Experimental Investigation of Heat Transfer and Pressure Drop in Square Metal Packed Duct with Different Boundary Heating


This paper presents experimental results of forced convection heat transfer and pressure drop across ( 12.5 * 12.5 * 100 cm ) square packed duct. The pad made of forty- eight metallic wrapping coil unit with (0.98 porosity ) and (26 W/m.°C thermal conductivity ). The local surface duct temperature and local heat transfer coefficientdistribution, Nusselt number, pressure drop and friction factor were measured for heat flux (0.56 to 2.73 kW/m2) ,Reynolds number (40339 to 54797 ) and three boundary condition of heat flux imposed on duct surface . It was found that Nusselt number increases as Reynold number, heat flux and number of duct surface exposed to heat flux increases. Nusselt number in packed duct is to be ( 1.2 , 1.19 ) times higher thanthe empty ducts at heating all surface and top & bottom surface of packed duct respectively. Many empirical relation between Reynold number, Nusselt number and pressure drop obtained in this study.