Average Heat Transfer Coefficient for Transient Flow in Aluminum Foam-Filled Channels

Experimental research was performed on transient flow and heat transfer in a rectangular channel filled with aluminum foam metal, and key parameters such as foam pore size (porosity), fluid flow (velocity) were analyzed. In order to analyze the experimental data effectively, the average heat transfer coefficient was redefined and deduced. Furthermore, non-dimensional Darcy and Reynolds number based on the permeability were introduced. And the empirical equations describing convective heat transfer in Al foam-filled channel were finally obtained. Experimental results show that increasing flow rate can enhance convective heat transfer. The average heat transfer coefficient is relatively sensitive to the pore size. For low-porosity metal foam, permeability is the dominating factor on heat transfer. Under the condition of the same or approaching porosity, heat transfer can be enhanced by using metal foams of higher permeability and Darcy number; with the gain of a lower pressure drop.