Experimental Study for Thermal –Hydraulic Performance of Semi-Circular Duct With Inserts

Abstract

This paper presents a study of heat transfer enhancement and pressure drop in a semi-circular duct for different geometric shape namely:flat , corrugated and dimple plate.A three ducts are  fitted withtwo types of perforated baffles ( rectangular baffles with  open area ratio of 28 %andsemi-circularbaffles with  open area ratio of 16.6 %). The tested duct has a constant wall heat flux condition. The experiments are carried out under varying airflow rate in terms of Reynolds number ranging from 3826 to 18750. The experimental data of heat transfer and pressure drop of the duct fitted with perforated baffles are compared with those of the plain duct under similar condition. The (Nu/Nu_o) value is obtained for dimple semi-circular duct withsemi-circular baffles(DS) which is  found to be about 1.98 - 4 time over the flat plain duct and 1.8 - 3.8,1.7-3.5, 1.6 -3,1.57-2.7, 1.47-2.5, 1.26-2, 1.1-1.6forCS, DR, FS ,CR FR, D and C respectively time over the flat plain duct and the higher thermal enhancement factor is found to be 3 for dimple duct with semi-circularperforated baffles(DS).