[PXY]

Hello everyone,
I'm writing a code to define the wall shear stress, but it's always wrong. How to write it correctly?

τzx=-(σz*f+(ρ*g*vx^2)/ξ)

#include"udf.h"
#define F 0.3 /*friction coefficient*/
#define B 1000 /*turbulence parameter*/
#define D 1630 /*density*/
#define g 9.81
DEFINE_PROFILE(taux_profile, t, i)
{
real u, p;
face_t f;
Thread* t0;
cell_t c0;
begin_f_loop(f, t)
{
t0 = THREAD_T0(t);
c0 = F_C0(f, t);
p = C_P(c0, t0);
u = C_U(c0, t0);
F_PROFILE(f, t, i) = p * F + D * g * u * u / B;
}
end_f_loop(f, t)
}
DEFINE_PROFILE(tauy_profile, t, i)
{
real v, p;
face_t f;
Thread* t0;
cell_t c0;
begin_f_loop(f, t)
{
t0 = THREAD_T0(t);
c0 = F_C0(f, t);
p = C_P(c0, t0);
v = C_V(c0, t0);
F_PROFILE(f, t, i) = p * F + D * g * v * v / B;
}
end_f_loop(f, t)
}