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April 8, 2010, 05:41 |
need help about UDS & VOF
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#1 |
New Member
mengyue
Join Date: Sep 2009
Posts: 17
Rep Power: 16 |
hi guys, i am simulating a system, the fluid involved in this system is water,water vapor and air, because of gradient of vapor mass fraction, there exists phase change.
i don't plan to use the species model available in FLUENT, in my model, i define there phases, which are water,vapor(phase-3) and air, and also, i introduce a UDS to model the diffusion of vapor in the air, the scalar is vapor mass fraction, is that right? I define the uds for phase-3, and i think i need define vapor/air diffusivity for this uds. but now i am confused with it. in the material pannel, each material has a "UDS Diffusivity", and which one i should introduce my udf for diffusivity? when i introduce udf to vapor, there are some error tips in FLUENT: Error: FLUENT received fatal signal (ACCESS_VIOLATION) 1. Note exact events leading to error. 2. Save case/data under new name. 3. Exit program and restart to continue. 4. Report error to your distributor. Error Object: () but when i define the same udf for other materials(air and water), there are not errors. Can someone tell me the reason... i think my udf should define for vapor, not the other materials... Regards! PS:the code is: DEFINE_DIFFUSIVITY(diffusivity, cell, third, i) { Thread *mix_th, *sec_th; real diff; real v; mix_th = THREAD_SUPER_THREAD(third); sec_th = THREAD_SUB_THREAD(mix_th, 1); if ((C_VOF(cell, sec_th)==1)) diff = 0.0; else diff = 3.02761*pow(10.0,-5.0)*C_MU_EFF(cell, mix_th); return diff; } |
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April 8, 2010, 08:48 |
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#2 |
New Member
mengyue
Join Date: Sep 2009
Posts: 17
Rep Power: 16 |
Dose anyone help me? thanks...and where is sega?
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April 9, 2010, 00:09 |
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#3 |
New Member
mengyue
Join Date: Sep 2009
Posts: 17
Rep Power: 16 |
Dose anyone help me? Thanks....
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April 9, 2010, 06:39 |
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#4 |
Senior Member
Sebastian Gatzka
Join Date: Mar 2009
Location: Frankfurt, Germany
Posts: 729
Rep Power: 20 |
sega is here!
But I think I'm not use here ...
__________________
Schrödingers wife: "What did you do to the cat? It's half dead!" |
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April 13, 2010, 21:44 |
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#5 |
New Member
mengyue
Join Date: Sep 2009
Posts: 17
Rep Power: 16 |
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April 12, 2012, 09:59 |
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#6 |
New Member
Igor
Join Date: Mar 2012
Posts: 13
Rep Power: 14 |
I solved such problem by this way:
1. Make UDM containing the data gotten via C_VOF. Simle cycle C_UDMI(...)=C_VOF(...) 2. Remove C_VOF(...) from DEFINE_DIFFUSIVITY 3. Use data from UDM in DEFINE_DIFFUSIVITY. It seems to me - this error appears in some cases when macros C_VOF try to work. For example in solid area. Best regards... |
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February 7, 2014, 09:51 |
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#7 |
Senior Member
Join Date: May 2011
Posts: 231
Rep Power: 15 |
hi,
did you manage to solve the problem...I have the same problem as you. thanks for your help in advance! |
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February 7, 2014, 17:40 |
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#8 |
New Member
Igor
Join Date: Mar 2012
Posts: 13
Rep Power: 14 |
I didn't try to do smth more exept described above method - this method works.
May be Fluent 15 is better? Best regards! |
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