[n7310889]

Hi, could any of you can tell me whats wrong with this macro? Its for 3d to provide input heat-flux profile around a semi circular cylinder of 33mm radius and 1.5m long.The heat profile varies along the verticle y direction and translates the same along the horizontal z axis.

#include "udf.h"

DEFINE_PROFILE(heat_profile,thread,index)
{
real x[ND_ND];
real x,y,z,r,angle;

face_t f;

begin_f_loop(f,thread)
{
F_CENTROID(x,f,thread);

x =x[0];
y =x[1];
z =x[2];
r =sqrt(pow(x,2)+pow(y,2));
angle =acos(-y/r);

if ((z>=0.0) && (z<=1.4))
{

if ((angle>=0.0) && (angle<=60.0))
{
F_PROFILE(f,thread,index) =6500.0;
}

if ((angle>50.0) && (angle<=180.0))
{
F_PROFILE(f,thread,index) =0.0;
}

}

else
{
F_PROFILE(f,thread,index) =0.0;
}
}

end_f_loop(f,thread)
}

[KAA]

Can u please tell the meaning of 6500 in your program.

[AlexanderZ]

Originally Posted by KAA

Can u please tell the meaning of 6500 in your program.

6500 is a value, which will be applied as a boundary condition

best regards

[farhanjaved]

@AlexanderZ, is your UDF looping over all the faces? try printing the value of the face centroid and seeing if the UDF is going over all the faces.
I am also trying to create a radially varying heat flux for a circular surface. But my UDF surprisingly does not loop over all the faces. This is my udf.

We could both help each other out.

# include "udf.h"
DEFINE_PROFILE(heatfluxshoulder,thread,position)
{ face_t f;
cell_t c;
float x[ND_ND];
float xx,z,r,omega,w,sigma, uf,qs1,ql1,hflux,taustick, tauslide, rshoulder, rpin, pressure, yield, qtotal;
begin_f_loop(f,thread)
{
pressure=17700;
yield=35000000;
omega=800;
rshoulder=0.014;
rpin=0.003;
w=2*3.14*omega/60;
F_CENTROID(x,f,thread);
xx=x[0];
z=x[2];
r=sqrt((xx*xx+z*z));
sigma=0.31*exp(w*r/1.87)-0.026;
uf=0.5*exp(-sigma*w*r);
taustick=yield/1.73;
tauslide=uf*pressure;
qs1=0.67*3.14*w*taustick*(rshoulder*rshoulder*rsho ulder-
rpin*rpin*rpin);
ql1=0.67*3.14*w*tauslide*(rshoulder*rshoulder*rsho ulder-
rpin*rpin*rpin);
qtotal=sigma*(qs1)+(1-sigma)*(ql1);
hflux=(qtotal/4847)*1.7e+010;
F_PROFILE(f,thread,position) = hflux;
}
end_f_loop(f,thread)
}