AN ENERGY DIFFUSION MODEL FOR INTERIOR ACOUSTICS WITH STRUCTURAL COUPLING USING THE BOUNDARY ELEMENT METHOD

摘要

Recently, a new model for the propagation of sound inrninterior volumes known as the acoustic diffusion equation hasrnbeen explored as an alternative method for acoustic predictionsrnand analysis. The model uses statistical methods standard inrnhigh frequency room acoustics to compute a spatial distributionrnof acoustic energy over time as a diffusion process. For volumesrncoupled through a structural partition, the energy consumed byrnstructural vibration and acoustic energy transmitted betweenrnvolumes has been incorporated through a simple acousticrntransmission coefficient. In this paper, a Boundary ElementrnMethod (BEM) solution to the simple diffusion model isrndeveloped. The integral form of the 3D acoustic diffusionrnequation for coupled volumes is derived using the Laplacerntransform and Green’s Second Identity. The solution using thernBEM is developed as well as an efficient Laplace transformrninversion scheme to obtain both steady state and transientrninterior acoustic energy. In addition, a fully coupled modelrnwhere both structural and acoustic energy are computed as arndiffusion process is proposed. A simple volume configuration isrnexamined as the diffusion models are analyzed and compared tornconventional room acoustics analysis methods. Advantages ofrnthe energy diffusion methods over conventional methods, suchrnas computation of energy distributions and accuraterntransmission from one volume to another, are revealed as therncomparisons are made.