Two‐dimensional angle of arrival fluctuations
作者:
Daniela Di Iorio,
David M. Farmer,
期刊:
The Journal of the Acoustical Society of America
(AIP Available online 1996)
卷期:
Volume 100,
issue 2
页码: 814-824
ISSN:0001-4966
年代: 1996
DOI:10.1121/1.416241
出版商: Acoustical Society of America
数据来源: AIP
摘要:
Angle of arrival fluctuations are one manifestation of acoustic propagation through a turbulent flow. Here the two‐dimensional angle of arrival distribution for a 670‐m acoustic path through a high Reynolds number flow in a tidal channel is examined and its origin and relationship to the flow field is determined. Over scales greater than the variability due to turbulence, a solution of the ray propagation equation explains the effect of advection on the horizontal arrival angle. The rapidly fluctuating two‐dimensional angle of arrival distribution shows a degree of scatter consistent with the level of turbulent intensity. After removal of effects due to the finite aperture, orthogonal components are correlated during strongly sheared flow implying that the turbulence is weakly anisotropic over the measured scales. This anisotropy is discussed in terms of the cross stream velocity gradients ∂v/∂x′ and ∂v/∂z′, where (x′,z′) are perpendicular diagonal coordinates.
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