Numerical study of the effect of hole arrangement on thermal efficiency of a pipe containing perforated porous media

Abstract

In this study, fluid flow and heat transfer in a round tube containing perforated porous media are investigated numerically. The flow is laminar and the tube is exposed to a constant heat flux in the wall. Numerical simulation is performed in three dimensions with finite volume method. The number of holes is considered to be between 5 and 9, one of which is located in the center and the other near the inner surface of the pipe wall and around the central hole. The fluid transport in porous region is modeled using the Darcy–Brinkman–Forcheimer model and the fluid–solid thermal energy exchange is simulated by means of the local thermal equilibrium model. Effects of various parameters affecting the heat transfer and pressure drop in perforated porous medium such as number of holes, distance between holes, volume of holes, Darcy number, porosity, and thermal conductivity have been discussed. Based on the results, the arrangement and the number of holes as well as the characteristics of porous media greatly affects the heat transfer and pressure drop. Under the same conditions, for example, a certain amount of porous material and a certain number of holes, the efficiency of the porous medium, i.e. higher heat transfer and lower pressure drop, can be significantly increased by proper arrangement of the holes. For the conditions used in this study, the Nusselt number can be increased by more than four times the value of the empty tube from the porous medium.