[darchz]

I'm new in FLUENT, now working on my architecture project to simulation wind through
high-rise building. I need to use log-law wind profile in 3D domain as attached picture.

I read from post and working on UDF as many suggestion. I curious why it doesn't work
for my case. All I've got is error massage "floating point exception".

Here is my udf file:

#include "udf.h"

DEFINE_PROFILE(log_law_velocity,thread,position)
{
real x[ND_ND];
real y;
face_t f;
begin_f_loop(f,thread)
{
F_CENTROID(x,f,thread);
y = x[1];
F_PROFILE(f,thread,position) = 10*log(y/0.6)/log(10/0.6);
}
end_f_loop(f,thread)
}

Or if you have other way to create this condition please let me know.

I Would greatly appreciate any help,
Best Regards
Jirawat.