The effect of inlet flow baffles on heat transfer

Baffles enhance heat transfer by disturbing boundary layer and bulk flow, creating impingement cooling. and increasing heat transfer surface area, This stud-v was conducted to determine how a single baffle placed at the inlet of a rectangular channel affects heat transfer and friction characteristics. The baffle was mounted on the tipper inner surface of the channel, and the channel base was heated by constant heat flux. Two different clearance ratios (C/H= 0.6, 1) and four baffle inclination angles were used (30, 45, 60, and 90degrees). Reynolds number changed in the range of 7100-28500. It was found that the heat transfer and friction factor depend significantly on the baffle inclination angle, clearance ratio, and Reynolds number. The average Nusselt number and friction factor increased with the decreasing clearance ratio and the increasing baffle angle. The performance analysis by the equal friction factor criterion showed that the use of the inlet baffle is not thermodynamically advantageous on the basis of heat transfer enhancement. (C) 2003 Elsevier Science Ltd.