Dehumidification of Turbulent Air Flow over a Thick Fin: An Experimental Study

Abstract

An experimental study has been carried out to investigate the performance of a vertical rectangular fin of finite thickness and moderate size when dehumidification occurs in turbulent flow. Tests were conducted for various free-stream velocities and relative humidities for a blunt leading edged fin under both dry and wet conditions. Further tests were also devised for an attached elliptical leading edge. Lower dry and wet fin surface temperatures were recorded for an elliptical leading edge due to the absence of flow separation and reattachment. During dehumidification tests, water droplets of various sizes formed on the surface of the fin. On the basis of visual observation, for a clean surface, no film condensation occurred. Using the theoretical model reported in reference (1) and the measured fin surface temperatures, heat-transfer correlations in terms of Nusselt and Reynolds numbers were developed. These correlations allowed the effect of simultaneous heat and mass transfer to be estimated. Dry and wet fin efficiencies were also determined for both blunt and elliptical leading edges using the measured fin surface temperatures.