The objective of this link is to provide a resource for CFD developers to:
obtain different gas-liquid benchmark test cases for validation and verification,
verify related CFD models are implemented correctly.
This latter capability is made possible through benchmark cases. This site provides simple test cases and grids, along with sample results from experiments which are mainly reported in previous published works. All the test cases are prepared as standard cases for open-source code OpenFOAM-8. It can be run by the following command in the terminal:./Allrun
The site should also help CFD code users to understand and compare the predictions of a variety of models on the fundamental flow problems in the validation database. It also helps developers to disseminate new models to the CFD community.
It is anticipated that this word will be updated regularly as new models and/or verification/validation cases are incorporated and tested. If you have any questions or comments, please contact one of the authors: Dongyue Li (firstname.lastname@example.org)
1. Diaz et al. 2008
Features: This test case is a laboratory rectangle turbulent bubble column. The gas was injected in the middle of the bottom, which implies the geometry is quite symmetric. Nonetheless, it was also shown that the dynamic periodic liquid circulation can be founded in experiments. Simulations should be able to predict such periodic bubble plume with only the drag model. In addition, the authors also investigated the role of lift force and virtual mass force. The geometry is simple and settings are clear. This test case is suitable for investigate numerical algorithm. It should be noted here that the mean Sauter diameter data was also provided, although not in detail.
Keywords: Unsteady, Rectangle bubble column, Mean Sauter diameter, Bubble plume,
Features: This test case focuses on the unsteady 3D bubble column operated under high phase fration. Different swarm models were studied and a new swarm model was developed. The diameter of the bubble column ranges from 0.4m to 1m. Different superficial velocities from 0.03 m/s to 0.35 m/s were employed. This test case is suitable for investigate the swarm model correction based on different operating conditions.
Keywords: Unsteady, 3D bubble column, Swarm effect, High phase fraction,
Features: In the work of Lucas et al., bubbly flow in a high aspect ratio column (Column width ~ 0.05 m, Column height ~ 4 m) was investigated. Bubbles and liquid are injected from the bottom. They move upward and at a certain level a fully developed flow pattern is formed. In both experiments and simulations, a quite steady state can be reached at the top of the column. These bubbly flows are operated at relative low phase fraction (~ 3%). The most important feature of the test cases by Lucas et al. is that the momentum exchange interfacial terms play an important role. It was observed in the experiments that the small bubbles tend to move towards to wall. Therefore, a wall peak of the phase fraction should be predicted in simulations. It should be noted here that the lift force, wall lubrication force and turbulent dispersion force should be included.
Features: In the work of Yuan et al., an experimantal quasi-2D bubble column was investigated. In the simulations, 2D computational domain was employed. The bubbles are injected from the bottom of the column with different patterns. Overall 5 patterns were studied. Due to the high superficial velocity, simulations are highly transient. In this work, the QBMM was used to predict bubble diameter. However, the experimental diameter data was not reported. The bubble number density function was also reconstructed by EQMOM. It should be noted here that the experimental data reported in Yuan et al. comes from the PhD thesis of Harteveld, see ref (8) in Yuan et al.
Features: In the work of Schafer et al., a 3D transient bubble column was studied by experiments and simulations. The geometry used in this work is similar with that used by Diaz et al. The unique feature of this work is that the bubble orientation angle data was provided. It can be used as a benchmark test case for multiphase DNS. Besides that, the bubble diameter NDF was also provided both in experiments and simulations. The so-called SQMOM, as a kind of QBMM, was used predict the bubble NDF at different locations and it was compared with experiments.
Keywords: Unsteady, 3D simulation, NDF reconstruction, SQMOM, Bubble orientation angle
Features: In the work of Li et al., three 3D transient bubble column was studied to verify the algorithm. One of test case was reported in Diaz et al. The other one consists of a similar partially aerated rectangle bubble column which was investigated experimentally by Becker et al. in 1994. The left one is an airlift bubble column investigated by Mandalahalli et al. Li et al. developed a new algorithm which is much faster than the traditional Eulerian-Eulerian method and used it to simulate three different bubbly flows as mentioned above. Only drag force needs to be included (the last airlift bubble column also needs the turbulent dispersion force). These test cases are suitable to validate new developed algorithms.
Keywords: Unsteady, 3D simulation, Airlift bubble column, Particlly aerated
Features: In the work of Besbes et al., a needle sparger rectangular bubble column operated at low flow rates was investigated using PIV measurements and Eulerian-Lagrangian simulations. Time-averaged liquid velocity fields from PIV measurements for different flow rate were provided. Snapshots of PIV and Eulerian-Lagrangian simulation of oscillating bubble plume were also supplied. Due to the small flow rate and the usage of a needle sparger, the diameter of bubbles is very homogeneous. The oscillatory movement of bubble plume, as that observed in Diaz et al., was also formed for slightly large flow rate (Q = 0.2 l/min).
Features: In this work, a rectangle laboratory bubble column was used to study the bubble flow with reactions. A pseudo-2D geometry is chosen to enable visualization of the flow structures by CCD camera and PIV. Lagrangian simulations were also launched. Averaged velocities, bubble plume period, gas holdup and global mean Sauter diameter were also compared with experiments. The species's concentration and Ph value were also provided.
Keywords: Reaction bubble column, Mass transfer, mean Sauter diameter
Features: In this work, the authors employ PIV technique to study the liquid phase flow driven by a chain of air bubbles in a rectangular bubble column. The flow rate is very low that each bubble move upward separately by buoyancy force. Not only water, but also the glycerin solution with high viscosity was studied to understand the liquid flow structure. Bubble terminal velocity and shape were also provided.
While in geometry the word barycenter is a synonym for centroid, in astrophysics and astronomy, the barycenter is the center of mass of two or more bodies that orbit each other. In physics, the center of mass is the arithmetic mean of all points weighted by the local density or specific weight. If a physical object has uniform density, its center of mass is the same as the centroid of its shape.