半球封闭圆柱体表面绕射声场研究

基于一致性几何绕射理论,对半球封闭圆柱体上半球表面的高频绕射声场进行了数值计算与分析。获得了单个点声源作用下,半球表面声场的声压分布图,其中包括一些干涉条纹,干涉条纹的区域及形状与点声源的位置和频率有关;在多个点声源作用下,发现在接近半球顶点的附近,多个声波经多途传播后在该区域的叠加声压由衰减转为增强的现象。

An analysis of the diffracted sound fields on the surface of a hemispherically terminated cylinder

An approximate solution is presented for the diffracted sound fields on the surface of the hemisphere of a hemispherically terminated cylinder by the use of the uniform geometrical theory of diffraction. The distribution of the sound pressure with some interference stripes are obtained, which are induced by a point source on the cylindrical surface. The area and the shape of the interference strips depend on the locality and the frequency of the point source. Acted by multiple sources, it is discovered that in the neighborhood of the tip point of the hemisphere, after multi-path spread of the sound waves, the sound pressure is turned from decreasing to increasing.