鉄道車両における車内前後方向への音の伝搬を考慮した車内音予測手法の基礎的検討

抄録

The purpose of this paper is to build an estimation method of interior noise reduction effects due to structural changes during the early design stages at any position within the railway vehicle. We examined a model of a sound energy density propagation and proposed the model that considers both direct and diffuse sound. Additionally, we applied the proposed model to the floor section of a railway vehicle. As a result, we confirmed that the estimated values of the contribution rate about sound energy density decrease as the distance from the measurement point increases, indicating that the estimation results are qualitatively reasonable. Furthermore, it was confirmed that the cumulative contribution rate is approximately 75% outside the range of ±1m from the measurement point. This suggests that when the acoustic power of each element is comparable, the influence of sound propagating from the front and rear directions of the vehicle on the interior noise level cannot be ignored.