I used following UDF for fully developed 3d profile in a pipe. The problem is that it doesn,t results in a smooth profile. When I check velocity magnitude contour at the inlet the profile is distorted (However it gives smooth paraboloid plot for x-velocity).

DEFINE_PROFILE(inlet_x_velocity, thread, position) { real x[ND_ND]; real r; face_t f;

begin_f_loop(f, thread)

{

F_CENTROID(x,f,thread);

r = sqrt(pow(x[1],2)+pow(x[2],2));

F_PROFILE(f, thread, position) = 0.019865*(1-pow (r/0.0254,2));

} end_f_loop(f, thread) }

You should check the profile at the cross section a little post of the inlet to see if the profile is still distorted or just same as what you defined.