Bi-orthogonal decomposition and Wavelet transform to analyse kinematics and dynamics of surface waves

概要

論文の詳細を見る
A row of discrete vortices is superposed to an air-sea interface to modelize the generation of surface waves by wind. A numerical method is developed in order to take into account the nonlinear effects which occur in the evolution of surface waves with finite steepness. The shape of the excited surface waves range from quasi sinusoidal to asymmetrical profiles close to breaking. Bi-orthogonal decomposition shows that resonant excitation (amplification of wave amplitude) may occur both at the fundamental frequency and at its second harmonic. This deterministic physical model is compared with experiments conducted in an air-sea tunnel. A vortex street is artificially created in the air flow. Using Fourier analysis and Wavelet transform it is found, in agreement with the numerical formulation, that non-sinusoidal disturbances advected over the water surface can have harmonic components that interact resonantly to generate surface waves, even thought the basic (fundamental scale is non-resonant.
社団法人日本船舶海洋工学会の論文