Field of point source of low-frequency sound in atmosphere with altitudinally nonuniform wind
Abstract
The problem of propagation of infrasonic waves from a point source through a stratified moving atmosphere is solved almost exactly, analytically, or the case of an altitudinally nonuniform purely horizontal wind. The harmonic point source is assumed to be close to or on the ground and the wind velocity is assumed to vary vertically with an exponential profile Vx(2)c = V(0)c (1-3 to the -2/h power) (V-horizontal wind velocity; c- acoustic velocity, h- characteristic scale of altitudinal wind nonuniformity). The corresponding equation for the quasi-potential velocity is solved for the altitudinal amplitude profiles of the zero-order normal wave in a narrow atmospheric waveguide (k(0)h = 1) and in a wide atmospheric waveguide (k(0)h = 2 pi), as well as of the third-order normal wave (k(0)h = 22) and the sixth-order normal wave (k(0)h = 40). From the solution is also determined the dependence of the wave field amplitude and phase on the distance from the source. Results are based on k(0)h V x/c (k(0) - wave number) and V(x) c, with h = 30 m (approximately the wavelength of sound).
- Publication:
-
USSR Rept Electron Elec Eng JPRS UEE
- Pub Date:
- March 1985
- Bibcode:
- 1985RpEEE........1C
- Keywords:
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- Acoustic Velocity;
- Atmospheric Attenuation;
- Infrasonic Frequencies;
- Low Frequencies;
- Wind (Meteorology);
- Numerical Analysis;
- Point Sources;
- Waveguides;
- Wavelengths;
- Acoustics