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Indexed by:期刊论文

Date of Publication:2009-01-01

Journal:ACTA OCEANOLOGICA SINICA

Included Journals:SCIE、CSCD、Scopus

Volume:28

Issue:4

Page Number:96-106

ISSN No.:0253-505X

Key Words:alongshore currents; shear instability; water waves; coast

Abstract:A laboratory experiment on the instability of alongshore currents was conducted on a plane beach with slope 1:40. Low-frequency fluctuations of alongshore currents with the period of approximately 100 s were observed. The dominant frequency and amplitudes of the oscillations of alongshore currents were determined using the maximum entropy method and the regression method of trigonometric function. The variations across the beach cross-section of the oscillation amplitudes of the alongshore current were given. The linear shear instability theory was used to analyze the mechanism of the oscillation, and the calculated results agreed with measurements. This confirms that the observed fluctuation of alongshore currents is due to the shear instability of alongshore currents.