Comparison of thermal-hidraulic performances of vortex generators mounted on heated plate: experimental study and flow visualization

Abstract

Improvement of heat transfer in fin and tube heat exchangers for improving energy efficiency is required to be performed. In the present study, an enhancement in the rate of heat transfer is done by manipulating fin geometry on the fin and tube using longitudinal vortex generators. Perforated concave delta winglet is introduced as the latest longitudinal vortex generator that can improve heat transfer better than previous vortex generators. Experimental study is conducted to investigate the thermal and hydraulic performance of perforated concave delta winglet vortex generators in a rectangular channel. From the results of the study, it is found that the heat transfer rate increases up to 78.9% of the baseline by using three pairs of concave delta winglet vortex generators with three holes. This value is 27.3% higher than using delta winglet vortex generator with three holes. However, this increase in heat transfer rate is also accompanied by an increase in pressure losses in the flow. Pressure drop increases up to five times from the baseline by installing three pairs of three-hole concave delta winglet vortex generators.