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-   -   UDF for a horizontal temperature profile (http://www.cfd-online.com/Forums/fluent-udf/43764-udf-horizontal-temperature-profile.html)

CD February 15, 2007 06:15

UDF for a horizontal temperature profile
 
Hello,

I'm trying to write an UDF for a temperature profile to use as an boundary condition on a horizontal wall (2D). I used the following UDF, but when I plot an xy-plot of the wall surface temperature it is just a constant. Can anybody tell me what I'm doing wrong?

Kind regards,

CD

/* test.c UDF for specifying temperature profile boundary condition on the bottom */

#include "udf.h"

DEFINE_PROFILE(test,thread,position)

{ real x[ND_ND]; /* this will hold the position vector */

real y;

face_t f;

begin_f_loop(f,thread)

{

F_CENTROID(x,f,thread);

y=x[1];

F_PROFILE(f, thread, position) = ... */ here stands the profile function as a function of y /*

}

end_f_loop(f,thread)

}


Rizwan February 15, 2007 16:36

Re: UDF for a horizontal temperature profile
 
this should be proper. dint chek it (as simulation running on my system) but thsi my understnading that temperature is varying along horizontal (along x) i guess .

#include "udf.h"

DEFINE_PROFILE(test,thread,position)

{ real x[ND_ND]; /* this will hold the position vector */

real y;

face_t f;

begin_f_loop(f,thread)

{

F_CENTROID(x,f,thread);

y=x[0];

F_PROFILE(f, thread, position) = ... */ here stands the profile function as a function of y /*

}

end_f_loop(f,thread)

}


Ted February 16, 2007 05:10

Re: UDF for a horizontal temperature profile
 
Thank you for your time and help Rizwan!

Ted


Rizwan February 16, 2007 07:30

Re: UDF for a horizontal temperature profile
 
I wish you could hav told whether its working according to what u needed or not. Regards waiting for ur input.

Ted February 17, 2007 15:02

Re: UDF for a horizontal temperature profile
 
I was using the y-coordinate of a horizontal walll instead of the x-coordinate, so logically the result of my profile function was a constant. With your correction the UDF is now working just as I hoped. Thanks again!

Greetings Ted


str6073 July 20, 2013 10:51

hi guys

i need a udf for a work. i'll explain what i need . I want to provide a linear varying temperature boundary condition on the circular side of a cylinder . can you help me?? My idea about udf is very small.

ettehadi December 15, 2013 16:07

tempereture udf for wall BC
 
I am trying to write UDF for wall of vertical pipe temperature that increase with increasing depth (Z). UDF is as follow

#include "udf.h"
DEFINE_PROFILE (gradient_temp,thread,nv)
{
face_t f;
real x[ND_ND];
/*loop over each of the face of this zone*/
begin_f_loop (f,thread)
{
F_CENTROID(x,f,thread);
F_PROFILE(F,THREAD,NV)=25.*z[0]+80
}
end_f_loop (f,thread)
}

but fluent gets some error as below:

..\..\src\tempgrad.c(10) : error C2065: 'THREAD' : undeclared identifier
..\..\src\tempgrad.c(10) : error C2223: left of '->storage' must point to struct/union
..\..\src\tempgrad.c(10) : error C2065: 'NV' : undeclared identifier
..\..\src\tempgrad.c(10) : error C2065: 'F' : undeclared identifier
..\..\src\tempgrad.c(10) : error C2065: 'z' : undeclared identifier
..\..\src\tempgrad.c(10) : error C2109: subscript requires array or pointer type
..\..\src\tempgrad.c(11) : error C2143: syntax error : missing ';' before '}'



could any one can help me what is the problem?????

Zaktatir December 15, 2013 17:07

theYour problem not defined z and the wrong THREAD instead of thread C is uppercase sensitive


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