耦合空间中声能衰变的辐射度模型

基于界面扩散反射的声辐射度模拟方法在单一空间中已得到有效的应用．文中针对耦合空间中的声能衰变，提出一种改进的声辐射度模型．该模型将耦合开口设置为分属于两个子空间的虚拟界面，在每个计算时间步长内，对各子空间中声辐射度进行独立计算，并通过虚拟界面上声辐射度的接收和传播实现子空间声能的交换．改进模型可有效降低计算量，提高计算效率，同时克服了不同子空间中面元的可见性判断所产生的误差，提高了模拟的收敛速度．与实测结果的对比表明．改进模型对耦合空间中的声能衰变具有较好的预测精度．

A Radiosity Model for Sound Decay in Coupled Rooms

The acoustical radiosity method, which assumes diffusely reflecting boundaries, has recently been developed to predict the sound fields in single-volume rooms. This research aims at the performance of this method in coupled rooms, and proposes an improved model based on acoustical radiosity to predict the sound decays in a system of two coupled rooms. In the proposed model, the coupling aperture is considered as two virtual surfaces and the radiosity on these surfaces is employed to implement the sound energy transmission between two subrooms. Therefore, the radiosity can be computed individually in each subsroom, and the computation cost is significantly reduced. Moreover, the proposed model avoids errors from visibility detecting for elements in different subrooms. The predictions of sound decays have satisfactory convergence and agree well with those obtained by measurements.