Atmospheric sound propagation using a three-dimensional parabolic equation
Abstract
A numerical method for solving the 3D parabolic wave equation (3DPE) is presented to investigate long range sound propagation in the atmosphere near the ground. An implicit finite-difference scheme based on the alternating directions method is formulated. The pressure field is calculated in cylindrical coordinates for all the 0 to 360 deg azimuth range, so that only a periodicity condition is required. A hard reflecting ground is considered and a homogeneous boundary condition is applied at the top of the mesh. The validity of the 3DPE is shown by comparison with measurements carried out in an anechoic chamber. The diffraction of sound behind a thin barrier of finite length is studied. A good agreement with calculations is obtained for the sound pressure level behind the barrier. In particular, the term involving azimuthal derivatives is taken into account in the 3DPE and enables to calculate properly the diffraction from both side edges of the screen.
- Publication:
-
ONERA TP
- Pub Date:
- 1992
- Bibcode:
- 1992ONERA....Q....D
- Keywords:
-
- Atmospheric Physics;
- Finite Difference Theory;
- Parabolic Differential Equations;
- Sound Propagation;
- Wave Equations;
- Boundary Conditions;
- Cylindrical Coordinates;
- Pressure Distribution;
- Acoustics