Abstract:

The dataset contains the results of approximately fifty cases generated by an Eulerian-Lagrangian Large Eddy Simulation (LES). Computations were performed with OpenFOAM (Version 6, https://openfoam.org). Parameters varied include bubble diameter, bubble source area, buoyancy frequency, and buoyancy flux. Results include trap height, peel height, density field represented by the salinity concentration (1% salinity concentration = (1+1%)*1000 = 1010 kg/m^3), and the dye concentration as a percentage of the initial, maximum value. Two example flow fields from Case 10-4 are included in the dataset: the three-dimensional velocity and tracer fields and a temporally and circumferentially averaged two-dimensional slice of the velocity and tracer fields. Missing trap/peel heights in the data files are those not able to be distinguished in the dyed bubble/seawater plume mixture.

Suggested Citation:

Zhou, Guangzhao. 2020. Large Eddy Simulation investigation of the influence of bubble sources on plume trap/peel heights in a stratified environment. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/ZJE9W16W

Publications:

Zhou, G. (2020). Computational Study of the Source-Area Effect for Bubble Plumes in Stratified Environments. Journal of Hydraulic Engineering, 146(6), 04020039. doi:10.1061/(asce)hy.1943-7900.0001759

Purpose:

The data were generated to study the influence of the bubble source area on the plume trap height and peel height for bubble plumes in stratified environments.

Data Parameters and Units:

The file "table of cases.csv": Case #, bubble diameter [mm], bubble slip velocity [cm/s], bubble source radius [cm], buoyancy frequency [1/s], buoyancy flux[1e^-6 m^4/s^3], trap height [cm], peel height [cm]. The file "flow_field.csv": dye concentration (relative to initial concentration [%]), salinity concentration (percentage of density variation relative to pure water [%]), water velocity (x component) [m/s], water velocity (y component) [m/s], water velocity (z component) [m/s], water volume fraction (of gas bubble/water mixture [%]), turbulent viscosity [m^2/s], x [m], y [m], z [m]. The file "averaged_field.csv": dye concentration (relative to initial concentration [%]), salinity concentration (percentage of density variation relative to pure water [%]), water velocity (x component) [m/s], water velocity (y component) [m/s], water velocity (z component) [m/s], x [m], y [m], z [m].

Methods:

The Smagorinsky turbulence model was used, along with the WenYu model for the drag force and Saffman-Mel model for the lift force of the bubbles. The coefficient for the virtual-mass force was set to 0.5. The model domain was rectangular, with dimensions of 1.6 m x 1.6m x 2.1 m, containing 128 x 128 x 160 mesh cells. The circular bubble source was centered on the bottom wall, and bubbles with zero initial velocity are randomly seeded from 1880 points and distributed as Lagrangian particles throughout the source area. To visualize the flow field and allow determination of the trap and peel heights, the dye is released along with the bubbles, setting a constant concentration in a cylinder slightly larger than the bubble source. The size of the model domain is large enough that the dye does not reach the side walls within the 500 second simulation time. Slip boundary conditions are applied at the bottom and sidewalls to minimize the effect of the solid boundaries. The top boundary is assumed to be open to the atmosphere with constant pressure. Liquid and bubble velocities are unconstrained at the surface, so bubbles are allowed to leave the domain through the top surface. No free surface was simulated. The obtained trap and peel heights are well below the top boundary and are not affected by it.

Individual Files: