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UDF to read cell var. based on particle position

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Old   January 27, 2014, 12:02
Default UDF to read cell var. based on particle position
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Cees Haringa
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Hello all,

I'm currently working on a routine to read local tracer gradients, based on particle position; so globally:

- Read in which cell C particle P resides at timestep T
- Update user defined scalar to take the value of C for particle P

I don't have any experience on writing UDFs (The ANSYS tutorials show how to use them, but not how to write them.) but expected the routine to be very much like the DPM_SCALAR_UPDATE macro supplied in the UDF manual.

However, when I try to literally copy this routine:

cphase_state_t *c = &(p->cphase);
p->user[0] = 0.;
viscosity_0 = c->C_YI(i);

with i the component index I want to read; it gives the error C_YI is not defined in cphase_state.
If I use

conc_0 = c->yi[i];
p->user[0] = conc_0;

The routine runs, but the output is always zero.
Probably I'm just doing something stupid, based on my lack of UDF/C programming knowledge, but I'm a bit lost in how to continue/where to look.
For example, I cannot find any comprehensive list containing accessible and variables and structures; does anybody know where to find such a list?
And of course, any ideas on how to read the local concentration would be much appreciated.

Thanks in advance!
Cees
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Old   February 3, 2014, 12:14
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Quote:
Originally Posted by CeesH View Post
- Read in which cell C particle P resides at timestep T
cell_t c = P_CELL(p);
Quote:
Originally Posted by CeesH View Post
- Update user defined scalar to take the value of C for particle P
Do you really mean user defined scalar, and not user defined memory? If you mean user defined memory:
P_USER_REAL(p,0)=C_YI(c,t,0)

It is not much, but maybe it can help you a bit.
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Old   February 24, 2014, 11:21
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Cees Haringa
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Hello Pakk,

C_YI(c,t,0) was indeed the function I needed, thanks!
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