Are breaking waves, bores, surges and jumps the same flow?

Abstract

The flow structure in the aerated region of the roller generated by breaking waves remains a great challenge to study, with large quantities of entrained air and turbulence interactions making it very difficult to investigate in details. A number of analogies were proposed between breaking waves in deep or shallow water, tidal bores and hydraulic jumps. Many numerical models used to simulate waves in the surf zone do not implicitly simulate the breaking process of the waves, but are required to parameterise the wave-breaking effects, thus relying on experimental data. Analogies are also assumed to quantify the roller dynamics and the energy dissipation. The scope of this paper is to review the different analogies proposed in the literature and to discuss current practices. A thorough survey is offered and a discussion is developed an aimed at improving the use of possible breaking proxies. The most recent data are revisited and scrutinised for the use of most advanced numerical models to educe the surf zone hydrodynamics. In particular, the roller dynamics and geometrical characteristics are discussed. An open discussion is proposed to explore the actual practices and propose perspectives based on the most appropriate analogy, namely the tidal bore.

Depth‐integrated nonhydrostatic free‐surface flow modeling using weighted‐averaged equations

“…This wave breaking is satisfactorily reproduced by the VAM model without any empirical parametrization for wave breaking, like those used in Boussinesq‐type models. () At t ( g / h ) 1/2 = 30, 35, and 40, the VAM predictions are in good agreement with the experimental data during the run‐up process. From t ( g / h ) 1/2 = 45 to 60, a moving hydraulic jump is progressively formed, linked to the drawdown process.…”

Energy Dissipation in the Inner Surf Zone: New Insights From LiDAR‐Based Roller Geometry Measurements

“…This suggests that energy dissipation rates calculated with equation can vary by an order of magnitude depending on the choice of A , which likely leads to significant effect for the modeling of the incident wave energy flux through the whole surf zone. Similarly, although cross‐shore and temporal variations of ρ r are expected during the various breaking stages (e.g., see Blenkinsopp & Chaplin, ; Kimmoun & Branger, ; Rojas & Loewen, ), is the common choice in all the previous studies mentioned, which would appear to be a nonphysical choice given that this region is characterized by the fact that the flow is two phase (Lubin & Chanson, ).…”

CFD modeling of tidal bores: development and validation challenges

“…A tidal bore is technically a hydraulic jump in translation (CHANSON 2009). There are analogies between stationary hydraulic jumps, positive surges, compression waves and estuarine bores (tidal bores, tsunami bores) as discussed recently (WANG et al ,2017;LUBIN and CHANSON, 2017). In the present contribution, we wish to focus on tidal bore propagation in natural channel.…”

“…Several common features were observed. First, a tidal bore is a positive surge, a compression wave, and a hydraulic jump in translation (LIGHTHILL, 1978;LUBIN and CHANSON, 2017). It is a hydrodynamic shock, with no net mass flux, i.e.…”