Enhancement of heat transfer in a rectangular channel with perforated baffles

One problem in using baffles in the channels is the formation of Lower Heat Transfer Areas (LHTA), particularly in the downstream region of baffles (i.e. in baffle-wall corners). The present paper is an investigation of the performance of a new baffle design aiming to enhance the heat transfer phenomenon in the channel. It concerns a perforated baffle having a row of four holes placed at three different positions. These positions are characterized by a ratio called the PAR (Pores Axis Ratio). Three values are taken for the PAR and which are 0.190, 0.425 and 0.660, respectively. The characteristics of fluid flows and heat transfer are presented for Reynolds numbers ranging from 10(4) to 10(5). All investigations are achieved with the help of the CFD code Fluent Some numerical results are validated with available experimental data and a satisfactory agreement is found. The obtained results show that the Pores Axis Ratio (PAR) of 0.190 is the best design that eliminates significantly the LHTAs, giving thus an increase in the heat transfer rate from 2% to 65% compared with the simple baffle. (C) 2016 Elsevier Ltd. All rights reserved.