声波爆发在真实地形上的传播
Ariane Emmanuelli1, Didier Dragna1, Sébastien Ollivier1
1Univ Lyon, Ecole Centrale de Lyon, CNRS, Univ Claude Bernard Lyon 1, INSA Lyon, LMFA, UMR5509, 69130, Ecully, France.
The Journal of the Acoustical Society of America
|July 5, 2023
概括
地形的高度显著影响了声波波的反射. 丘陵地形可以将噪音水平放大至多6dB,这是由于波面折叠造成的,特别是在的斜坡上.
科学领域:
- 声学 声学 在声学方面
- 计算流体动力学的流体动力学.
- 地质物理学 地质物理学
背景情况:
- 超音速飞机产生的声波爆发可能会受到地面地形的影响.
- 了解这些影响对于预测噪音影响和公众接受度至关重要.
研究的目的:
- 为了研究现实地形的高度变化如何影响声波波的反射.
- 量化地形对声波特征和噪声水平的影响.
主要方法:
- 使用有限差异时间域技术解决二维欧勒方程.
- 在丘陵地区的10公里长地形上进行数值模拟.
- 分析两种类型的爆发波:经典的N波和低爆发波.
主要成果:
- 地形显著改变了对温和和坡的反射声波爆发.
- 由于地形低谷造成的波面折叠是主要观察到的现象.
- 坡导致噪声水平放大,在1%的位置上增加3dB,在低谷附近增加5-6dB.
结论:
- 地形的高度变化,特别是的斜坡和低谷,大大影响声波波的反射,增加噪音水平.
- 波面折叠是这种放大的一个关键机制.
- 这些发现适用于N波和低波,为未来超音速飞行噪声预测提供信息.
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