Inflation and multiphase can be an interesting discussion. Whilst I can't go into too much detail consider the effect of particles/bubble that are bigger than the near wall cell height. How does that compare with your y+ theory?
Check the Learning AIS content and also the newer Knowledge Materials, https://ansyskm.ansys.com/ The latter are "public" versions of the Customer Portal content, and I'm fairly sure I saw some mention of bioreactors when checking the materials.
You are navigating away from the AIS Discovery experience