Extending the Applications of the Diffusion Equation Model with a Modified Boundary Condition in Sound Field Modeling

摘要

A modified boundary condition for a diffusion equation model was proposed [Y. Jing and N. Xiang, J. Acoust. Soc. Am., 124, 2008, pp.145-153] to better predict the sound field in spaces. This new boundary condition is able to consider the high absorption coefficient 1.0, and is based on a specular reflection boundary condition. This paper presents experimental verification of the boundary condition for the diffusion equation model when it is employed to predict the steady-state sound field in two different types of spaces: an urban square and a fitted room. In the first case, the absorption coefficient 1.0 is considered for the open top of the urban square, while in the second case, specular reflections on the room surfaces were found to be dominant [A. M. Ondet, and J. L. Barbry, J. Acoust. Soc. Am., 85, 1989, pp.787-796]. In both scenarios, good agreements between experimental results and numerical results have been found. This paper provides evidences that the diffusion equation model with the new boundary condition can be used in a wide range of types of spaces.