Yade

questions about boundary condition of PFV model

Asked by bin deng

Dear all,
     I would like to create periodic and flexible( mentioned in paper[1] )boundary condition in DEM-PFV model, but I don't know how to set flexible boundary condition. And I want to know how to set different boundary conditions on different faces. As far as I know, when flow.bndCondValue=[0,0,0,1,0,0] is set, only the upper surface can impose the pressure and the others is impermeable boundary conditions. Similarly, If use PeriodicFlowEngine to introduce fluid into the system, how to set different boundary conditions.
    So, I want to ask two questions.
    1. does flexible boundary condition exist? if does, how to set?
    2. how to set different boundary conditions on different faces, especially periodic and flexible boundary.

    Thank you for any suggestions.

Deng

[1]Catalano E. A pore–scale coupled hydromechanical model for biphasic granular media. Application to granular sediment hydrodynamics[D]. PhD thesis, Université de Grenoble, 2012.

Question information

Language:
English Edit question
Status:
Solved
For:
Yade Edit question
Assignee:
No assignee Edit question
Solved by:
bin deng
Solved:
Last query:
Last reply:
Revision history for this message
bin deng (dengbintju) said : 		#1

I also want to add some information and questions here.
I'm trying to simulate the liquefaction of the soil under the action of upper wave pressure, but the problem is that the pressure can not be dissipated reasonably in the soil when flow.bndCondValue=[0,0,0,1,0,0] is set. I need the boundary condition that the flow velocity gradient is zero rather than no-flux. But I don't know how to set. _____Q1
Or, I don't want to simulate so large area soil and just take a part of soil to simulate. How should I to set the boundary condition.____Q2

Thank you for any suggestions.
Deng

Revision history for this message
Bruno Chareyre (bruno-chareyre) said : 		#2

Hello,
The current code will not handle flexible boundaries for the fluid part.
For periodicity the question is a bit unclear. A periodic problem has no boundaries, hence no "faces".
I'm not sure what you mean by "flow velocity gradient is zero rather than no-flux", could you elaborate?
Bruno

Revision history for this message
bin deng (dengbintju) said : 		#3

Dear Bruno
Thanks for your reply.
In fact, I want to simulate a test of in-site or experiment, but its area is too large so that I have to select a part of area to simulate. So, I don't know how to set boundary conditions in my script.
Thank you for your reply again.

Beng

Revision history for this message
Bruno Chareyre (bruno-chareyre) said : 		#4

>I want to simulate a test of in-site or experiment, but its area is too large so that I have to select a part of area to simulate

This is a well identified issue which is completely independent of yade.
We can answer (hopefully) the questions like "how to impose this particular boundary condition?".
Which boundary condition is best suited for model reduction is really problem dependent and should be based on physical considerations, not technicalities of a computer code. I am not personally expert of this second question, and the description of the problem is too vague to answer anyway.

Bruno

Revision history for this message
bin deng (dengbintju) said : 		#5

Thanks Bruno Chareyre, that solved my question.