[Crow]

Hi,

I'm new in Fluent. I am modeling two phase flow in a pipe with VOF. I need to make an UDF for the mass transfert.

So I was wondering where I can find all the "accessible" variables when I use DEFINE_MASS_TRANSFERT and how to "call" them.

For exemple, in the UDF manual there is an exemple UDF using C_T(cell,gas). I assume it is the temperature of the cell. Where would I have been able to find the correct variable name to use it.

Thanks for your time.

[pakk]

I think you are looking for C_R(c,t), in combination with C_U(c,t), C_V(c,t) and C_W(c,t). They are the same section of the help as C_T.

[Crow]

Thanks for the reply. I didn't find what I was looking for in the help which was the interfacial area but by looking the forum I found that you could calculate it with

A_i = C_VOF_G(c,t)[0]*C_VOLUME(c,t).

which I also saw elsewhere but in continuous form.

I have two other questions:

1) Does the order of the species (0,1,2, etc) is the same as in the mixture declaration?

2) Is the from_index in
DEFINE_MASS_TRANSFER(liq_gas_source,cell,thread,fr om_index, from_species_index, to_index, to_species_index)
is the primary phase or secondary phase?

Thanks in advance

[Crow]

1)The species id is the same as shown in the mixture declaration

2) the from_species_index is the index of the species you choose to be from when you hook the function

3)Primary phase is 0,
Secondary phase is 1,
etc

4)The from index is the phase you choose when you hook the function