nalysis of Low frequency Noise Emitted from High-speed Train with Fluid Model

在山梨市磁悬浮试验线上，测量到了高速列车发出的低频噪声。研究了噪声随距离的衰减、声级随列车速度的增加以及隧道入口(引擎盖)对低频噪声的影响，并在实验室进行了1/100高速列车模型的低频噪声产生实验。测量了声场随距离的衰减和声级随列车速度的增大。这些特性与山梨市磁浮试验线的测量结果相吻合。结果表明，采用势流模型对高速列车产生的低频噪声进行了数值分析。声级随列车速度的增加可以从流体模型中得到数学解释。通过数值模拟，解释了声衰减随距离的变化、声级随列车长度的变化以及频率特性随距离的变化规律。结果表明：a NuMe…利用高速列车周围的势流模型，对高速列车产生的低频噪声进行了更为细致的分析。声级随列车速度的增加可以从流体模型中得到数学解释。通过数值模拟解释了声衰减随距离的变化、声级随列车长度的变化以及频率随距离的变化特性，并用势流模型对高速列车产生的低频噪声进行了数值分析。声级随列车速度的增加可以从流体模型中得到数学解释。通过数值模拟解释了声衰减随距离的变化规律、声级随列车长度的变化规律以及频率特性随距离的变化规律，并利用模型列车实验装置考察了隧道入口对低频噪声的影响。隧道入口增加了隧道入口周围的低频噪声水平。这些结果可以较少地预测高速列车产生的低频噪声水平

A low frequency noise emitted from a high-speed train was measured at the Yamanashi maglev test line. Sound attenuation with distance, increase of sound level with train speed and influences of a tunnel entrance (hood) on low frequency noise were investigated.Experiments on low frequency noise generation with a 1/100 high-speed train model at a laboratory were carried out. Sound attenuation with distance, and increase of sound level with train speed were measured. These characteristics are accorded to the measurements of the Yamanashi maglev test line.It was shown that a numerical analysis of the low frequency noise generated by a high-speed train was done with a potential flow model around a high-speed train. The increase of sound level with train speed can be explained mathematically from the fluid model. The sound attenuation with distance, the sound level with train length and the frequency characteristics with distance are explained by numerical simulation.It was shown that a nume … More rical analysis of the low frequency noise generated by a high-speed train was done with a potential flow model around a high-speed train. The increase of sound level with train speed can be explained mathematically from the fluid model. The sound attenuation with distance, the sound level with train length and the frequency characteristics with distance are explained by numerical simulation.It was shown that a numerical analysis of the low frequency noise generated by a high-speed train was done with a potential flow model around a high-speed train. The increase of sound level with train speed can be explained mathematically from the fluid model. The sound attenuation with distance, the sound level with train length and the frequency characteristics with distance are explained by numerical simulation.The influence of a tunnel entrance on the low frequency noise was examined with the model train experimental equipment. A tunnel entrance increases the level of low frequency noise around the tunnel entrance.The level of low frequency noise generated bye the high-speed train can be predicted with these results Less