Learning Forum

[gloria.gonzalez]

I am trying to build a UDF that models the mass transfer between the particles (DPM model) and the surrounding medium. For that purpose, I need to define as variables the medium density and the concentration of a certain species in the particle and the surrounding medium. What are the appropriate macros to do so? I am trying with:

Medium density: C_R (c, t)
Species concentration in the medium: C_YI (c, t, 0)
Species concentration in the particle: TP_COMPONENT_I (tp, 0)

Is this correct?

Then, how should I define the thread t in the case of the medium? This is giving me some problems. I have tried to use t, defined as Thread * t = TP_CELL_THREAD(tp), but Fluent points out that the index is not valid for C_R and C_YI. 

I have seen in an example in the User’s Guide the following definition: Material *gas_mix = THREAD_MATERIAL(DPM_THREAD(t0, tp)), but I cannot understand its meaning and utility. Could anybody clarify it?

Any reply will be appreciated. Thank you in advance!

[Rob]

The example for DEFINE_DPM_HEAT_MASS will get you the transfer mechanisms. There's also a section in there real cvap_bulk.... that may give you an idea for density.  The various DPM models aren't always very easy to get working together using UDFs, and as mentioned before our ability to offer UDF support is very limited.