列车运行噪声的几何发散损失

根据基本声学理论,分析具有单极子、中间和偶极子三种指向性的有限长线声源的几何发散损失特性。给出适合铁路列车运行噪声特点的几何发散损失计算方法。指出现行有关标准的计算方法存在声源指向性不明确、计算方法误差偏大和不适合铁路列车运行噪声等缺点。推荐铁路列车运行噪声几何发散损失计算采用偶极子指向性特性的理论计算公式或简化公式。

Geometrical Spreading Loss of Running Train Noise

Based on the theory of acoustics, this paper analyzes the character of geometrical spreading loss of finite line sound source on three types of directivity-monopole, intermediate pole and dipole. A calculation method for geometrical spreading loss is provided which is adapted to the characteristics of running trains noise. It points out that the current calculation methods of related standards exist such weaknesses as unclear directivity of sound source, greater error of the calculation method and unsuitable for running trains noise etc. It recommends that the calculation of geometrical spreading loss of running trains noise adopt the theories calculation formula or the simplified formula of directional characteristic of dipole.