应用几何绕射理论，研究不同角度和不同频率情况下楔形障碍物衍射衰减规律，并结合90°楔形障碍物现实应用，模拟楔形建筑物下声音传播衰减。得出了楔形障碍物插入损失与楔形角度和声波频率的关系，结果与Maekawa实测值比较并进行精度分析。针对现实场景下楔形建筑物的遮挡，应用空间剖分和声线束追踪生成声音路径，模拟楔形建筑物区域的声音衰减。结果显示声音衰减随楔形角度减小和频率增加而增大，几何绕射理论可应用于大区域建筑物群声传播衰减计算中。%Geometrical theory of diffraction is used to study the diffraction rules of wedge-shaped obstacle with different angles and sound frequencies. A wedge-shaped obstacle with 90° wedge angle is taken as a typical example to simulate sound propagation and attenuation of wedge-shaped buildings. The relation of the insertion loss and the wedge angle of the obstacle and the sound frequency are obtained. The result of simulation is compared with the Maekawa’s measurement data and the accuracy of the simulation is analyzed. Considering the sheltering effect of the in-situ wedge-shaped buildings, sound attenuation amid the buildings is calculated with the help of spatial subdivision and beam tracing method when the sound path is generated. The results show that the sound attenuation increases with the decreasing of the wedge angle and increasing of the sound frequency. And the geometrical theory of diffraction can be applied to the sound diffraction calculation amid buildings in a large area.
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