Trying to setup a collapse of granular column proble

[akb63]

I am trying to create a column which starts collapsing as time progresses. For that I want to create a virtual wall to hold the column when the column bed created then suddenly i want to delete that virtual wall. Is there any command to create the virtual wall for such setup?

For example in liggghts the command to create virtual wall is fix wal11 all wall/gran model hertz tangential history primitive type 1 zplane 0.0

[PhasicFlow]

The solution is simple. Do your simulation with cylinder and put an actual wall in the middle of cylinder. do the packing phase. Suppose that you have done the packing up to time t = 1. Now do the following:

1. In the settingsDict, change the start time to 1.
2. In geometryDict, delete the dictionary of the middle plane wall (dont forget to save the file in the end).
3. execute the command, geometryPhasicFlow. This will create a geometry without middle wall.
4. run your solver to perform the rest of simulation.

I also have another idea for your case:

1. define two sizes of particles, say you want to perform simulation with 1-mm particles. two sizes would be 0.001 and 0.000999
2. perform packing up to t = 1 (or whatever that it requires).
3. In the settingsDict, change the start time to 1.
4. In the particlesDict, in the setFields dictionary, select particles in a half of the cylinder (in the selector dictionary) and set the shapeName to those selected particles to the name of the small particle.
5. run the command particlesPhasicFlow --setFields-only. This only applies the setFields section and changes the type of particles for you that are located in the half of cylinder.
6. run the simulation

[akb63]

I wanted to do this kind of problem(

). While creating the granular column of 0.2 m, 0.2 m, 0.1. I wanted to create a wall to restrict the particles in this rectangular domain and after sometime the restraining wall at 0.2 m will be removed and column starts collapsing. Kindly help me to setup such problem.

Thanks.

[PhasicFlow]

I understood your question and answered you. Take the first solution and apply it.

Do your simulation with cylinder and put an actual wall in the middle of this cuboid. Do the packing phase. Suppose that you have done the packing up to time t = 1. Now do the following:

1. In the settingsDict, change the start time to 1.
2. In geometryDict, delete the dictionary of the middle plane wall (dont forget to save the file in the end).
3. execute the command, geometryPhasicFlow. This will create a geometry without middle wall.
4. Now you are ready to execute the solver. Any CFD-DEM solver, that you want to use.

[PhasicFlow]

If you still have problem with this simulation, attach your simulation case setup files so I can check them.

[akb63]

my case file is attached here. I am trying to modify dam break case of example.

damBreak.zip