Internal cooling augmentation in rectangular channel using two inclined baffles

Abstract

This experimental study investigates the local heat transfer characteristics and the associated frictional head loss in a rectangular channel with inclined solid and perforated baffles. A combination of two baffles of same overall size is used in this experiment. The upstream baffle is attached to the top heated surface, while the position, orientation, and the shape of the other baffle is varied to identify the optimum configuration for enhanced heat transfer. A constant surface heat flux is applied from the top surface, but the bottom and the side surfaces are maintained at an adiabatic condition. The flow Reynolds number for this experimental study is varied between 12,000 and 41,000. The inline placement of baffles augments the overall heat transfer significantly by combining both jet impingement and the boundary layer separation. Experimental results show that the local Nusselt number distribution is strongly depended on the position, orientation, and geometry of the second baffle plate. The friction factor ratio goes up with an increase in the Reynolds number, but its value depends on the arrangement of baffles. Like single inclined baffle and rib-mounted channels, the frictional head loss is much higher for two inclined baffles.