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How can I implement temperature jump boundary condition in microchannel walls?

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Old   September 7, 2010, 06:07
Default How can I implement temperature jump boundary condition in microchannel walls?
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sima
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Hi,

I want to apply slip velocity and temperature jump boundary condition to the walls of a two-dimensional channel in Fluent.
I use your report (IFTR reports). There is not any problem for slip boundary condition but the following errors appear when I apply temperature jump to the wall:


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: ()





I'd be grateful if someone help me.
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Old   April 2, 2011, 00:08
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P Kaushik
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This is a common problem faced if the C_T_G or the temperature gradient is used in the temperature jump udf. Initially there no temperature gradient in general problems, hence accessing C_T_G becomes a problem and gives this error.
The solution is simple. All you need to do is run a few iterations, say 3 or 5 without this udf and then add the udf to your boundary condition and continue.

Good luck!
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Old   April 2, 2011, 05:56
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Hi,
you should prevent FLUENT from freeing up gradients data before.
in TUI : solve/set/expert and then answering yes to the question Keep temporary solver memory from being freed?
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Old   September 1, 2011, 18:10
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hadi ramin
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hi amir
i have the same problem during the using of slip boundary condition, I checked your comment and again I have the same error
is anything I must apply?
thanks in advanec
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Old   September 2, 2011, 02:46
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Quote:
Originally Posted by hadiramin View Post
hi amir
i have the same problem during the using of slip boundary condition, I checked your comment and again I have the same error
is anything I must apply?
thanks in advanec
Hi Hadi,
If your UDF contains gradient commands, probable problem which you may encounter is that these parameters do not have any value at first iteration; so, my suggestion before implementing of your UDF is that to store some values in these parameters. you can do that by few pre-iterations or patching parameters (in the cases you've used UDMs).

Bests,
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Old   September 2, 2011, 03:34
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hadi ramin
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thanks amir jan for your request
I do every thing, but it has the error.
can I send to you my UDF and you checked it?
It's related to my projects and I need it immediately.
can I have your email?
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