Numerical Analysis of Wooden Porous Media Effects on Heat Transfer From a Staggered Tube Bundle

摘要

A numerical analysis of forced convective heat transfer from a staggered tube bundle with various low conductivity wooden porous media inserts at maximum Reynolds numbers 100 and 300, Prandtl number 0.7, and Darcy number 0.25 is presented. The tubes are at constant temperature. The extended Darcy-Brinkman-Forchheimer equations and corresponding energy equation are solved numerically using finite volume approach. Parametric studies are done for the analysis of porous medium thermal conductivity and Reynolds number on the local Nusselt number distribution. Three different porous media with various solid to fluid thermal conductivity ratios 2.5, 5, and 7.5 are used in the numerical analysis. The results are compared with the numerical data for tube bundles without porous media insert and show that the presence of wooden porous media can increase the heat transfer from a tube bundle significantly (more than 50% in some cases). It is shown that high conductivity porous media are more effective than the others for the heat transfer enhancement from a staggered tube bundle. However, the presence of a porous medium increases the pressure drop. Therefore, careful attention is needed for the selection of a porous material with good heat transfer characteristics and acceptable pressure drop.