A series of experiments were conducted to investigate the heat transfer which occurs with a heated, constant heat flux, horizontal, single circular cylinder is exposed to a vertical aiding flow of air with and without water spray....[ Read more ]

A series of experiments were conducted to investigate the heat transfer which occurs with a heated, constant heat flux, horizontal, single circular cylinder is exposed to a vertical aiding flow of air with and without water spray.

An open loop wind tunnel was constructed to provide a vertical water-in-air fluid stream. 25.4mm diameter test cylinder with maximum power of 1180W placed in the air stream. Three groups of 8 thermocouples separated 10mm apart were placed in the center of the longitudinal surface of the cylinder. The 8 thermocouples were placed evenly at 45° apart along the circumference of the cylinder. Experimental values of the average Nusselt number of the cylinder were obtained for the range of Reynolds number of air from 500 to 2000, and the range of volumetric water flow was determined as 2.210x10^-6 m³/s, 4.340x10^-6 m³/s and 8.496x10^-6 m³/s.

The experimental results of present study from the heat transfer from a single horizontal circular cylinder with and without air flow match well with the correlations proposed by pervious researches. Heat transfer of water spray on the horizontal heated circular cylinder with and without air flowing was then studied. The results show that the addition of water spray greatly increases the heat transfer from a cylinder surface to an air stream. Volumetric water flow rate improves the heat transfer significantly but no significant change in the heat transfer with different water temperature. And finally, simple modifications on the existing correlations of convective heat transfer are used to represent the experimental data collected in this study.