Turbulence under spilling breakers using wavelets

Measurements of the kinetic energy of turbulence under spilling waves have been analysed using orthogonal wavelets. Data have been collected using 2-D laser Doppler velocimetry for pre-breaking regular waves, generated in a wave tank. The contribution of different scale vortices is computed, and also phase resolved. It is found that micro-vortices (2 mm <l<0.10 m for the tested case) and mid-size vortices (0.10 m<l<4.0 m for the tested case) are generally dominant, carrying more than 70% of the total turbulence energy under the wave crest. The phase resolved energy spectra are computed, which allows the computation of the transverse and of the longitudinal correlations.