[Nabat]

I want to simulate a plasma on two sides of the cylinder in -90 and 90 degree locations with duty cycle 50%. I wrote it with IF and Loop but it is not working. I would be thankful if you could guide me where is my mistake. I would be thankful if you could guide me.

[AlexanderZ]

Originally Posted by Nabat

I want to simulate a plasma on two sides of the cylinder in -90 and 90 degree locations with duty cycle 50%. I wrote it with IF and Loop but it is not working. I would be thankful if you could guide me where is my mistake. I would be thankful if you could guide me.

something wrong with your UDF

best regards

[Nabat]

Originally Posted by AlexanderZ

something wrong with your UDF

best regards

Yes, but I could not find what is it. Could you guide me. Here it is.

Regards

#include "udf.h"
#define con 1000
DEFINE_SOURCE(plasmasource,cell,thread,ds,eqn)
{
real x[ND_ND];
real t;
real source;
cell_t c;
real y;
t=CURRENT_TIME;
/*Now making source not dependant on velocities where con[N/m^2]*/

begin_f_loop(c,t)
{
C_CENTROID(x,cell,thread);
y=sin(t);
if (y>0.)
{
if(x[0]>-.001 && x[0]<.001 && x[1]>.0127 && x[1]<.0128)
{
source=con;
ds[eqn]=0;
}
else
{ source=ds[eqn]=0;}
}
else
{ source=ds[eqn]=0;}
return source;
}
end_f_loop(c,t)
}

begin_f_loop(c,t)
{
C_CENTROID(x,cell,thread);
y=sin(t);
if (y>0.)
{
if(x[0]>-.001 && x[0]<.001 && x[1]>.0127 && x[1]<.0128)
{
source=con;
ds[eqn]=0;
}
else
{ source=ds[eqn]=0;}
}
else
{ source=ds[eqn]=0;}
return source;
}
end_f_loop(c,t)
}

[AlexanderZ]

I can only guess, what exactly you want. May be this code is OK for your case

#include "udf.h" 
#define con 1000 
DEFINE_SOURCE(plasmasource,cell,thread,ds,eqn) 
{ 
real x[ND_ND]; 
real t; 
real source; 
real y;
t=CURRENT_TIME; 
/*Now making source not dependant on velocities where con[N/m^2]*/ 

C_CENTROID(x,cell,thread);
y=sin(t);
if (y>0.)
{
if(x[0]>-.001 && x[0]<.001 && x[1]>.0127 && x[1]<.0128) 
{ 
source=con; 
ds[eqn]=0; 
} 
else 
{source=0; ds[eqn]=0;} 
} 
else
{source=0; ds[eqn]=0;} 

return source;
}

best regards

[Nabat]

Thank you for your guidance. Could you tell me why we do not need loop for different time steps. I also attached my geometry in which the locations of 2 plasmas are shown. Should I add one more if, to add the second plasma? Thank you very much for you time.

[AlexanderZ]

Originally Posted by Nabat

Thank you for your guidance. Could you tell me why we do not need loop for different time steps. I also attached my geometry in which the locations of 2 plasmas are shown. Should I add one more if, to add the second plasma? Thank you very much for you time.

in your original code there was no lopps for different time steps. There was loop over faces of domain (which is not needed here and was implemented in wrong way. For more information look into Ansys Fluent Customization manual)

Macro DEFINE_SOURCE contains cell and thread as arguments, so using this macro you define source value on each specific finite volume element of mesh. Loop over elements is not needed.

You may add as many locations, as you want. In your first code coordinate values were exactly same, that's why I've deleted second IF statement

best regards