UDF 2D inlet profile

Thomashoffmann · January 16, 2013, 06:40

Hi all.

I'm up to write a UDF inlet profile. The inlet profile should be given by:
v=0.001474*(1-(r/R)^3).

By studying other examples I've come to the code shown here below. But I get an error in line 11 'no function prototype', when I try to interpret it. Can anybody help?
Thanks

__________________
#include "udf.h"
DEFINE_PROFILE(inlet_velocity_x, t, i)
{
real x[ND_ND]; /* this will hold the position vector*/
real y;
face_t f;
begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
y=x[1]
F_PROFILE(f,t,i) = 0.001474*(1-((0.024-y)/0.024)^3)
}
end_f_loop(f,t)
}

Thomashoffmann · January 16, 2013, 08:40

Ok, I figured it out... I forgot the semicolons in line 10 and 11, and for some reason it is not allowed to use '^3', so I just wrote: ((0.024-y)/0.024)*((0.024-y)/0.024)*((0.024-y)/0.024)...

coglione · January 17, 2013, 02:47

a more elegant way for x^y: pow(x,y)

cheers

Thomashoffmann · January 17, 2013, 03:38

I have never worked with C code before, but thanks for the input

January 16, 2013, 06:40	UDF 2D inlet profile	#1
Thomashoffmann Member Thomas Hoffmann Join Date: Oct 2012 Posts: 67 Rep Power: 13	Hi all. I'm up to write a UDF inlet profile. The inlet profile should be given by: v=0.001474(1-(r/R)^3). By studying other examples I've come to the code shown here below. But I get an error in line 11 'no function prototype', when I try to interpret it. Can anybody help? Thanks __________________ #include "udf.h" DEFINE_PROFILE(inlet_velocity_x, t, i) { real x[ND_ND]; / this will hold the position vector/ real y; face_t f; begin_f_loop(f,t) { F_CENTROID(x,f,t); y=x[1] F_PROFILE(f,t,i) = 0.001474(1-((0.024-y)/0.024)^3) } end_f_loop(f,t) }

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January 16, 2013, 08:40		#2
Thomashoffmann Member Thomas Hoffmann Join Date: Oct 2012 Posts: 67 Rep Power: 13	Ok, I figured it out... I forgot the semicolons in line 10 and 11, and for some reason it is not allowed to use '^3', so I just wrote: ((0.024-y)/0.024)((0.024-y)/0.024)((0.024-y)/0.024)...

January 17, 2013, 02:47		#3
coglione Senior Member Max Join Date: Mar 2009 Posts: 133 Rep Power: 17	a more elegant way for x^y: pow(x,y) cheers

January 17, 2013, 03:38		#4
Thomashoffmann Member Thomas Hoffmann Join Date: Oct 2012 Posts: 67 Rep Power: 13	I have never worked with C code before, but thanks for the input