UDF code not working
 

Hi,
I used the following code to increase the heat flux along a vertical wall from 0-500 linearly. However it doesn't work. I checked the wall heat flux at different locations in the CFD post, but it didn't give the right fluxes.Please let me know the correct solution.

DEFINE_PROFILE(lin_incr,t,i)
{
face_t f;
float x[ND_ND];
begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
F_PROFILE(f,t,i)=0+1250*x[0];
}
end_f_loop(f,t)
}

Which fluxes did it give, and which fluxes are the "right fluxes"?

It gave a uniform flux of 125 W/m2. It should increase from 0 to 500.

Does your boundary happen to be located at x=0.1 m?

What is probably happening: you wrote a UDF that varies linearly in x-coordinate, but your boundary varies in y-coordinate. (Or z-coordinate?)

Use x[1] in stead of x[0] if you want to vary in y-coordinate. (Or x[2] for z-coordinate.)

Yes! It works! Thanks a lot!