CFD Online Discussion Forums - Using a C_UDMI defined in one UDF in another UDF

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Using a C_UDMI defined in one UDF in another UDF

I use a C_UDMI to calculate the number of particles that deposit on a wall as:

DEFINE_DPM_BC(Deposition,p,t,f,f_normal,dim)
{
#if !RP_HOST
Thread *tcell=P_CELL_THREAD(p);
cell_t c=P_CELL(p);
Domain *d;
d=Get_Domain(1);
C_UDMI(c,tcell,0) += 1.;
return PATH_ABORT;
#endif
}

Then, I want to use this C_UDMI in another UDF to move the mesh where particles are deposited:

DEFINE_GRID_MOTION(beam,domain,dt,time,dtime)
{
Thread *tf;
face_t f;
int n;
Node *v;
/* get the thread pointer for which this motion is defined */
tf=DT_THREAD(dt);
begin_f_loop(f,tf)
{
f_node_loop(f,tf,n)
{
v = F_NODE(f,tf,n);
......
......C_UDMI.......
......
}
}
end_f_loop(f,tf);
}

Is this possible? Can anyone help how to do this?

Thanks,

real G;
G=C_UDMI(c,t,0); will allow you to use it on another define macro

but above you are trying to use cell data in face node loop. You cant transfer data like that

Thanks for your response. So does G have all information that C_UDMI has?(cell information and stored values)
Do I need to define G in the second UDF as well? Something like:

DEFINE_GRID_MOTION(beam,domain,dt,time,dtime)
{
Thread *tf;
face_t f;
int n;
Real G

....

Quote:

Originally Posted by sthinmind (Post 687196)

I use a C_UDMI to calculate the number of particles that deposit on a wall as:

DEFINE_DPM_BC(OSU_Deposition_Model_R1,p,t,f,f_norm al,dim)
{
#if !RP_HOST
Thread *tcell=P_CELL_THREAD(p);
cell_t c=P_CELL(p);
Domain *d;
d=Get_Domain(1);
C_UDMI(c,tcell,0) += 1.;
return PATH_ABORT;
#endif
}

Then, I want to use this C_UDMI in another UDF to move the mesh where particles are deposited:

DEFINE_GRID_MOTION(beam,domain,dt,time,dtime)
{
Thread *tf;
face_t f;
int n;
Node *v;
/* get the thread pointer for which this motion is defined */
tf=DT_THREAD(dt);
begin_f_loop(f,tf)
{
f_node_loop(f,tf,n)
{
v = F_NODE(f,tf,n);
......
......C_UDMI.......
......
}
}
end_f_loop(f,tf);
}

Is this possible? Can anyone help how to do this?

Thanks,

Yes, it is possible. It is even simpler than your code.

In your UDF "OSU_Deposition_Model_R1", you now store face data in a C_UDMI, by first finding the associated cell. You can skip that step, and directly store it in F_UDMI(f,t).

Code:

DEFINE_DPM_BC(OSU_Deposition_Model_R1,p,t,f,f_normal,dim)

{

#if !RP_HOST

F_UDMI(f,t,0) += 1.; 

return PATH_ABORT;

#endif        

}

And in your other code, you can simply extract the data with F_UDMI(tf,t).

Thanks for your response.

I guess I need the nodal values in DEFINE_GRID_MOTION to move the mesh? How do I store the same value (F_UDMI) in the neighboring nodes? How do I find the nodes around a the face f? (In 2D there are two nodes at two sides of the face)