problem with Define_on_demand
 

dear all,

this is my code:

#include"udf.h"
#include"dpm.h"
#include"surf.h"
int num_injection = 4;


DEFINE_ON_DEMAND(initalize_udmis)
{
Domain *d=Get_Domain(1);
Thread *tc;
cell_t c;
int injno = 0;

/* Init UDM */
if(injno < num_injection)
{
thread_loop_c(tc,d){
begin_c_loop(c,tc)
{
C_UDMI(c,tc,injno)=0;
}
end_c_loop(c,tc)
}
injno++;
}
}

when i use this code for initializing the User defined memories (i already put the UDM limit to 10); i get segmentation violation.

why is this so ?
can you help me to avoid this problem.

sincerely.

Hi,

unfortunately I can not help you with your problem, but I'm experiencing exactly the same problem. I'm using DEFINE_ON_DEMAND and the UDM brings up a segmentation violation. I'm using FLUENT under Linux AMD 64, what are you using?

regards

Hi again,

I found the solution in this thread: http://www.cfd-online.com/Forums/flu...violation.html

I don't know why it works this way, but it works.... So You have to display the UDM in the contours before executing the UDF!

cheers

dear sir,

thank you for this very important message and for letting me know the work-around.

sincerely.

i still have problems with the UDF.
the initialization works.
however, the simulation crashes with:
Error: > (greater-than): invalid argument [2]: wrong type [not a number]
Error Object: nan

the UDF is related to the discrete model.
can anyone give some clue what is wrong ?

best wishes.

Hi there, I have the same problem now.... same error, did you find any solution?

cheers

dear sir,

i had since then modfied the code.
the nan however when something in denominator goes 0 or you have a negative exponent.
if you look into those areas, may be it can solve your problem.
i will look of i can help you with this any further if you can paste the code snippet.

good luck.