Abstract Geometry of cabins, corridors, and materials used in railway passenger carriages can play important roles in acoustic performance inside the rail cars. In order to evaluate the noise level inside a rail car, a hybrid method based on the ray-tracing and image-source techniques is employed. A parametric model is constructed based on the field experiment performed in a typical coach cabin namely Fadak train in Iranian Railway. An Omni-directional sound source inside the passenger carriage is employed inside the cabin once for an unequipped cabin and once for operational one. Acoustic parameters such as reverberation time (T30), Center time (Ts), and the sound pressure level have been calculated and results are validated with experimental acoustic measurements. The model is experimentally calibrated and then acoustics performance of the passenger coach is enhanced by modifying the materials and absorption coefficients against two dominant sound sources in low to middle speed ranges. It is found the simple recommendation can remarkably enhance the acoustic performance over a broad range of frequencies.

中文翻译：

---

使用混合射线追踪和图像源方法提高铁路客车的声学性能

摘要 轨道客车车厢、走廊和材料的几何形状对轨道车内的声学性能起着重要的作用。为了评估轨道车内的噪声水平，采用了一种基于光线追踪和图像源技术的混合方法。参数模型是基于在典型的客舱（即伊朗铁路的 Fadak 列车）中进行的现场实验构建的。客车内的全向声源在客舱内使用一次，用于未配备的客舱，一次用于可操作的客舱。已经计算了混响时间 (T30)、中心时间 (Ts) 和声压级等声学参数，并通过实验声学测量对结果进行了验证。该模型经过实验校准，然后通过修改材料和吸收系数以针对中低速范围内的两个主要声源来提高客车的声学性能。发现简单的推荐可以显着提高广泛频率范围内的声学性能。