Udf for a fully developed velocity profile atinlet
 

I need to specify a boundary condition at the inlet region of a square duct. At the inlet i want to specify a fully developed velocity profile. I know i need to use a UDF. The fluent manual gives examples of a fully developed velocity profile at the inlet for a 2d example but not 3d. Has anybody ever done this. would you be willing to send me your c code if you have?

Re: Udf for a fully developed velocity profile ati
 

Hi, meppen, I have met a question, it seems that you could help me.I don't know where can I find an example of a fully developed velocity profile at the inlet for a 2d example using UDF.Thanks in advance. sincerely, houston

Re: Udf for a fully developed velocity profile ati
 

Philip,

click the following link:

http://www.cfd-online.com/Search/cgi...cfd-online.com%2FForum%2Ffluent;exclude=;config=htdig;method=and ;sort=score;words=velocity%20profile;page=1

and then read the post titled as:

Re: problem in 3d parabolic velocity profile****

You will get some ideas about the C code for 3D.

By the way, could you send me the c code for 2D fully developed velocity profile?

Re: Udf for a fully developed velocity profile ati
 

Hi, I need the UDF for 2D. would you pleas give me?

Example of a parabolic velocity profile in 2D:
************************************
#include "udf.h"
DEFINE_PROFILE(x_velocity,thread,index)
{
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,index) = 20. - y*y/(.0745*.0745)*20.;
}
end_f_loop(f,thread)
}
*********************************************
Ref. : FLUENT UDF manual.

thernall fully developed
 

thank you, but is it suitable to reach thermal fully developed?if not what is your suggestion?

I'm not exactly sure about the thermal boundary layer, but since the parabolic profile is suitable for the laminar flow boundary layer (for Re lower than 1000), I suppose it is correct to use it in a numerical procedure.