of louvered fin and flat tube heat exchangers (LFHEs). After validation of the LF side pressure drop Delta P and heat transfer coefficient h(LF) of the baseline by experiments, the numerical method is applied to investigate the influential mechanisms of the RWVG parameters (the number N (7 to 15), attack angle beta (30 degrees to 90 degrees), height H-VG (0.8 mm to 2 mm) and width W-VG (0.8 mm to 1.2 mm)) on the performance of the LFHE in the velocity range of 3 m/s to 10 m/s. Results show that thermal-hydraulic performance of the LFHE is significantly impacted by the RWVGs, and according to the performance evaluation criteria (PEC), the LFHE achieves its optimal thermal-hydraulic performance when N=7, beta=45 degrees, H-VG=1.8 mm and W-VG=1 mm. Compared to the baseline, the maximum, minimum and average increments of PEC for the optimal case are 13.85%, 4.67% and 8.39%, respectively.