Learning Forum

[Bart]

In the description of define linearized mass transfer, the source term is processed as follows:

I am curious about the expression of k1 and k2. If the source term is not proportional to afrom or ato, how to determine the expressions of k1 and k2. For exmple, the source term of Schnerr and Sauer cavitation model is proportional to a*(1-a). What the expression of m_dot is?

For example, I have written a code.

c_evap = 3.*F_evap*rho_l*rho_v/(rho_mix*RB);

m_dot = c_evap*sqrt((2/3.0)*dp/rho_l)*(1-vof_v);

m_source = m_dot*vof_l;

It didn't work. As i removed the term "(1-vof_v)" in Line2, it was feasible, but I knew it was wrong.

I hope someone can give some advices.

Thanks!

 

[Bart]

I am not sure whether k1 or k2 means dS/da (or dS[eqn]). If so, does m_dot and m_source mean dS/da (or dS[eqn]) and source (S) respectively?

[Amine Ben Hadj Ali]

The example in the manual is providing a good explanation how to derive those linearization parameters.

[Bart]

Thanks for your reply!

The example in the manual is provided for ZGB cavitation model, but in this model the source term is proportional to volume fraction which is different from that in Schnerr-Sauer model. I didn't find detailed information of derivation of  those linearization parameters in the panel of DEFINE_LINEARIZED_MASS_TRANSFER. I am not sure that this derivation is similar to that in the panel of DEFINE_SOURCE.

Kind regards.

[Amine Ben Hadj Ali]

The docu does provide how to derive in the example of ZGB. With Schnerr-Sauer should not be much different. Do not forget that for two phase vof_l=1-vof_g.

If you have difficulties to provide the linearization then use DEFINE_MASS_TRANSFER