Heat Transfer Performance of Aluminum Foams

Because of their interesting heat transfer and mechanical properties, metal foams have been proposed for several different applications, thermal and structural. This paper aims at pointing out the effective thermal fluid dynamic behavior of these new enhanced surfaces, which present high heat transfer area per unit of volume at the expense of high pressure drop. The paper presents the experimental heat transfer and pressure drop measurements relative to air flowing in forced convection through four different aluminum foams, when electrically heated. The tested aluminum foams present 5, 10, 20 and 40 PPI (pores per inch), porosity around 0.92–0.93, and 0.02 m of foam core height. The experimental heat transfer coefficients and pressure drops have been obtained by varying the air mass flow rate and the electrical power, which has been set at 25.0 kW m2, 32.5 kW m2, and 40.0 kW m2. The results have been compared against those measured for 40 mm high samples, in order to study the effects of the foam core height on the heat transfer. Moreover, predictions from two recent models are compared with heat transfer coefficient and pressure drop experimental data. The predictions are in good agreement with experimental data.