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-   -   UDF for transient conduction. (http://www.cfd-online.com/Forums/fluent-udf/119740-udf-transient-conduction.html)

Ravindra123 June 24, 2013 05:14

UDF for transient conduction.
 
Hi,
I am solving a transient conduction problem when a side of the plate is subjected to time and space varying boundary condition. I am using a udf which is as follows:

/************************************************** ******************** UDF for specifying a transient velocity profile boundary condition ************************************************** ********************/


#include "udf.h"


DEFINE_PROFILE(temp, t, i)


{

real x[ND_ND];


real x0, y0, time;


face_t f;


time = CURRENT_TIME;


begin_f_loop(f, t)


{


F_CENTROID(x,f,t);


x0 = x[0];


y0 = x[1];


F_PROFILE(f, t, i) = 100.0*sin(y0)*sin(3.14*time)+200.0*cos(y0)*cos(3.1 4*time);


}


end_f_loop(f, t)

}


Now the problem is after solving the problem in fluent, when i monitor the temperature at a point on the surface of the wall, I am not getting the temperature variation as given to the UDF. Does this problem is related to time step i am using? or there is the problem in the UDF? Any help would be appreciated...
Thanks..

avi@lpsc August 23, 2013 14:31

Temp.varying with space and Time
 
Hi Ravindra

Whether you have sorted out the problem with your transient conduction udf? I am looking for a very similar udf for temperature varying with space and time..Could you please forward me the model udf for same.

harsh_999 October 20, 2013 09:45

Quote:

Originally Posted by Ravindra123 (Post 435560)
Hi,
I am solving a transient conduction problem when a side of the plate is subjected to time and space varying boundary condition. I am using a udf which is as follows:

/************************************************** ******************** UDF for specifying a transient velocity profile boundary condition ************************************************** ********************/


#include "udf.h"


DEFINE_PROFILE(temp, t, i)


{

real x[ND_ND];


real x0, y0, time;


face_t f;


time = CURRENT_TIME;


begin_f_loop(f, t)


{


F_CENTROID(x,f,t);


x0 = x[0];


y0 = x[1];


F_PROFILE(f, t, i) = 100.0*sin(y0)*sin(3.14*time)+200.0*cos(y0)*cos(3.1 4*time);


}


end_f_loop(f, t)

}


Now the problem is after solving the problem in fluent, when i monitor the temperature at a point on the surface of the wall, I am not getting the temperature variation as given to the UDF. Does this problem is related to time step i am using? or there is the problem in the UDF? Any help would be appreciated...
Thanks..

Hi Ravindra,
Have u written ur profile right?
i dont c it is a function of x though u've defined x0
u've written it as a function of y only
inform d check
good luck


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