Experimental Study of Rip Currents of Intersecting Irregular Waves

Abstract:

To better understand the characteristics of rip current caused by crossing irregular waves，an experimental study of rip current caused by intersecting irregular waves over barred beaches was conducted. The barred beach without rip channel was adopted to eliminate the inconsistency of coastal topography caused by the rip channel，so that the rip currents was mainly controlled by the node points of waves. The driving force of the rip current is mainly the mean water surface pressure gradient pointing to the node，while the radiation stress caused by wave height contributes little due to the change of wave height along the break zone. The magnitude and range of the driving force are affected by the period. The location and width of rip currents are controlled by the wave node points. The cross-wave field forms an alternate circulation system and large-scale vortex in the alongshore direction. The circulation system includes the rip currents around the wave node points，the onshore current around the wave anti-node points，and the longshore feeder currents from the anti-node to the wave node points.