Abstract:

Interaction between the wind-driven shear and the wave-induced Stokes drift in the upper ocean leads to Langmuir circulation consisting of wind-aligned counter-rotating vortices. In inner-shelf regions up to 30 meters in depth undergoing strong wind and wave forcing during the passage of storms, Langmuir cells have been observed reaching the bottom of the water column while increasing in intensity and coherency (Gargett and Wells, 2007; Gargett and Savidge, 2020). These cells have been denoted as Langmuir supercells (LS) due to their significant impact on the turbulence dynamics throughout the entire water column and their distinct structure compared to ordinary Langmuir circulation in the upper ocean mixed layer. A Reynolds-averaged Eulerian formulation is developed resolving LS as a secondary component to the wind-driven mean shear current, and this formulation is combined with Lagrangian particle tracking to investigate oil droplet entrainment induced by the LS. The efficiency of the cells in mixing oil droplets of 500 microns throughout the water column is compared to wind-driven flow with 0.025 and 0.1 N/m^-2 forces. Characteristic timescales of the initial accumulation of oil droplets in submerged Stommel retention zones and the subsequent homogenization of the droplets about these zones are established. The dataset includes modeled particle trajectories for cases with a Langmuir number of 0.7 and wavelength to depth ratios of 4/3 and 6 and a y-z slice of the velocity field at x position 0.785398 at the final step of the model run. Also included are particle trajectory animations for wavelength/depth = 6, Langmuir number 0.5, and two different wind regimes. This dataset supports the publication: Perez, Anthony J., Fangda Cui, Juan Peñaloza-Gutierrez, Seyed Zeidi, Nityanand Sinha, Michel Boufadel, Carlowen A. Smith, David W. Murphy, and Andrés E. Tejada-Martínez. (2021). Simulation of vertical dispersion of oil droplets by Langmuir supercells through a Reynolds-averaged Eulerian formulation combined with Lagrangian particle tracking. Ocean Engineering, 235, 109043. doi:10.1016/j.oceaneng.2021.109043.

Suggested Citation:

Perez, Anthony J., Fangda Cui, Seyed Zeidi, Nityanand Sinha, Michel Boufadel, David W. Murphy, and Andrés E. Tejada-Martínez. 2021. Dataset for: Simulation of vertical dispersion of oil droplets by Langmuir supercells through a Reynolds-averaged Eulerian formulation combined with Lagrangian particle tracking. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/JXE8ZBNV

Publications:

Perez, A. J., Cui, F., Peñaloza-Gutierrez, J., Zeidi, S., Sinha, N., Boufadel, M., … Tejada-Martínez, A. E. (2021). Simulation of vertical dispersion of oil droplets by Langmuir supercells through a Reynolds-averaged Eulerian formulation combined with Lagrangian particle tracking. Ocean Engineering, 235, 109043. doi:10.1016/j.oceaneng.2021.109043

Purpose:

The purpose is to study the transport of oil droplets within Langmuir supercells (LS) generated in the nearshore region. With different wind speeds, LS have different hydrodynamics, and hence the transport of oil droplets within them will be distinct.

Data Parameters and Units:

Time [s], particle ID, x position [m], y position [m], z position [m], x velocity [m/s], y velocity [m/s], z velocity [m/s]; x position, y position, z position, turbulent energy dissipation, turbulent length scale, x velocity [m/s], y velocity [m/s], turbulent kinetic energy, z velocity [m/s], and turbulent time scale [s].

Methods:

Hydrodynamics of the Langmuir cell was reproduced using a commercial computational fluid dynamic code ANSYS FLUENT. The transport of oil droplets was simulated using our in-house Lagrangian particle tracking code NEMO3D. The model had a rigid lid, no-slip bottom, and periodic horizontal extent with domain crosswind 94.2 m, downwind 62.8 m, vertical 15m. Please see the associated publication, Perez et al., 2021 for more details.

Provenance and Historical References:

Garett, A. E., & Wells, J. R. (2007). Langmuir turbulence in shallow water. Part 1. Observations. Journal of Fluid Mechanics, 576, 27–61. doi:10.1017/s0022112006004575 Gargett, A. E., & Savidge, D. K. (2020). Winds, Waves, and Turbulence on a Shallow Continental Shelf during Passage of a Tropical Storm. Journal of Physical Oceanography, 50(5), 1341–1364. doi:10.1175/jpo-d-20-0024.1

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