@李东岳 东岳老师，我在dynamicMeshDict里设置了constrints和restraints两个条目，控制圆柱仅在y方向移动，不转动，如下：

constraints { yLine { sixDoFRigidBodyMotionConstraint line; centreOfRotation (0 0 0.5); direction (0 1 0); } noRotation { sixDoFRigidBodyMotionConstraint orientation; } } restraints { verticalSpring { sixDoFRigidBodyMotionRestraint linearSpring; anchor (0 0 0.5); refAttachmentPt (0 0 0.5); stiffness 2.1055; damping 0; restLength 0; } }

不知道您说的是不是这个意思？

@李东岳 感谢李老师百忙之中指点！这么来看correction(fvm::ddt(p))就代表前后时间步压力差值的时间变化率啦

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 (li.dy@dyfluid.com)

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,

Reference: Díaz et al. "Numerical simulation of the gas–liquid flow in a laboratory scale bubble column: influence of bubble size distribution and non-drag forces." Chemical Engineering Journal 139.2 (2008): 363-379.

bubbleFlow_diaz.jpg

2. Gemello et al. 2018

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,

Reference: Gemello et al. "CFD-based scale-up of hydrodynamics and mixing in bubble columns." Chemical Engineering Research and Design 136 (2018): 846-858.

bubbleFlow_Gemello.jpg

3. Lucas et al. 2007

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.

Keywords: Steady, Bubbly flow, Lift force, Wall forces

Reference: Lucas et al., "Use of models for lift, wall and turbulent dispersion forces acting on bubbles for poly-disperse flows." Chemical Engineering Science 62.15 (2007): 4146-4157.

bubbleFlow_Lucas.jpg

4. Yuan et al. 2014

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.

Keywords: Unsteady, Bubble column, 2D simulation

Reference: Yuan et al., "An extended quadrature‐based mass‐velocity moment model for polydisperse bubbly flows." The Canadian Journal of Chemical Engineering 92.12 (2014): 2053-2066.

bubbleFlow_Yuan.jpg

5. Schafer et al. 2019

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

Reference: Schäfer et al., "Experimental investigation of local bubble properties: Comparison to the sectional quadrature method of moments." AIChE Journal 65.10 (2019): e16694.

bubbleFlow_Schafer.jpg

6. Li et al. 2021

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

Reference: Li et al. "QEEFoam: A Quasi-Eulerian-Eulerian model for polydisperse turbulent gas-liquid flows. Implementation in OpenFOAM, verification and validation." International Journal of Multiphase Flow 136 (2021): 103544.

bubbleFlow_Li.jpg

7. Besbes et al. 2015

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).

Keywords: Needle sparger, Eulerian-Largrangian, PIV

Reference: Besbes et al., "PIV measurements and Eulerian–Lagrangian simulations of the unsteady gas–liquid flow in a needle sparger rectangular bubble column." Chemical Engineering Science 126 (2015): 560-572.

bubbleFlow_Besbes.jpg

8. Darmana et al. 2007

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

Reference: Darmana et al. "Detailed modelling of hydrodynamics, mass transfer and chemical reactions in a bubble column using a discrete bubble model: Chemisorption of CO2 into NaOH solution, numerical and experimental study." Chemical Engineering Science 62.9 (2007): 2556-2575.

bubbleFlow_Darmana.jpg

9. Besbes et al. 2020

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.

Keywords: PIV, Bubble driven flow, High viscosity

Reference: Besbes et al., "Effect of bubble plume on liquid phase flow structures using PIV." Particulate Science and Technology 38.8 (2020): 963-972.

bubbleFlow_Besbes2.jpg

Test Case Diaz et al. 2004 Gemello et al. 2018 Yuan et al. 2014 Lucas et al. 2007 Schafer et al. 2019 Li et al. 2021 Besbes et al. 2015 Darmana et al. 2007 Besbes et al. 2020 Experiments - - - - - - - - - Global holdup - - - - - - - - - Local holdup - - - - - - - - - Liquid velocity - - - - - - - - - Wall effects - - - - - - - - - Turbulent kinetic energy - - - - - - - - - Turbulent dissipation rate - - - - - - - - - Global Sauter diameter - - - - - - - - - Local diameter distribution - - - - - - - - - Local Sauter diameter - - - - - - - - - Reactions - - - - - - - - - Heat transfer - - - - - - - - -

各位大佬好，想请教一下，我想显示一个密度、体积不断变化的物体的质量，请问大家有什么好办法吗？

屏幕截图 2021-06-05 161820.png openfoam自带案例interPhaseChangeFoam求解器下的cavitatingBullet，该图为我跑完0.05s后的水相分布，和0s时没啥变化,请问我哪里错了吗？

@李东岳 感谢李老师回复，我先试下

@李东岳

我用下面的命令解决了 ，具体为啥不清楚..

sudo ntfsfix /dev/sdXY

https://askubuntu.com/questions/145902/unable-to-mount-windows-ntfs-filesystem-due-to-hibernation

@李东岳 好的李老师，我明白了，特别感谢您！！

@李东岳 谢谢老师的回复！

@鲸落 其实也不是只显示一层。我想你跟我当时一样，感觉摄入粒子很多，其实由于体积太小，所占的相分数其实不大。那么最后就会只有一层。如果有很多粒子的话，最后会形成很多层，因为只要满足你预设的最大相分数，它就不会再允许粒子进入，那么就会在其上方的网格中开始堆积。

@tens 学到了，感谢老师的指点！:chitang:

@hongjiewang http://dyfluid.com/rhoPimpleFoam.html 这个你看过没老铁

@李东岳 在 请问如何把pbm耦合气液多相流算例中？ 中说：

？

博士论文方向是做搅拌釜内的气液两相流，由于版权问题只能用openfoam来做了，由于课题组之前在fluent有一定pbm基础，所以还是想用pbm来模拟，具体方向主要是反应器的设计的实验研究，把实验结果通过模拟对比一下，不是openfoam的攻坚:chouchou: 所以暂时还是追求着能用就行的原则来，后面可能对模拟精度要求高了，就要自己深入研究算法了:135:

@李东岳 好的，谢谢李老师

@zhouxu 如果是h的传输方程，就不能有calculated边界条件。你可以把你的温度边界赋值给h，类似;

volScalarField h ( ( ). mesh, T.boundaryField().types() );

@bestucan 太感谢了，非常有针对性的网址，谢谢！

https://www.cfd-online.com/Forums/openfoam-solving/136437-why-icofsifoam-considered-deprecated.html

官方没做，然后各做各的，互不相通，版本就多了。

还有interfsifoam呢
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2009/KarlJacobMaus/FSI_with_OpenFOAM_unpeered.pdf

http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2016/MinghaoLi/Minghao_report.pdf

第二个问题，怎么总感觉有人问过？不是你又问了一遍吧:chigua:

权限不够是下载的源代码权限设置有问题。用chmod修改权限。

各位大佬，如果我想在openfoam里自己新建个固体结构，由散点组成，上面的物理量要插值给附近的流体cell，但是并行时候，因为docompose了计算域，会可能出现一个散点周围的流体cell不在一个domain，那这种情况怎么处理呢？

@hotairballon1997
kinematicParcel中先看move部分，

初始化各个参数，计算lagrangian 步长。 更新参数，setCellValues，计算dispersion，然后calc方程 在calcVelocity中得到新parcel速度，新parcel速度calcVelocity部分中计算parcel受力得到新的parcel速度，返回到calc中，然后在calc中，根据 1-way 2-way 计算parcel是否对流场产生影响 然后返回到move中。。

https://openfoam.top/sprayVelocity/

所以Q1 在你不说你的模拟是1way 还是2way 是无法解释的
Q2 在上面的链接一定程度上可以解释一些

Explicit contribution, Su specified as a force Implicit coefficient, Sp specified as force/velocity