Room Acoustics Modelling

过去几十年的循环试验令人信服地表明，没有充分考虑声音衍射和散射的常见几何建模方案不能可靠地预测封闭空间中的声场。作为一种充分考虑声音的物理性质即波动特性的建模工具，TU Delft提出了所谓的WRW室内声学建模概念，该概念来源于石油和天然气地震勘探中常用的建模方案。WRW模型的计算方案是基于声波方程的。矩阵R描述了房间边界的局部反射特性，矩阵W表示了每个边界点之间的声音传播。本子项目的目标是将WRW模型从一个有吸引力的概念发展成为一个可操作和高效的仿真工具。为了实现这一目标，应确定房间边界的反射特性的适当描述，并将其插入矩阵r中。在通过麦克风阵列测量数据的逆外推确定这些特性后，必须编制常见边界结构的这种反射率特性库。还必须研究如何用最有效的计算方法来计算由矩阵W描述的所有边界点之间的声音传播。子项目的最终产品应该是一个仿真软件包，能够准确和预测地模拟复杂箱体中的三维声波场，作为研究的参考工具。

Round-robin tests during the last decades have convincingly shown that the common geometric modelling schemes where diffraction and scattering of sound are not adequately taken into account do not reliably predict sound fields in enclosed spaces. As a modelling tool in which the physical properties, i.e., the wave character, of sound is fully taken into account, TU Delft proposed the so-called WRW room acoustics modelling concept, derived from a modelling scheme commonly used in seismic exploration of oil and gas. The calculation schemes of the WRW model are based on the acoustic wave equation. Matrices R describe the local reflective properties of the room boundaries, matrices W specify the sound propagation to and from each boundary point. Goal of this subproject Is to develop the WRW model from an attractive concept to an operational and efficient simulation tool. To realize this goal, an appropriate description of the reflective properties ofthe room boundaries should be determined, to be Inserted in the matrices R. A library of such reflectivity properties for common boundary constructions has to be compiled, after determination of these properties by inverse extrapolation of microphone array measurement data. It also has to be investigated how the sound propagation between all boundary points, as described by the matrices W, can be calculated In a computationally most effective way. The end product of the subproject should be a simulation software package enabling the accurate and predictive simulation of 3D acoustic wave fields in complex enclosures, as a reference tool for research.