Hydrodynamics in the swash zone

This paper describes a study of the hydrodynamics in the swash zone using an impermeable concrete beach in a laboratory flume. Analysis was made of the measurements achieved using level wave gauges and a laser Doppler velocimeter. From these measurements we could derive the mean motion and turbulence characteristics along the main flow direction in three vertical sections of the swash zone. Fluid velocity seems almost uniform along the vertical, especially during the up-rush; the behaviour of turbulence dynamics is a mixture of free turbulence generated during wave breaking and convected by the mean motion, and wall turbulence. This work covers analysis in the time and frequency domain and the turbulent properties of the flow field derived from our measurements are discussed.