Learning Forum

[AnthonyB08]

Hi all,

 

I am simulating a transient counter flow packed bed stripper, gas-liquid, with several sourced momentum terms. One is a liquid dispersion where a drift flux model is incorporated, see image below.

 

My question is when I initialize a multiphase model, I believe I cannot initially set both phases to a vof of 0 in the domain ( signifying empty). To counter this issue is it logical to add an inert phase, say air, to occupy the domain as the liquid and gas purge through the system?

 

Context: If I initialize with the gas occupying the domain my sourced momentum term causes instability in the simulation. Whereas, if I make the liquid occupy the domain initially the vof residual of the gas phase is 0. 

[Rob]

What is the purpose of the simulation? You're correct in that the system must be full of something, but that something could be inert gas (species mixture with the other gas in the same phase) or just gas, just liquid or a mix based on the expected volume fraction.