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Ansys Fluent UDF, Wall Average Temperature Depend On Inlet Velocity

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Old   April 13, 2019, 10:35
Default Ansys Fluent UDF, Wall Average Temperature Depend On Inlet Velocity
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ozge akbulbul
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Hello All,


I am trying to write "UDF fluent code" that wall average temperature condition depend on inlet velocity. I have the face which ID is 9 and its average temperature depend on inlet velocity. When face average temperature increases, inlet velocity increases each time step (transient).

-I use fluent on serial
-I use it on transient, energy on, viscous- k-eps or laminar
-I have increased Number of user defined memory location
-I have interperated my code as (kod.c) (which is has no error on command)
-I have done that add function hooks on Execute at end as (execute_at_end)
-I have added inlet velocity magnitude as (unsteady_velocity)


When I run calculation, after one time step (for instance 10 or 20 iteration) I got error which is; which mean is I can't go through second time step.


Error: received a fatal signal (Segmentation fault). Error Object: #f


The code is;

%%%%%%%%%%%%%%%%%%%%%%%%%

#include "udf.h"
real T_mean;

DEFINE_EXECUTE_AT_END(execute_at_end)
{
Domain *domain;
Thread *thread;
face_t face;
real area[ND_ND];
real total_area = 0.0;
real total_area_ave_temp = 0.0;
int ID = 9;
domain = Get_Domain(1);
thread = Lookup_Thread(domain, ID);
begin_f_loop(face, thread)
F_AREA(area, face, thread);
total_area += NV_MAG(area);
total_area_ave_temp += NV_MAG(area)*F_T(face, thread);
end_f_loop(face, thread)
T_mean = total_area_ave_temp/total_area;
printf("Area averaged T on boundary %d = %f K\n", ID, T_mean);
}


DEFINE_PROFILE(unsteady_velocity, thread, position)
{
face_t f;
real t = CURRENT_TIME;
begin_f_loop(f, thread)
{
F_PROFILE(f, thread, position) = (T_mean-273) ;
}
end_f_loop(f, thread)
}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


I would be grateful if I solve this problem with your helps, thank you very much

Best regards.
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Old   April 15, 2019, 01:31
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Alexander
Join Date: Apr 2013
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AlexanderZ will become famous soon enoughAlexanderZ will become famous soon enough
you've missed brackets here:
Code:
begin_f_loop(face, thread)
{
F_AREA(area, face, thread);
total_area += NV_MAG(area);
total_area_ave_temp += NV_MAG(area)*F_T(face, thread);
}
end_f_loop(face, thread)
how it is possible to have this error and no error after compilation?
change printf to Message

you have Error: received a fatal signal (Segmentation fault). Error Object: #f error, because your T_mean was not calculated, so you are trying to put -273 as a boundary condition, or any other trash
by the way, check your units for temperature, by default fluent uses Kelvin

best regards
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