Temat: frequency shift - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Sound waves in a wave noise
Autorzy:: Murawski, K.
Tarnowski, M.
Powiązania:: https://bibliotekanauki.pl/articles/1955702.pdf
Data publikacji:: 2004
Wydawca:: Politechnika Gdańska
Tematy:: sound waves
random waves
frequency shift
amplitude alteration
Opis:: We examine by analytical and numerical means sound waves which propagate in a space- and time-dependent random mass density field in the form of dispersionless wave noise of its spectrum E(kappa,omega) ~ E(kappa) delta (omega-crk), where cr is a random speed. Numerical simulations are in agreement with the analytical theory which shows that at cr=omega/k resonance occurs and the cyclic frequency omega tends to infinity. For values of cr which are close to the resonance point, the sound waves are slowed down and attenuated (accelerated and amplified) for cr < omega/k (cr > omega/k).
Źródło:: TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2004, 8, 1; 103-108
1428-6394
Pojawia się w:: TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Numerical simulations of sound wave generation in a random medium
Autorzy:: Murawski, K.
Selwa, M.
Powiązania:: https://bibliotekanauki.pl/articles/1955700.pdf
Data publikacji:: 2004
Wydawca:: Politechnika Gdańska
Tematy:: sound waves
random waves
frequency shift
amplitude alteration
Opis:: In turbulent media, both sound wave sources and the speed of sound can be stochastic variables. By means of numerical simulations of one-dimensional Euler equations with random source terms we have studied two cases in a homogeneous stochastic random medium for which the speed of sound and sound sources are: (1) correlated and (2) uncorrelated. The numerical simulations indicate that, if the source and the speed of sound fluctuations are uncorrelated, the acoustic field is incoherent, with a zero expectation value. The mean field is non-zero in the correlated case. The correlated and uncorrelated cases are clearly distinguishable by the mean field, but also - to some extent - in the power spectrum, which displays a modified Lorentzian profile with a shift in frequency.
Źródło:: TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2004, 8, 1; 109-114
1428-6394
Pojawia się w:: TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:: Biblioteka Nauki

Artykuł

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