[srv537]

i am using fluent and i have used UDF for parabolic velocity profile for 2D case at inlet as

#include "udf.h"
DEFINE_PROFILE(inlet_x_velocity, thread, position)
{
real x[ND_ND]; /* this will hold the position vector */
real y;
face_t f;
begin_f_loop(f, thread)
{
F_CENTROID(x,f,thread);
y = x[1];
F_PROFILE(f, thread, position) = 0.4382 - y*y/(0.005*0.005)*0.4382;
}
end_f_loop(f, thread)
}


now i want to use UDF for 3D case, how can i convert this for 3D case?
please help me

thanks in advance

[FMDenaro]

the 3D problem you wanto to study has 4 walls? In such case you must solve the elliptic equation Lap w = q on the inflow plane (w is the streamwise velocity, q depends on the pressure gradient and Re number)

[srv537]

Originally Posted by FMDenaro

the 3D problem you wanto to study has 4 walls? In such case you must solve the elliptic equation Lap w = q on the inflow plane (w is the streamwise velocity, q depends on the pressure gradient and Re number)

yes four wall but i just want to specify (u) normal component of velocity at inlet surface and v=w=0.

[FMDenaro]

Originally Posted by srv537

yes four wall but i just want to specify (u) normal component of velocity at inlet surface and v=w=0.

I called w the streamwise component that you called u. It is the same, you must solve the 2D Poisson problem.

[srv537]

Originally Posted by FMDenaro

I called w the streamwise component that you called u. It is the same, you must solve the 2D Poisson problem.

actually i want to modify this code for 3D velocity profile and compile to fluent as a inlet boundary condition.
i dont know how to do this