UDF for Continuous Step Velocity Profile

nasehandarzgoo · November 8, 2013, 08:25

Hi.
I want to apply a continuous step velocity profile for my inlet.
I want it to keep fluctuating with period of 0.04 seconds until I stop iteration.
Would you please let me know how to do it and whether the way I have written that is correct.

Here is my UDF.

#include "udf.h"
DEFINE_PROFILE(Step_UDF,thread,position)
{
real x[ND_ND];
face_t f;
real u,u0=0.4;
real t;
begin_f_loop(f,thread)
{
F_CENTROID(x,f,thread);
t = RP_Get_Real("flow-time");
if ((fabs(t/0.04)%2)==0)
u=u0;
else
u=u0*1.03;
F_PROFILE(f,thread,position)=u;
}
end_f_loop(f,thread)
}

pakk · November 14, 2013, 09:11

Since you already have a proposed solution:
-did you try it?
-did it do what you wanted it to do?
-if not, what was wrong?

nasehandarzgoo · November 14, 2013, 12:15

Well I tried and found that I have to mention before that both sides of % are integer.
I just found it through trial and error.
I was actually hoping that someone give me a general solution.
What I did is working for me now.

Thank you

November 8, 2013, 08:25	UDF for Continuous Step Velocity Profile	#1
nasehandarzgoo New Member Naseh Hosseini Join Date: Jul 2012 Posts: 6 Rep Power: 14	Hi. I want to apply a continuous step velocity profile for my inlet. I want it to keep fluctuating with period of 0.04 seconds until I stop iteration. Would you please let me know how to do it and whether the way I have written that is correct. Here is my UDF. #include "udf.h" DEFINE_PROFILE(Step_UDF,thread,position) { real x[ND_ND]; face_t f; real u,u0=0.4; real t; begin_f_loop(f,thread) { F_CENTROID(x,f,thread); t = RP_Get_Real("flow-time"); if ((fabs(t/0.04)%2)==0) u=u0; else u=u0*1.03; F_PROFILE(f,thread,position)=u; } end_f_loop(f,thread) }

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November 14, 2013, 09:11		#2
pakk Senior Member Join Date: Nov 2013 Posts: 1,965 Rep Power: 27	Since you already have a proposed solution: -did you try it? -did it do what you wanted it to do? -if not, what was wrong?

November 14, 2013, 12:15		#3
nasehandarzgoo New Member Naseh Hosseini Join Date: Jul 2012 Posts: 6 Rep Power: 14	Well I tried and found that I have to mention before that both sides of % are integer. I just found it through trial and error. I was actually hoping that someone give me a general solution. What I did is working for me now. Thank you