[Yeyue]

Velocity changes with the temperature of the flow field. I don't know how the UDF calls the fluent temperature field. UDF programming is as follows, import fluent prompts the error as follows, I hope to get your help ~Thank you.

#include"udf.h"
DEFINE_PROFILE(in_x_velocity,cell,thread)
{
real x[ND_ND];
real y;
real temp=C_T(cell,thread);
real n;
real y;
face_t f;
begin_f_loop(f,thread)
{
F_CENTROID(x,f,thread);
y=x[1];
n=5.7171-0.009*temp;
y=4.7*10e-6*exp(6800/temp);
real yy;
yy=pow(m,1/n);
{ if(temp>291.15)
F_PROFILE(f,cell,thread)=0.02*(n+3)/(n+1)*(1-pow((y/0.010435),(n+1)));
else
F_PROFILE(f,cell,thread)=0.02*(n+3)/(n+1)*(1/(4*pow(1.52,n)+(n+3)*(5.964-0.02*temp)*100*1.52/yy)*(4*pow(1.52,n)/y*(1-pow((y/0.010435),(n+1)))+2(n+1)*(5.964-0.02*temp)*100*1.52/yy*(1-pow((y/0.010435),2))
}
end_f_loop(f,thread)
}


cpp -I"D:\ansys\ANSYS Inc\v150\fluent\fluent15.0.0/src" -I"D:\ansys\ANSYS Inc\v150\fluent\fluent15.0.0/cortex/src" -I"D:\ansys\ANSYS Inc\v150\fluent\fluent15.0.0/client/src" -I"D:\ansys\ANSYS Inc\v150\fluent\fluent15.0.0/multiport/src" -I. -DUDFCONFIG_H
"<C:/Users/ADMINI~1/AppData/Local/Temp/udfconfig-30856-node1.h>" "C:/Users/ADMINI~1/AppData/Local/Temp/Velocity1.c.30856.1.c"
Error: C:/Users/ADMINI~1/AppData/Local/Temp/Velocity1.c.30856.1.c: line 6: non-integer subscript expression: pointer to structure.

[AlexanderZ]

you must compile following

#include "udf.h"
#include "math.h"
DEFINE_PROFILE(in_x_velocity,t, i)
{
real x[ND_ND];
real y;
real temp;
real n;
real y;
real yy;
face_t f;
begin_f_loop(f,t)
{
	temp=F_T(f,t)
	F_CENTROID(x,f,t);
	y=x[1];
	n=5.7171-0.009*temp;
	y=4.7*10e-6*exp(6800/temp);
	yy=pow(m,1/n);
	{ if(temp>291.15)
	F_PROFILE(f,t,i)=0.02*(n+3)/(n+1)*(1-pow((y/0.010435),(n+1)));
	else
	F_PROFILE(f,t,i)=0.02*(n+3)/(n+1)*(1/(4*pow(1.52,n)+(n+3)*(5.964-0.02*temp)*100*1.52/yy)*(4*pow(1.52,n)/y*(1-pow((y/0.010435),(n+1)))+2(n+1)*(5.964-0.02*temp)*100*1.52/yy*(1-pow((y/0.010435),2))
	}
end_f_loop(f,t)
}

[Yeyue]

Hello, I modified it according to your comments, but the following problems will still occur, and I look forward to your reply.

#include"udf.h"
#include"math.h"
DEFINE_PROFILE(in_x_velocity,thread,index)
{
real x[ND_ND];
real y;
real n;
real yy;
real w;
real temp;
face_t f;
Thread *t;
begin_f_loop(f,thread)
{
temp=F_T(f,t);
F_CENTROID(x,f,thread);
y=x[1];
n=5.7171-0.009*temp;
yy=0.0000047*exp(6800/temp);
w=pow(yy,1/n);
{ if(temp>291.15)
F_PROFILE(f,thread,index)=0.02*(n+3)/(n+1)*(1-pow((y/0.010435),(n+1)));
else if(temp>=288.15&&temp>=291.15)
F_PROFILE(f,thread,index)=0.02*(n+3)/(n+1)*(1/(4*pow(1.52,n)+(n+3)*(5.964-0.02*temp)*100*1.52/w)*(4*pow(1.52,n)/yy*(1-pow((y/0.010435),(n+1)))+2(n+1)*(5.964-0.02*temp)*100*1.52/w*(1-pow((y/0.010435),2))
}
end_f_loop(f,thread)
}



cpp -I"D:\ansys\ANSYS Inc\v150\fluent\fluent15.0.0/src" -I"D:\ansys\ANSYS Inc\v150\fluent\fluent15.0.0/cortex/src" -I"D:\ansys\ANSYS Inc\v150\fluent\fluent15.0.0/client/src" -I"D:\ansys\ANSYS Inc\v150\fluent\fluent15.0.0/multiport/src" -I. -DUDFCONFIG_H
"<udfconfig.h>" "C:\Users\Administrator\Desktop\UDF\Velocity1. c"
Error: udfconfig.h: line 16: parse error.
-----------------------------------
best regards

[AlexanderZ]

https://www.youtube.com/watch?v=OPfgkORSESQ

[Yeyue]

I can't open the website you sent. Can you help me modify this program if you are convenient? Thank you very much.


--------------------------------------
best regards

[AlexanderZ]

make working directory
put there your case file and UDF file
open VIsual Studio console and run Fluent from this console
compile UDF, load UDF