TY - JOUR
T1 - High-resolution direct simulation of deep water breaking waves
T2 - Transition to turbulence, bubbles and droplets production
AU - Mostert, W.
AU - Popinet, S.
AU - Deike, L.
N1 - Funding Information:
This work was supported by the National Science Foundation (Physical Oceanography) under grant no. 1849762 to L.D., and the Cooperative Institute for Earth System modelling between Princeton and the Geophysical Fluid Dynamics Laboratory (GFDL) NOAA. Computations were partially performed using allocation TG-OCE180010 to W.M. from the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by NSF grant no. ACI-1053575, and the HPC resources of CINES and TGCC under the allocations 2019- A0072B07760, 2020-A0092B07760 granted by GENCI, and from the Jean Zay Grand Challenge allocation from IDRIS. Computations were also performed on resources managed and supported by Princeton Research Computing, a consortium of groups including the Princeton Institute for Computational Science and Engineering, and the Office of Information Technology's High Performance Computing Center and Visualization Laboratory at Princeton University.
Publisher Copyright:
©
PY - 2022/7/10
Y1 - 2022/7/10
N2 - We present high-resolution three-dimensional (3-D) direct numerical simulations of breaking waves solving for the two-phase Navier-Stokes equations. We investigate the role of the Reynolds number (Re, wave inertia relative to viscous effects) and Bond number (Bo, wave scale over the capillary length) on the energy, bubble and droplet statistics of strong plunging breakers. We explore the asymptotic regimes at high Re and Bo, and compare with laboratory breaking waves. Energetically, the breaking wave transitions from laminar to 3-D turbulent flow on a time scale that depends on the turbulent Re up to a limiting value, consistent with the mixing transition in other canonical turbulent flows. We characterize the role of capillary effects on the impacting jet and ingested main cavity shape and subsequent fragmentation process, and extend the buoyant-energetic scaling from Deike et al. (J. Fluid Mech., vol. 801, 2016, pp. 91-129) to account for the cavity shape and its scale separation from the Hinze scale. We confirm two regimes in the bubble size distribution, for r_H$]]>, and for <![CDATA[$r. Bubbles are resolved up to one order of magnitude below, and we observe a good collapse of the numerical data compared to laboratory breaking waves (Deane & Stokes, Nature, vol. 418 (6900), 2002, pp. 839-844). We resolve droplet statistics at high Bo in good agreement with recent experiments (Erinin et al., Geophys. Res. Lett., vol. 46 (14), 2019, pp. 8244-8251), with a distribution shape close to. The evolution of the droplet statistics appears controlled by the details of the impact process and subsequent splash-up. We discuss velocity distributions for the droplets, finding ejection velocities up to four times the phase speed of the wave, which are produced during the most intense splashing events of the breaking process.
AB - We present high-resolution three-dimensional (3-D) direct numerical simulations of breaking waves solving for the two-phase Navier-Stokes equations. We investigate the role of the Reynolds number (Re, wave inertia relative to viscous effects) and Bond number (Bo, wave scale over the capillary length) on the energy, bubble and droplet statistics of strong plunging breakers. We explore the asymptotic regimes at high Re and Bo, and compare with laboratory breaking waves. Energetically, the breaking wave transitions from laminar to 3-D turbulent flow on a time scale that depends on the turbulent Re up to a limiting value, consistent with the mixing transition in other canonical turbulent flows. We characterize the role of capillary effects on the impacting jet and ingested main cavity shape and subsequent fragmentation process, and extend the buoyant-energetic scaling from Deike et al. (J. Fluid Mech., vol. 801, 2016, pp. 91-129) to account for the cavity shape and its scale separation from the Hinze scale. We confirm two regimes in the bubble size distribution, for r_H$]]>, and for <![CDATA[$r. Bubbles are resolved up to one order of magnitude below, and we observe a good collapse of the numerical data compared to laboratory breaking waves (Deane & Stokes, Nature, vol. 418 (6900), 2002, pp. 839-844). We resolve droplet statistics at high Bo in good agreement with recent experiments (Erinin et al., Geophys. Res. Lett., vol. 46 (14), 2019, pp. 8244-8251), with a distribution shape close to. The evolution of the droplet statistics appears controlled by the details of the impact process and subsequent splash-up. We discuss velocity distributions for the droplets, finding ejection velocities up to four times the phase speed of the wave, which are produced during the most intense splashing events of the breaking process.
KW - Key words air/sea interactions
KW - multiphase flow
KW - wave breaking
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U2 - 10.1017/jfm.2022.330
DO - 10.1017/jfm.2022.330
M3 - Article
AN - SCOPUS:85131682514
SN - 0022-1120
VL - 942
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
M1 - A27
ER -