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UDF - define_init & restart problem

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Old   December 3, 2012, 17:27
Question UDF - define_init & restart problem
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JŠn
Join Date: Mar 2010
Location: Slovakia
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Dear friends,
There is one thing I cant figure out. I interpreted my UDF which was made as follows:
Define_init function. Is to examine the geometry parameters, to simplify it, it returns the total volume (c_tot variable) of the cells.
Define_source (whatever define macro), uses this value, such as x/c_tot. Everything works fine, until I end the calculation, write a .dat file and restart the calculation without initialization. Seems to be (and Im pretty sure), that Fluent does not store the c_tot value, in general any value, obtained from define_init once the calculation is over and then restarted. I really dont want to use a define_adjust (it will uselessly slow down my calculation), or define_on_demand (want to keep it to be performed automatically). Is there any way to store that value for the next usage?
Thank you in advance.
j.
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Old   December 4, 2012, 12:19
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JŠn
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Hi again,
so it seems to be that I moved on a bit.
I found out that use of C_UDMI could be suitable for this kind of problem, anyway there is still an issue I cant pass through.
To explain it more closely:

Code:
DEFINE_INIT (init, domain)
{
  real ...
  thread_loop_c(t, domain);
      {
      begin_c_loop(c, tc)
        if (sth)
        {
        C_UDMI(c, tc, 0)+=C_VOLUME(c, tc);
        }
      end_c_loop(c, tc)
      }
}

and then

DEFINE_SOURCE(energy, c, thread, dS, eqn)
{
   real ...
   var1=var2/C_UDMI(c, tc, 0)
   source=var3; 
   dS[eqn]=var4;
   return source;
}
Please have a look on that. Problem is, that C_UDMI is returning zero value (as an output from ini function), and I dont have a clue why.
Maybe I just dont understand how C_UDMI is working.
The second question is - Will be the C_UDMI value stored after I re-interpret my UDF, or restart the calculation from a .dat file? (Will be this value written into a .dat file?).
For now, Im using on demand macro, but it is not so pretty as I would like to..
Thank you in advance.
Regards

Last edited by argeus; December 4, 2012 at 14:03.
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