[tumbao]

Hi CFD mates,

I want to compute the temperature gradient in different solid zones of the domain. I found that the macro C_T_G can perform this task but I did not manage to get it working. Fluent always gives the same error: "Segmentation Violation"

Why ? How to solve this issue ?

I have looked here and there on the internet and I found many people who have the same problem, but I couldnt find any solution. Is it possible that there is a problem with the macro C_T_G itselft ?

Here is my code (which is basically the same as in the UDF guide of Fluent):


DEFINE_ON_DEMAND(Temp_grad_ondemand)
{
Domain *d;
cell_t c;
Thread *t;
d = Get_Domain(1);

thread_loop_c(t,d)
{
begin_c_loop(c,t)
{

C_UDMI(c,t,1) = NV_MAG(C_T_G(c,t));

}
end_c_loop(c,t)
}

}

Thanks mates !

[johnwinter]

Hi tumbao,

Did you add header file mem.h in your udf?? and also did you run the text command solve/set/expert??

This will Keep temporary solver memory from being freed?.
Note that when you do this, all of the gradient data is retained, but the calculation requires more memory to run

[Apiano]

You need to allow the derivatives in order to store gradients.