IMPLICATIONS OF SECOND-ORDER WAVE GENERATION FOR USE IN WAVESTRUCUTRE RESPONSE EXPERIMENTS

Abstract

Coastal communities and critical coastal assets are therefore increasingly reliant on engineered protection from wave-induced flooding. Dynamic wave force and wave run-up are among key design parameters of such protection. Present understanding of coastal wave-structure interactions and responses was gained through large databases of experimental data as well as numerical, and field measurements. It is well known that experimental data of wave-structure interaction are contaminated by second-order error waves at sub- and super-harmonic frequencies when first-order wave generation is used. The error waves arise from disparity between linear wave-maker signals and non-linear boundary conditions at the wave generator. Herein, we conduct a novel investigation by experiment of the implications of second-order wave generation for dynamic wave force and run-up on a vertical wall, in shallower depths than previously published (kd = 0.6 - 1.1). The implications of error waves on coastal responses is quantified through comparison of first-order generated (FOG) and secondorder generated (SOG) wave group experiments.