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Rich1979 March 18, 2011 03:31

Power load UDF
 
Hi everybody,
I have a question : i have to write an UDF for a thermal load on a surface (lateral surface of a truncated cone).The thermal load follows the law P(z) = a*z^b where z is the distance from the source.
How could i set up my UDF?
Thx mates.

Amir March 18, 2011 04:05

Hi,
you can do that with DEFINE_PROFILE macro and hook that in heat flux boundary condition.

Rich1979 March 18, 2011 05:49

Thx for your answer :)
Could it be something like :

Quote:

#include "udf.h"

DEFINE a 1
DEFINE b 2
DEFINE_PROFILE (powerload, t, i)
{
real x[ND_ND];
real y;
real z;
face_t f;

begin_f_loop(f, t)
{
F_CENTROID(x,f,t);
z = x[1];
F_PROFILE(f, t, i) = a*z^b;
}
end_f_loop(f, t)
}
At ND_ND have i to put 3D_3D?
Thx again for your support!

Amir March 18, 2011 08:34

it needs some changes:
Code:

#include "udf.h"
#include "math.h"
#define a 1
#define b 2
DEFINE_PROFILE (powerload, t, i)
{
  real x[ND_ND];               
  real z;   
  face_t f;
  begin_f_loop(f, t)
    {
      F_CENTROID(x,f,t);
      z = x[2];
      F_PROFILE(f, t, i) = a*pow(z,b);
    }
  end_f_loop(f, t)
}

it doesn't need to change ND_ND. it automatically adopts itself.

Rich1979 March 21, 2011 02:05

Thx a lot Amir,your advise was very useful!I realized my udf :)


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