EFFECT OF BAFFLES GEOMETRY ON HEAT TRANSFER ENHANCEMENT INSIDE CORRUGATED DUCT

The turbulent heat transfer and friction inside a corrugated square duct inserted with various baffles geometries have been studied experimentally. Five types of baffles (flat, rectangular, semicircular, triangular and trapezoidal) are attached on top and bottom walls of the duct. The effects of duct wavy surface, baffle geometry, baffle position and flow Reynolds number are examined. Air is used as the working fluid with Reynolds number ranged from 3442.6 to 17213.19 under constant wall heat flux. Experimental results show obtained for average Nusselt numbers and friction factor. The results indicate that the trapezoidal baffled geometry provides a higher thermal performance than the other type baffled one. The present work showed that the highest thermal performance factor under the same pumping power obtained from the experiments, is about 2.26 times more than that of plain duct. Also, it is found that the thermal performance of the baffles attach on the bottom wall of the duct is higher than the other baffles attach on the top.