[Siddharth17]

So i wrote the following snippet in order to obtain a power law velocity profile for my inlet BC.The z is the z co-ordinate and while i was able to interpret and hook the udf. as soon as start calculating the velocity, the continuity and all 3 velocities remain zero in residuals and only k & w are iterating.
My main aim is to do for transient k-w sst simulations but I also switched to steady just to check but it didnt work. Pls enlighten me as I am new to this UDF.
Another i would want to know is how to plot velocity vs z-coordinate while calculating solution
pls see the attachments


#include "udf.h"

DEFINE_PROFILE(x_velocity,thread,index)
{
real coord[ND_ND]; /* this will hold the position vector */
real z;
face_t f;

begin_f_loop(f,thread) /* loops over all faces in the thread passed
in the DEFINE macro argument */
{
F_CENTROID(coord,f,thread);
coord[2]=z;
F_PROFILE(f,thread,index)= 80.6715 * pow(z/323, 0.3584);
}
end_f_loop(f,thread)
}

[AlexanderZ]

tobe

z=coord[2];

was

coord[2]=z;

[somanna]

F_PROFILE(f,thread,index)= 80.6715 * pow(z/323, 0.3584)


From where did you get this? is there a standard expression? and what does the values stand for??