Tong Feng

Kinematics and depth-integrated terms in surf zone waves from laboratory measurement

Kinematics of nominally periodic surf zone waves have been measured in the laboratory using LDA (laser Doppler anemometry), above trough level as well as below, for weakly plunging breakers transforming into bores in shallower water. The aim was to determine, through phase- or ensemble-averaging, periodic flow structures in a two-dimensional vertical plane, from large-scale down to small-scale vortical structures. Coherent multiple vortical structures were evident at the initiation of breaking, becoming elongated along the surface during bore propagation. The initial region is likely to become more extensive as waves become more strongly plunging and could explain the difference in turbulence characteristics between plunging and spilling breakers observed elsewhere

Kinematics of a Focused Wave Group on a Plane Beach: Physical Modeling in the UK Coastal Research Facility

This paper presents results of surface elevation and kinematics measurements made in the UK Coastal Research Facility (UKCRF). Investigations were made into the behavior of focused wave groups as they ran up and overtopped a plane beach and a sea wall. Measurements of the kinematics of focused wave groups were made using an acoustic Doppler velocimeter (ADV) and a laser Doppler anemometer (LDA). Kinematics results from the LDA alone are presented in this paper. Analysis of the data has revealed information about the harmonic structure of the wave group both for surface elevation and kinematics.