Experimental investigation of wave tip variability of impacting waves

Abstract

52 peatable and is used to model and scale the pressure of 53 wave impact experiments. 9,10,14-16 In recent years, the 54 study of liquid sloshing 17-21 and slamming on both wave 55 energy converters 22-24 and floating offshore structures 3 56 has received considerable attention. The peak impact 57 pressure is especially relevant in these applications. 3,4 58 A number of reviews have been published both on 59 extreme wave impact events and sloshing. For exam-60 ple, the effect of liquid sloshing impacts has been thor-61 oughly reviewed by Ibrahim 25. A detailed review of wa-62 ter wave impacts on vertical walls is presented by Pere-63 grine 4 , whereas Dias and Ghidaglia 26 present a detailed 64 review on slamming. The impact of a wave can be di-65 vided into several elementary loading processes, such as 66 the direct impact, the jet deflection, and the compres-67 sion of the entrapped or escaping gas. 20 Different types 68 of wave impact can be defined by a combination of el-69 ementary loading processes. The classification of wave 70 impact type depends on the wave shape prior to impact, 71 which is either classified as a slosh, a flip-through, a gas 72 pocket, or an aerated type of wave impact. 4,7,27 For ex-73 ample, the flip-through wave impact has been studied 74 in detail with and without hydro-elasticity. 28,29 The ef-75 fect of hydro-elasticity is relevant for all wave impact 76 types. 30 The flip-through wave impact only occurs for a 77 limited parameter space. 4 On the other hand, the impact 78 of a plunging breaking wave occurs for a wider parameter 79 space and often results in a gas pocket type wave impact. 80 The impact type can easily be identified, but scaling of 81 wave impacts from small-scale to large-scale experiments 82 is not straightforward.

Breaking-wave induced pressure and acceleration on a clifftop boulder

“…Throughout the breaking process, the wave crest drastically changes shape and entrains air (Deike, Melville & Popinet 2016;Melville & Rapp 1985). The fast velocities, changing crest shape, fluid mixing and rapid development of breaking waves over a fraction of a wavelength means that, throughout breaking, the measured pressures at an impacted structure vary significantly even across globally similar waves (van Meerkerk et al 2020). Additionally, third-order wave-wave interactions at a fluid-structure interface can increase wave run-up height by twice that expected by linear wave theory (Zhao et al 2017) and the run-up of long waves can be amplified up to 12 times through nonlinear dispersion, reflection, interference and abrupt changes in bathymetry (Herterich & Dias 2019;Viotti, Carbone & Dias 2014).…”