Acoustic Absorption Behaviour of the Compound Aluminum-Alleged Foam in Low Frequencies

Metal foams, especially open-celled foams, have been greatly improved in the acoustic performance in high frequencies. In this paper, the acoustic absorption behaviour of the compound Al-alleged foam in low frequencies was studied. The compound Al-alleged foam is composed of two Al foam plates and an air-gap which between the two Al foam plates. The absorption coefficient of the foam at low frequencies was measured in different conditions by means of standing wave tube and the acoustic absorption regularity of the foam was studied.