Abstract
<jats:p>Diffraction of regular waves by arrays of vertical bottom-mounted circular cylinders is
investigated using theoretical, computational, and experimental methods. Experiments
in an offshore wave basin are designed to measure free surface elevation η at multiple
locations in the vicinity of a multi-column structure subjected to regular waves
of frequency 0.449 < <jats:italic>ka</jats:italic> < 0.524 and steepness 0.122 < <jats:italic>kA</jats:italic> < 0.261, where <jats:italic>k</jats:italic> is the
wavenumber, <jats:italic>a</jats:italic> the cylinder radius and <jats:italic>A</jats:italic> the wave amplitude. Results from regular
wave data analysis for first-order amplitudes are compared with those from analytical
linear diffraction theory, which is shown to be accurate for predicting incident waves
of low steepness. Second- and third-order terms are also estimated from the measured
time series, and the effects near a second-order near-trapping frequency are compared
to semi-analytical second-order diffraction theory. Linear diffraction theory is shown
to be very accurate at predicting the global surface elevation features, even for waves
of high steepness. However, violent events and significant nonlinear interactions,
including breaking induced by wave scattering, have been observed. Furthermore,
second-order near-trapping was observed to affect the magnitude of local free surface
oscillations as well as scattered far-field radiation.</jats:p>
Original language | English |
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Pages (from-to) | 1-32 |
Number of pages | 0 |
Journal | Journal of Fluid Mechanics |
Volume | 442 |
Issue number | 0 |
Early online date | 24 Aug 2001 |
DOIs | |
Publication status | Published - 10 Sept 2001 |