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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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Statistical properties of nonlinear N-wave propagating in thermal or kinematic turbulence. (165th Meeting of the Acoustical Society of America)статья
Дата последнего поиска статьи во внешних источниках: 27 мая 2015 г.
- Авторы: Yuldashev P., Ollivier S., Khokhlova V., Blanc-Benon Ph
- Журнал: Journal of the Acoustical Society of America
- Том: 133
- Номер: 5
- Год издания: 2013
- Издательство: Acoustical Society of America
- Местоположение издательства: United States
- Первая страница: 3507
- DOI: 10.1121/1.4806249
- Аннотация: Nonlinear propagation of high amplitude N-wave through turbulent layer is studied using 2D KZK-type nonlinear parabolic equation. The incident acoustic wave is assumed to have a plane wavefront and the waveform is a classical symmetrical N-wave. The turbulent layer is synthesized using a method of random Fourier modes. The modified von Karman spectra with the same values of outer and inner scales are considered for both scalar-type (temperature fluctuations) and vector-type (velocity fluctuations) turbulent fields. The rms value of the refraction index fluctuations μrms is varied as a parameter. It is shown that statistical characteristics of N-wave propagating in vector-type or scalar-type turbulent fields are equivalent when almost twofold scaling of μrms is considered. The distance of most probable occurrence of caustics obtained in the KZK simulations which account for diffraction effects is demonstrated to be proportional to μrms-1 while the geometrical acoustics approach predicts the proportionality to μrms-2/3. Non-monotonic effect of the initial N-wave amplitude on the maximum pressure values in the field is analyzed. The enhancement of focusing efficiency in caustics is observed for moderate initial amplitudes of N-wave, whereas strong nonlinearity is shown to reduce pressure amplitudes in random foci. The work is supported by PICS RFBR 10-02-91062/CNRS 5603 grants.
- Добавил в систему: Хохлова Вера Александровна