Analytical coupled vibroacoustic modeling of a duct-membrane-cavity system with uniform mean flow

Sound propagation in a duct becomes more complicated especially in the presence of flow and flexible structure, in which the vibro-acoustic and areo-acoustic coupling should be taken into account simultaneously. In this paper, a unified energy formulation for the structuralacoustic coupling analysis of a duct-mounted membrane backed by cavity with grazing flow is proposed. Sufficiently smooth admissible field functions are constructed using a modified Fourier series expansion. All the vibro-acoustic information can be obtained in conjunction with the generalized Lighthill equation and Rayleigh-Ritz procedure. Numerical results are then presented to validate the proposed model through the comparison with those given in current literature. Based on the model established, influence of various factors, including flow velocity, tensile force, as well as boundary restraints, on the vibro-acoustic coupling characteristics of such duct-membrane-cavity system are investigated and addressed.