Abstract
On-offshore and vertical water particle velocities in surf zones on beaches in wave tanks are measured with a hot-film anemometer and a two-component laser-doppler velocimeter. Turbulence generated by wave breaking is estimated. Vertical distribution of turbulence intensity inside the surf zone is discussed in comparison with the vertical distribution of eddy diffusion coefficient in surf zone. Time variation of turbulence intensity during one wave period can be explained by extending the turbulent wake theory. Time variation of Reynolds stress during one wave period shows a similar trend as that in oscillatory pipe flow. Reynolds stress, which is defined here, may not play an important role in the on-offshore momentum transfer in a time scale shorter than the wave period.
