Abstract
Sound propagation in one-dimensional piston-cavity systems is controlled using Active Compressional Damping Treatments (ACDT). The treatments rely in their operation on a classical Den Hartog damper system whose dynamics are controlled in response to the sound pressure level inside the cavity. The interactions between the piston, acoustic cavity and the controller are modeled using the classical impedance approach as well as the finite element method. The developed models are used to predict and compare the sound pressure fields developed inside the cavity for pistons with and without the ACDT treatments. Comparisons are also made when the pistons are treated with conventional Passive Compressional Damping Treatments (PCDT) which are ACDT operating in their open-loop mode. The obtained results suggest the effectiveness of the ACDT concept in attenuating the sound propagation inside cavities and its potential in controlling the sound pressure fields inside three-dimensional cavities.