The Combined Effects of Thermal and Acoustic Parameters on the Sound Absorption of Aluminum Foam Panels

- In a foamed panel, the sound absorption is influenced by several design parameters related mostly to acoustic features. This study has gathered the combined effects of thermo-acoustical parameters on sound absorption in aluminum foam panels. These parameters include pore size, porosity, relative density, flow resistivity, frequency, air temperature and pressure. The sound absorption coefficient has been calculated theoretically based on a reliable approach. The results have shown high absorption values for the aluminium foam (Al-foam) because of its low relative density. The values ranged from 0.75 for a relatively high-density panel and small pore size to 0.87 for a relatively low-density and medium pore-size board. Furthermore, the absorption values have decreased by increasing the temperature and pressure. The air temperature increase by 25 oC reduced the absorption by 2-4% at constant pressure. Specifically, the values of sound absorption coefficient at 10 bar and 100 oC were less by 10-15% compared to that obtained at standard atmospheric conditions.