@misc{10481/85294,
year = {2023},
month = {9},
url = {https://hdl.handle.net/10481/85294},
abstract = {An experimental investigation of two-dimensional dispersively focused laboratory
breaking waves is presented. We describe the bandwidth effect on breaking wave
energetics, including spectral energy evolution, characteristic group velocity, energy
dissipation and its rate, and breaking strength parameter, b. To evaluate the role of
bandwidth, three definitions of wave group steepness are adopted where Ss and Sn are
bandwidth-dependent and Sp remains constant when bandwidth is changed. Our data show
two regimes of spectral energy evolution in breaking wave groups, with both regimes
bandwidth-dependent: energy dissipation and gain occur at f > 0.95fp ( fp is the peak
frequency) and f < 0.95fp, respectively. The characteristic group velocity, which is used
in energy dissipation calculations, increases by up to 7% after wave breaking, being larger
for higher bandwidth breaking waves. An unambiguous bandwidth dependence is found
between Sp and both the fractional and absolute wave energy dissipation. Wave groups of
larger bandwidth break at a lower value of Sp and consequently lose relatively more energy.
The energy dissipation rate depends on the breaking duration which itself is bandwidth
dependent. Consequently, no clear bandwidth effect is observed in energy dissipation rate
when compared with either Sp or Ss. However, there is a systematic bandwidth dependence
in the variation of b when parameterised in terms of Sp, with their relationship becoming
increasingly nonlinear as bandwidth increases. When parameterised with Ss, b shows
a markedly reduced bandwidth dependence. Finally, the numerical breaking onset and
relationship between b and Ss in the numerical study of Derakhti & Kirby (J. Fluid Mech.,
vol. 790, 2016, pp. 553–581) is validated experimentally},
organization = {National Science Foundation (grant number
OCE-1434866)},
organization = {Royal
Society Shooter International Fellowship and a NERC Standard Grant (grant number NE/T000309/1)},
organization = {NERC (grant number NE/T000309/1)},
keywords = {Wave breaking},
keywords = {Surface gravity waves},
keywords = {Air/sea interactions},
title = {The influence of bandwidth on the energetics of intermediate to deep water laboratory breaking waves},
doi = {10.1017/jfm.2023.645},
author = {Cao, Rui and Padilla de la Torre, Enrique and Callaghan, A.H.},
}