A numerical study of convection in a channel with porous baffles

Abstract

The effects on heat transfer in a two-dimensional parallel plate channel with sixteen porous baffles in a staggered arrangement with a uniform heat flux heating applied to the top and bottom walls has been numerically investigated. Developing Flow (DF) was considered for this study. The Brinkman-Forchheimer-extended Darcy model was used for modeling the heat transfer and fluid flow through the porous baffles. The flow was assumed to be laminar. A finite volume based method in conjunction with the SIMPLEC algorithm was used to solve the model equations. Calculations were made by varying several independent parameters such as Reynolds number (Re), Darcy number ⎞ (Da), thermal conductivity ratio ⎛⎜ k e kf ⎠⎟ , baffle thickness ( * ) , non-dimensional w ⎝ baffle spacing ( * ) , and non-dimensional baffle height ( * ) . w The results of the study established that porous baffles out perform solid baffles from a pressure drop point of view. However, porous baffles under perform solid baffles from a heat transfer point of view. The ratio representing increase in heat transfer per unit increase in pumping power (heat transfer performance ratio) was found to be less than unity for all cases. Increasing the Darcy number was found to produce less desirable heat transfer enhancement ratios. Increasing the non-dimensional baffle spacing (d/w) and the baffle aspect ratio (H/w) were found to enhance heat transfer.