Evaluation of Porous Materials Performance on Forced Heat Transfer: Current Conditions and Future Challenges

Expanded surfaces are considered as the common way to heat transfer increment in the industry, but due to their operating conditions and lack of footprint, their use in some situations is limited. Because of its ability in thermal efficiency increment using increasing available area and change in velocity gradient, the porous medium has been considered as a novel solution in heat transfer increment. During this investigation the effective parameters on heat transfer (Nusselt number (Nu)) in the presence of porous medium (configuration, thermal conductivity, pore gradient, porosity, permeability and Darcy number (Da), thickness, fluid velocity, and heat source) were studied. The studied configurations can be classified in partial and fully porous categories. Among the investigated papers, the fully filled configuration usually has shown the maximum exchanged energy and pressure drop. Because using a porous medium leads to pressure drop increase, an index was reported to compare between different configuration can be applied. Finally, limitations and challenges in this field were investigated.