Efficient Model for Acoustic Attenuators using the Method of Fundamental Solutions

In this work, the three-dimensional formulation of the Method of Fundamental Solutions (MFS) is applied to model acoustic problems in the frequency domain. This formulation is developed by making use of adequate Green’s function defined by the image-source technique, reducing the discretization necessary for the definition of the numerical model. The proposed approach is applied to study the sound attenuation provided by an acoustic attenuating device, consisting of a closed acoustic space located between inlet and outlet tubes. Absorbent properties of the lining materials of the acoustic device, defined using laboratory measurements of their absorption coefficients, are incorporated into the model. The proposed model is verified against reference numerical models based on a boundary integral equation formulation. An experimental validation is also performed, demonstrating that the model adequately simulates the sound propagation under experimental conditions. Numerical applications are then presented to demonstrate the behaviour of the system under different conditions.