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-   -   FLUENT received fatal signal (ACCESS_VIOLATION) (http://www.cfd-online.com/Forums/fluent/67175-fluent-received-fatal-signal-access_violation.html)

CHAKER August 6, 2009 08:41

FLUENT received fatal signal (ACCESS_VIOLATION)
 
Hi everyone,
i have to simulate a stirred tank with turbulent multiphase flow,
the problem is when i stoped the similuation and i want to restart it, a message of error appears
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: ()

please any idea???

krisp August 6, 2009 10:10

It might be due to:
  1. You might have changed the folder name after the case ran. so if you have data files to be written out change their path,
  2. Perform solve->Initialize flow
  3. If you have UDF's recompile them,
  4. You may want to reset the case and see if it persists,
  5. Things differ a bit if you use UNIX.

kuldeepnitb@gmail.com December 10, 2015 07:10

Udf run problem
 
Hello I am Kuldeep Kumar. I am new with Ansys flunet. I am writing a udf for the heat exchage process. I am going step by step. Here i am writing a simple udf code for temperature and pressure source calculation, but this is showing error as given below :
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: #f

My simple udf code is given as:
DEFINE_EXECUTE_AT_END(source_calculation)
{
Domain *d;
Thread *t;
cell_t c;
real time = CURRENT_TIME;
real temp, Pg, abrate, Peqa, Peqd, mab, mde, m,volume;
real xc[ND_ND];
int zone=2;
d = Get_Domain(1);
t=Lookup_Thread(d,zone);
begin_c_loop(c,t)
{
temp=C_T(c,t);
Pg= C_P(c,t);
Peqa=1000*exp(Aab-Bab/temp);
mab=-Ca*exp(-Ea/(Rg*temp))*log(Pg/Peqa)*(Psat-Pemp);
}
end_c_loop(c,t);
}

Can anybody me about this problem ?

LuckyTran December 10, 2015 11:17

This type of error is encountered when Fluent tries to do something and then finds out that it didn't do it. Unfortunately the error is empty "Error Object: #f" so we have no clue what it is. It could have been anything.

Is the error persistent and is it always encountered at the same point? If it was a one time error then I'd say move along because this error can randomly occur from time to time. Usually it's the OS's fault with the job scheduler. Running more than one task can cause Fluent to hang.

pakk December 11, 2015 04:20

Your udf tries to get temperatures and pressures from cells in zone 2. This could fail in many ways:
1. Zone 2 does not exist.
2. Zone 2 exists, but has no cells but faces (it is for example a wall).
2. Zone 2 exists and has cells, but no temperatures (you are simulating without energy equation).

Furthermore, does your code know what Aab, Bab, Ca, Ea, Rg, Psat and Pemp are? I don't see them anywhere defined in your code (maybe you omitted that part...)

By the way: your udf does not give any output the way you programmed it now.


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