In this study, numerical simulations have been performed to investigate the influence of rectangular winglets as Vortex generators for enhancement of thermo-fluid performance in a fin-and-tube type heat exchanger having five staggered rows of tubes. The influence of placement of winglets over different pair of tubes, attack angles of the winglet pair, and their location has been examined under laminar flow conditions for Re ranging 400–1500. For the present analysis rectangular winglet pairs having “common-flow-up” orientation were employed for vortex generation. The effect of placement of different number of rectangular winglet pairs (1–5) has been investigated and the maximum enhancement in thermo-fluid performance was obtained as 27.4% compared to the baseline model (without winglet model). The winglets attack angle (5°, 10°, 15°, 20°, and 25°) were also investigated for best thermo-fluid performance and the optimum attack angle resulted in enhancement up to 33% over the baseline model. The optimum stream-wise and span-wise locations were identified which resulted in enhancement up to 29% and 25%, respectively, over the baseline model. Correlations for the prediction of Nusselt number, friction factor, and enhancement factor have been developed for stream-wise distance, span-wise distance, and attack angle of the winglets.
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