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-   -   Escape mode in lagrangian (http://www.cfd-online.com/Forums/star-ccm/111944-escape-mode-lagrangian.html)

siara817 January 18, 2013 08:18

Escape mode in lagrangian
 
Hello every body,
I am using lagrangian multiphase model to simulate particles in indoor condition.
the problem is that when I activate escape condition for any boundary the lagrangian does not work any more. Do you know what is the problem?
:confused:

abdul099 January 18, 2013 16:27

Pretty unlikely, since the information you've given here is ... a little low. Could you please describe a bit more what your issue is? Especially what "does not work anymore" should mean? Steady, Unsteady? Other physics? Etc...

siara817 January 21, 2013 05:39

Dear Abdul,

I use steady simulation, K-epsilon, 3 dimensional. I want to remove from the system the particles that touch floor ( because they settle down on the floor). There is an option to use escape mode for the lagrangian phase, but when I activate escape mode, the lagrangian solver stops and iterations continue without giving any data for lagrangian. However I found another way to solve it. I specify the method to be Rebound. Then I put the coefficient to the amount Zero.

siara817 January 21, 2013 05:44

Dear Abdul,

I have another question.
I have 20 parcels for 10000 particles. After finishing the iterations of Lagrangian solver Usually I have some parcels that reach the maximum sub-steps. Is the result reliable?
The way of solving this problem is to increase the maximum number of sub-steps, but it will take a lot of time and the track file will be so big.
Thank you in advance

abdul099 January 21, 2013 14:18

As always this depends on your specific case and your requirements in terms of accuracy, hence it's pretty hard to make any assumptions.

But in general I can tell you that you can't always avoid big files or long computing times just by saying "it takes too long for me and the files are so big". I mean, I know that you would appreciate when it would be much faster, as nearly anybody else. But some kind of simulation just takes some effort.


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