Phase Change Does not occur for sub-cooled boiling

[ssthakar]

I am using this wonderful library to simulate sub-cooled boiling in microchannels. I am facing difficulties in modeling the phase change. When there is no initial vapor present, I expect the temperature of the fluid to rise until eventually the cells where T > T_sat phase change occurs and bubbles are formed. I don't see this behavior. The Stephen-Welch Film boiling validation case works perfectly, but there vapor fraction is already present in the domain.
Any help is greatly appreciated.
Thank you!

[HenningScheufler]

All current implementation of the phase change mass fluxes are proportional to the interface area in the cell. So, what you are seeing is the expected behavior.

So what you can do is to create a macroModel:

https://github.com/DLR-RY/TwoPhaseFlow/tree/master/src/phaseChange/phaseChangeModels/macroModels.

You could check if the cell next to wallBoundary is superHeated and does not have an interface. If it would be the case you could specify the alphaSourceTerm and energySourceTerm to trigger the initial bubble creation

[ssthakar]

Thank you for your guidance! So I should implement something like the standard Lee phase change model ?

[HenningScheufler]

The schrage model is already implemented which is similar to the lee model. You just need to trigger evaporation with a Macro model to reduce the alpha value below 1