MEASUREMENTS OF SURF BEAT AND SET-DOWN BENEATH WAVE GROUPS

Proceedings of the International Conference on Coastal Engineering

J.K. Kostense¹ 

[1] Delft Hydraulics Laboratory

关键词: surf beat;    set down;    wave groups;    surf beat measurement;    set down measurement;   

DOI  :  10.9753/icce.v19.%p

学科分类：建筑学

来源: Coastal Engineering Research Council

【 摘 要 】

A laboratory study was conducted to measure the amplitudes of long waves In shallow water as induced by wave grouping. In a 55 m long wave channel with a plane beach at the end, two primary waves of nearly equal frequency were generated. Due to a sophisticated control of the wave paddle - including second order wave generation as well as active wave absorption at the paddle face - the wave action at the difference frequency was limited to an incident forced wave, propagating at the group velocity, and a reflected free wave generated in the surf zone. For the incident forced - or bound - wave, also known as set-down, the experimental results show good agreement with the existing theory. Furthermore, the experiments confirm qualitatively a theoretical model by Symonds et al. (198 2) explaining two-dimensional surf beat as a result of the time-varying breakpoint of the incident primary waves.

【 授权许可】

Unknown