# rRb definition in SchnerrSauer phase change model

I'm dealing with a cavitation problem and started digging in the source code of phase change models available with the interPhaseChangeFoam solver.

While checking the rRb definition in the Schnerr and Sauer model:

```
return pow
(
((4*constant::mathematical::pi*n_)/3)
*limitedAlpha1/(1.0 + alphaNuc() - limitedAlpha1),
1.0/3.0
);
```

I've noticed the volume fraction of the liquid is used instead of the vapor one as in the definition of bubble radius from theory.

I feel like this would be too obvious to be an error/bug, so I was wondering what am I missing.