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 semicircular
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/Nuo) value is obtained for dimple semicircular
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).