Open AccessVELOCITIES UNDER PERIODIC AND RANDOM WAVES
Author(s) -
Allen Lee,
Clive Greated,
T.S. Durrani
Publication year - 1974
Publication title -
proceedings of conference on coastal engineering/proceedings of ... conference on coastal engineering
Language(s) - English
Resource type - Journals
eISSN - 2156-1028
pISSN - 0589-087X
DOI - 10.9753/icce.v14.31
Subject(s) - optics , physics , distortion (music) , elevation (ballistics) , acoustics , grating , sign (mathematics) , computational physics , mathematics , mathematical analysis , amplifier , optoelectronics , cmos , astronomy
Using the linear approximation for predicting velocities under periodic water waves, relationships are established between the velocity spectrum and the surface elevation spectrum for three-dimensional waves. The two dimensional forms of these relationships are used for comparison with velocity and elevation spectra measured in a laboratory wave tank. The predicted distortion of the spectrum shape can be observed in the experimental results. Velocity measurements were recorded using a laser velocimeter employing a rotating diffraction grating for shifting the optical frequencies. This allows measurement without sign ambiguity. The random waves were generated using a servodriven paddle with a filtered white noise input.