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November 19, 2014, 14:54 |
VOF BC not compatible?
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#1 |
New Member
Join Date: Jun 2014
Posts: 29
Rep Power: 12 |
Hi everyone!
I am simulating a free falling film of water, but Fluent does not agree with my settings. I am using VOF with implicit volume fraction scheme, open channel flow with implicit body force. I use mass-flow inlet with only water, and the outlet at outflow. Edit: By testing switching off open channel flow I no longer get the warning. However, the fluent theory manual states that I in fact can use mass-inlet/outflow with open channel flow enabled. Please help? |
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November 21, 2014, 15:44 |
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#2 |
Senior Member
B_Kia
Join Date: May 2014
Location: Ir
Posts: 123
Rep Power: 12 |
hi
use mass flow inlet as inlet boundry condition and pressure outlet as outlet set the mass flow of air at inlet zero |
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November 21, 2014, 18:36 |
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#3 |
Senior Member
Stuart Buckingham
Join Date: May 2010
Location: United Kingdom
Posts: 267
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Hi Herrolsen,
It sounds like you have a supercriticality in your simulation, so the free surface heights at both the top and bottom reservoirs will not be implicit in the problem definition, and therefore you must specify both boundary conditions. The actual condition depends on the problem. If you're simulating a fixed mass flow condition, obviously use that particular bc, but if you are simulating near-infinate length reservoirs, then pressure bcs with hydrostatic profiles are more applicable. Good Luck Stu |
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November 24, 2014, 13:14 |
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#4 |
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November 24, 2014, 14:08 |
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#5 | |
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Quote:
I am simulating a fixed mass flow condition, so that seemed like the most appropriate BC to use. Just found it weird that the manual and program contradicts itself. Then I'm blank again, anyone have an idea of why I can't use these settings together? |
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November 24, 2014, 23:31 |
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#6 |
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November 25, 2014, 11:56 |
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#7 |
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B_Kia
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Location: Ir
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November 25, 2014, 11:58 |
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#8 |
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Thank you very much! It seems to be stable now. I still don't understand why I cant use outflow though :P
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November 26, 2014, 04:02 |
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#9 |
Senior Member
B_Kia
Join Date: May 2014
Location: Ir
Posts: 123
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you can locate outflow boundry condition where the flow is fully developed otherwise the result will be wrong , by the way is this your university project ? where do u study ?
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November 26, 2014, 13:51 |
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#10 |
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That explains why it was unstable, thanks again HyperNova! Yes it is I study in Sweden!
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November 26, 2014, 16:53 |
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#11 |
Senior Member
B_Kia
Join Date: May 2014
Location: Ir
Posts: 123
Rep Power: 12 |
your welcome my friend ,by the way i study in iran, MSc in hydraulics engineering , i hope you more success and luck , forgive my bad english
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boundary conditions, volume of fluid |
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