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update the pyhsicaltimestep during a steady-state-run |
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April 3, 2009, 09:18 |
update the pyhsicaltimestep during a steady-state-run
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#1 |
Senior Member
Matthias Voß
Join Date: Mar 2009
Location: Berlin, Germany
Posts: 449
Rep Power: 20 |
hey,
i am doing a mesh study and i am facing really slow convergence within the highest/finest mesh . So i could increase my timestep. According to the other runs on the coarser meshes i know that i can increase my phsyical timestep bit by bit. So i linked the physicaltimestep with an expression,like: "Timestep*Factor(CITERN)" to increase it depending on my iterationnumber. Tried it with the AutoTimeScale--> No problem. Updating the value means updating the factor means new timescale. But with PhysicalTimeScale the solver doesn't update the value for the timescale, so my function isn't working. Any idea how i can force the solver to update the value for the physical timescale automatically? Maybe smth. like an ExpertOption. Best regards, neewbie |
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April 3, 2009, 09:27 |
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#2 |
New Member
Martijn
Join Date: Mar 2009
Posts: 14
Rep Power: 17 |
I think this has to be done in Fortran. Probably in a similar way as described in "Junction Box Example 3: Timestep Control" in the help function of CFX-11.
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April 6, 2009, 01:09 |
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#3 |
Member
^_^
Join Date: Mar 2009
Posts: 36
Rep Power: 17 |
Em... It confused me.
For steady-state simulation, why does time step need to be defined in CFX? |
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April 6, 2009, 02:48 |
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#4 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,871
Rep Power: 144 |
Hi:
neewbie - your CEL is almost right. The variable name is "citern" in lower case. It is case sensitive. Look in the documentation for the exact naming of variables. Martijn - No need for fortran. CEL should be fine. Jasmine - CFX uses a timestep to advance the simulation, even in a steady state simulation. Read the documentation on this or do a search on past posts on this issue. Glenn Horrocks |
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April 6, 2009, 04:08 |
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#5 |
Senior Member
Matthias Voß
Join Date: Mar 2009
Location: Berlin, Germany
Posts: 449
Rep Power: 20 |
hi,
thanks for the response. I used the capital letters only for entering the post... in the expression i wrote "citern". Btw. the expression did well with the AutoTimeScale but not with the Physical... which is not loose because why should the solver update a value which is ought to be fixed over the run. Any further ideas? neewbie |
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