Numerical analysis to predict the optimum configuration of fin and tube heat exchanger with rectangular vortex generators for enhanced thermohydraulic performance

Abstract

The current numerical study has explored the effect of incorporation of rectangular winglets with circular, flat and oval tubes on the performance of compact heat exchangers. Rectangular winglet pairs are mounted behind the tubes at a span angle of 5° to obtain the enhanced performance. The obtained results show that fin and oval tube heat exchanger (FOTHE) having rectangular winglet pairs (RWPs) provides the higher thermal-hydraulic performance compared to the other configurations, on the basis of area goodness factor (j/f) and heat transfer rate per unit fan power consumption (Q/Pf). MOORA method also incorporated to obtain the performance ranking of the considered configurations of compact heat exchangers. The optimal configuration i.e. finned tube heat exchanger having oval tubes with rectangular winglet pairs, provides an increment of 13.84% and 9.99% in the heat transfer coefficient of air (h) at Re = 400 and Re = 900 respectively, compared to the baseline case. Moreover, an appreciable reduction of 26.61% and 29.79% in the pressure drop (∆p), compared to the baseline case, is obtained at Re = 400 and Re = 900 respectively.