The effects of the source and ground parameters on outdoor sound propagation using the FDTD

• Published in: The Journal of the Acoustical Society of America 2012-04, Vol.131 (4_Supplement), p.3332-3332
• Main Authors: Kaifeng, Han, Xinwu, Zeng, Zhenfu, Zhang
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4708469

The sound propagation outdoors is widely studied in several areas such as transportation noise mitigation, biological studies, security and military activities. Several special factors are important when sound waves propagate more-or-less horizontally near the ground, such as ground characteristics, the use of sources and so on. The simplest effect of the ground on the sound field is the interference between the direct and reflected sound fields. However, the ground surfaces are neither rigid nor impervious to air flow; it will cause higher sound energy loss. Secondly, the parameters of the source distribution and the frequency emission also determine the amount of loss. To quantify the influences of the source parameters and inhomogeneous ground conditions on the sound field outdoors, a practical FDTD implementation is constructed in this paper. The mixed influence of ground characteristics and source conditions are then included. The numerical results showed the source distribution and the frequency had large effects on the actual sound pressure measurement in the specific situation. The ground boundary conditions are the main effects on the basic phenomena of outdoor sound propagation.