| Autor: |
Jakjoud, Hicham, CHITNALAH, Ahmed, Noureddine, Aouzale, Kourtiche, Djilali |
| Zdroj: |
Proceedings of Meetings on Acoustics; 2008, Vol. 4 Issue 1, p045001-045001-6, 1p |
| Abstrakt: |
It's well known that the harmonic imaging quality can be improved by using sources that radiate narrower and attenuated sidelobes beams. Hence we try to enhance the harmonics' cartography by studying different source's power distributions. We developed a numerical code, using the spectral method, in order to resolve the parabolic wave equation. The numerical results were compared to the results given by Bergen code in order to validate our algorithm. Two source's power distributions (exponential and Bessel beams) were studied and compared to the uniform case. The use of exponential source leaded to harmonics diagrams without sidelobes neither nearfield oscillations. But the beam width was increasing with propagation. The Bessel source presents a limited diffraction beam. The beam width is almost constant throughout the nearfield and the transition zone. The sidelobes had a weak level in the fundamental curves and they don't appear in the second harmonic ones. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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