A new semi-empirical model with single blow measurements for exploring the heat transfer behavior in aluminum foam channels has been successfully developed. The results show that the local channel Nusselt number, Nu{sub}i or Nu{sub}b, initially increases from the channel inlet to some specific location and then gradually decreases along the streamwise direction for all the analytical cases. The location of the maximum Nu{sub}b appears at around X=0.7-0.8 for all the cases at any transient time. However, the location of maximum Nu{sub}i gradually shifts from the channel inlet to the downstream when time marches and finally approaches around X=0.3-O.4 at steady state. The local and average channel Nusselt numbers increase with increasing steady-state air preheating temperature ratio or Reynolds number, but decrease with increasing foam porosity. Additionally, the average channel Nusselt number initially increases with time marches and then gradually approaches constant values at steady state. Finally, all the ratios of (Nu{sup}b){sub}(ss)/(Nu{sub}b){sub}(ε=1) are much greater than unity This manifests that a significant heat transfer enhancement for the metallic foam channel compared with the hollow channel. A new correlation of (Nu{sub}b)/(Nu{sub}b){sub}(ε=1) in terms of Θ, Re, Da, γ and ε is proposed.
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