Experimental investigation of heat transfer and pressure drop in serrated finned tube banks with staggered layouts

An experimental study was performed to investigate the heat transfer and pressure drop characteristics of serrated finned tube banks with staggered layouts. The influences of varied fin densities, transversal tube spacing and longitudinal tube spacing were presented. For a constant fin height, an increase in the fin density resulted in an increase in the Euler number, and a gradual decrease in the Nusselt number was observed as the Reynolds number increased. An increase in the transversal tube spacing corresponded to a significant reduction in the Euler number, whereas the Nusselt number essentially remained unchanged. The longitudinal tube spacing had an insignificant effect on the Nusselt and Euler numbers, and the optimum ratio of the transversal tube spacing to longitudinal tube spacing increased with an increase in the transversal tube spacing. Scaling of the tube spacing had little effect on the Nusselt number but had a significant influence on the Euler number. Finally, predictive correlations for Nusselt and Euler numbers were developed based on the data presented here, and comparisons between the test data from this paper and the predictive values from previously published correlations were performed.

► Tested the thermal–hydraulic characteristics of twelve serrated finned tube banks.
► Presented the effects of the fin density, transversal and longitudinal tube spacing.
► Advanced the correlations of Nusselt and Euler number based on the test data.
► Conducted a comprehensive comparison of the relative correlations in literatures.