UDF boundary
 

#include "udf.h"
#include<math.h>

DEFINE_PROFILE(inlet_z_velocity_A, t, i)
{
real x[ND_ND];
real a;
real y;
face_t f;
begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
a=x[0];
y=x[1];

if ((-4.2 <= a) && (a < -3.945))
F_PROFILE(f, t, i) = -0.088*pow(y, 5) - 0.0737*pow(y, 4) + 0.1308*pow(y, 3) + 0.0682*pow(y, 2) - 0.0665*y + 0.3545;

if ((-3.945 <= a) && (a < -3.675))
F_PROFILE(f, t, i) = 0.1012*pow(y, 6) + 0.0131*pow(y, 5) - 0.2807*pow(y, 4) - 0.0547*pow(y, 3) + 0.1929*pow(y, 2) + 0.0411*y + 0.3549;

if ((-3.675 <= a) && (a < -3.405))
F_PROFILE(f, t, i) = 0.046*pow(y, 6) + 0.0045*pow(y, 5) - 0.1283*pow(y, 4) + 0.0002*pow(y, 3) + 0.1014*pow(y, 2) - 0.0034*y + 0.3668;

if ((-3.405 <= a) && (a < -3.135))
F_PROFILE(f, t, i) = 0.0752*pow(y, 6) + 0.0194*pow(y, 5) - 0.2078*pow(y, 4) - 0.0361*pow(y, 3) + 0.1624*pow(y, 2) + 0.0196*y + 0.3454;

if ((-3.135 <= a) && (a < -2.865))
F_PROFILE(f, t, i) = -0.6608*pow(y, 6) - 0.0257*pow(y, 5) + 1.4898*pow(y, 4) + 0.0128*pow(y, 3) - 0.9274*pow(y, 2) + 0.012*y + 0.5025;

if ((-2.865 <= a) && (a < -2.595))
F_PROFILE(f, t, i) = 0.164*pow(y, 6) + 0.0698*pow(y, 5) - 0.3511*pow(y, 4) - 0.087*pow(y, 3) + 0.2244*pow(y, 2) + 0.0301*y + 0.3417;

if ((-2.595 <= a) && (a < -2.325))
F_PROFILE(f, t, i) = -0.0257*pow(y, 5) - 0.0798*pow(y, 4) + 0.022*pow(y, 3) + 0.0863*pow(y, 2) - 0.008*y + 0.3762;

if ((-2.325 <= a) && (a < -2.055))
F_PROFILE(f, t, i) = 0.05*pow(y, 6) - 0.0019*pow(y, 5) - 0.1895*pow(y, 4) + 0.0122*pow(y, 3) + 0.1427*pow(y, 2) - 0.0089*y + 0.3693;

if ((-2.055 <= a) && (a <= -1.8))
F_PROFILE(f, t, i) = 0.1494*pow(y, 6) - 0.0899*pow(y, 5) - 0.3818*pow(y, 4) + 0.2512*pow(y, 3) + 0.2011*pow(y, 2) - 0.1668*y + 0.4045;
}
end_f_loop(f,t)
}

Hello！
Please help me!
Thanks!

I wrote a UDF to describe the velocity of a air supply diffusion belonging to “velocity-inlet “. And the UDF could be compiled successfully. However, when the iteration reached 500 steps, continuity residual curve kept raising. Then the TUI noted that computational diergence.

The above is my UDF.
Thanks!

May you try this format for if else ladder in your UDF?
if (testExpression1)
{
// statement(s)
}
else if(testExpression2)
{
// statement(s)
}
else if (testExpression 3)
{
// statement(s)
}
.
.
else
{
// statement(s)
}

Thanks for your reply！
I will try it！thanks！