境界積分方程式法による広域3次元音場波動解析法の開発とその応用
本稿は、境界積分方程式法(BIEM)を用いた広域の3次元音場の波動解析について述べる。鏡像を用いたGreen関数を導入して地盤面の要素分割を不要にする事によって計算負荷が低減できる。それゆえ、膨大な要素が必要とされるFEMやFDMより、広域、高周波数の解析が可能となる。また、従来の幾何解析法では十分な計算精度が確保できなかった回折や多重反射等を厳密に再現する事ができ、複雑な音場も取り扱う事ができる。
Three Dimensional Acoustic Wave Motion Analysis of Wide Area by Boundary Integral Equation Method (BIEM) and its Application
This paper presents 3-D analysis of wave propagation over the wide area, such as a urban block by use of boundary integral equation method(BIEM). By introducing the Green’s function using the mirror image about the ground surface, the element division of the ground surface becomes unnecessary, and the calculation load is mitigated. Therefore, this analysis method is more useful than others such as FEM and FDM which need a lot of elements, and enable to analyse problems of a large area to relatively high-frequency. In addition, it is able to deal with a sound field complicated with diffraction, multiplex reflection, etc., which the conventional geometric analysis method cannot give good accuracy.