Heat transfer enhancements in heat exchangers fitted with porous media Part I: constant wall temperature

• Published in: International journal of thermal sciences Vol. 42; no. 4; pp. 385 - 395
• Main Author: Mohamad, A.A.
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.04.2003; Elsevier
• Subjects: Applied sciences; Devices using thermal energy; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Heat exchangers (included heat transformers, condensers, cooling towers); Flow(fluid); Pressure drop; Modeling; Heat exchanger; Heat transfer; Porous medium
• ISSN: 1290-0729; 1778-4166
• DOI: 10.1016/S1290-0729(02)00039-X

This work investigates heat transfer enhancement for a flow in a pipe or a channel fully or partially filled with porous medium. The porous layer inserted at the core of the conduit. Forced, laminar flow is assumed and the effects of porous layer thickness on the rate of heat transfer and pressure drop were investigated. The Darcy number (permeability) is varied in the range of 10 −6 to 10.0. Developing and fully developed flow conditions are considered in the analysis. It is found that the plug flow assumption is not valid for Da>10 −3. The effect of varying the inertia term (Forchheimer term) is also investigated and it is found that the inertia term is not that important for Da<10 −4 for the range of the parameters investigated. Partially filling the conduit with porous medium has two advantages: it enhances the rate of heat transfer, and the pressure drop is much less than that for a conduit fully filled with a porous medium.