Hydrodynamic modulation of sea free and bound waves modulated by the one-dimensional variant current

There exist bound gravity-capillary waves that move at the speed of the dominate waves on the ocean surface, apart from free gravity-capillary waves that satisfy the linear dispersion relation. So far, however, the modulation characteristics of these bound waves are little studied. Thus, we carried out two sets of experiments on bound wave scattering and modulation by underwater bottom topography in wind-wave tank of SJTU. Experiment results show that the wave-current modulation level of bound waves is stronger than free waves and different from free waves on the trend. The modulation mechanism of free waves is in consistent with the classic wave-current modulation theory. Meanwhile the modulation of bound waves is similar as the long waves.