Experimental Study on Crescent Waves Diffracted by A Circular Cylinder

摘要

Crescent waves often observed on the sea surface are unusual wave pattern induced by the instability of Stokes wave.The paper presents the experimental results of the wave field around a circular cylinder generated by the diffraction of crescent wave in order to examine the difference of diffracted crescent waves from the commonly-used diffracted Stokes waves. The results show that with the existence of the cylinder, the crescent wave pattern can still get fully developed, and with the presence of this type of wave pattern, the symmetry breaking of the wave amplitude distribution occurs and there are extra wave components at the frequencies of 0.5 ω_0, 1.5ω_0 and 2.5ω_0(ω_0 is the frequency of Stokes waves) appearing in the wave amplitude spectrum.