Three-dimensional numerical analysis of fin-and-oval tube heat exchanger with longitudinal vortex generators

In this paper, 3-D numerical simulations for air-side performance of fin-and-oval tube heat exchanger with longitudinal vortex generators (LVG) and fin-and-tube heat exchanger were performed. The results show that compared with fin-and-tube heat exchanger, under the calculated air inlet velocity range, the heat transfer performance (Nu) of fin-and-oval tube heat exchanger with longitudinal vortex generators are enhanced by 32.4%. The total heat transfer performance (Nu/f) of fin-and-oval tube heat exchanger with longitudinal vortex generators achieves enhancement up to 28.93%. It is found that the performance of fin-and-oval tube heat exchanger with longitudinal vortex generators is far better than that of the fin-and-tube heat exchanger. The basic heat transfer enhancement mechanism of longitudinal vortex could be explained from the view point of field synergy principle, which says that the reduction of the intersection angle between velocity and fluid temperature gradient is the basic reason for enhancing convective heat transfer.