Learning Forum

[kifg]

Hi everyone,

I'm learning how to use UDRGM. So, I want to do a two-phase flow with Homogeneous Equilibrium Model (HEM). First I've created a UDF to employ an enthalpy transport equation. For this approach I was using the UDF to read the fluid properties, however, I'm with convergence problems. So, I'm thinking to use UDRGM multispecies for the properties, with lookup tables. And the UDF for the diffusivity.

And now I have two questions:

1. I need to read in the UDRGM the C_UDSI (my enthalpy), in order to obtain my properties. But, I don't know how to do it, even if it is possible.
2. My multispecies UDRGM has 2 'fluids', the lçiquid and the vapour phase. I'm confused, how FLUENT gets the yi[] value? Instead of using it, I wanted to compute the flow quality and with that interpolate in my lookup tables to get all the properties that I need. Does this make sense?

Thanks to all for the help :)

[KR]

Hello:
Here are some comments on your question.
You should be able to access the enthalpy through a cell macro. You can find this in our Customization manual.
You will need to use multi-phase specific thread to identify the primary and secondary phases. Please see the link below.
1.9.1. Multiphase-specific Data Types (ansys.com)
I hope this helps.
Karthik