Abstract
Three-dimensional fluid velocity field in a surf zone was experimentally investigated to obtain spatial characteristics of mean flow, such as return current, and turbulence flow caused by wave breaking. It is possible that three-dimensional organized vorticities, generated after breaking, indirectly affect to mean flow and induce three-dimensional steady flow. In two-dimensional wave flume, return current contributes three-dimensionality of fluid motion in a surf zone. The effect of return current to a front bore is also investigated by the particle image velocimetry.
