Heat transfer enhancement in rectangular narrow channel with longitudinal vortex generators

The heat transfer and fluid flow in a horizontal rectangular narrow channel with longitudinal vortex generators (LVGs) mounted on side-walls were studied experimentally. The effect of the form of mounting LVG on heat transfer and fluid flow performance was also investigated with Reynolds number ranging from 3000 to 20000. The LVGs were able to improve the Colburn factor j by 25%-55% at the expense of increased pressure drop. A comparison of thermal performance was made under three constraints (identical mass flow-IMF, identical pressure drop-IPD and identical pumping power-IPP). The heat transfer performance of the channel with different direction LVGs mounted on two sidewalls was better than that of other tested channels, and the heat transfer performance of parallel-flow was a little better than that of counter-flow.