Experimental Investigation on Turbulent Heat Transfer, Nusselt Number and Friction Factor Characteristics of Square Ducts

This paper presents the results of an experimental investigation of heat transfer to the airflow in the square duct. The main purpose of this study is influence of square ducts on the convective heat transfer mechanism. Under this investigation friction factor and the Nusselt Number were calculated. The reason that square ducts increase the fluid flow turbulence near the wall and also increase the heat transfer area. The results of the heat transfer are characterized in terms of the non-dimensional parameters: Nusselt number (Nu), Reynolds number (Re), and Prandtl number(Pr). The experimental measurements are carried out for Reynolds number range of10,000-50000.The heat transfer, friction factor and the pressure drop characteristics of turbulent flow of air (10,000 < Re < 50,000) through square ducts have been studied experimentally. The study shows significant improvements can be achieved with the square duct particularly in high prandtl number.