【Title】Sound transmission of an active acoustic structure with porous materials based on the (u,p) formulation

【Author】 HU Ying~1 CHEN Ke’an~2 M.A.Galland~3 C.Batifol~3 (1 Shanghai Aircraft Design and Research Institute, Shanghai 200232)(2 College of Marine, Northwestern Polytechnical University Xi’an 710072)(3 Centre Acoustique, LMFA, Ecole Centrale de Lyon Lyon 69134 France)

【Abstract】 A method based on the combination of the (u.p) formulation and finite element method was applied to calculating the acoustical performance of a double-wall active acoustic structure with porous materials. The (u,p) formulation based on the displacement in solid phase and the pressure in fluid phase was developed to investigate the sound propagation in porous materials. The acoustic performance of the double-wall active acoustic structure having porous materials was calculated and the measurement was taken. The numerical results matched well with the measured data. More than 10 dB transmission loss of the double-wall active acoustic structure can be improved in the resonance frequency with active control, and its absorption coefficient is up to 0.6 over 500 Hz. The relative error between the prediction and measurement is less than 5% at the resonance frequency of the porous materials.