CFD modeling of O2 dissolution in water
 

Hello,



I am simulating O2 dissolution in water in a mixing tank. In the simulation of mass transfer, I have some doubts about some parts that might have sth to do with the model not working properly.

1- I am having two mixtures, one is (O2, N2) as gas and the other one is (O2, water) as liquid phase. For creating the mixtures I used the same O2 that is in the gas phase in my liquid mixture. (I found out this is the right way instead of using liquid O2). So now my questions are:

-Do I have to change the density of the O2 in the liquid phase? or leave it as it is?

-Which model do I use for the density of the mixture, I am using Compresible-volume-weighted-mixing-law, is that proper model to use?



2-In mass transfer modeling I am choosing species-mass-transfer model from O2 gas to O2 in liquid, and then I am choosing Henry's law for equilibrium.

-I am not sure what to enter for Molar fraction correlation (Pa) ??

Then I choose overall mass transfer coefficient and compile a mass transfer UDF based on higbyes penetration theory .

-the Udf I am using gives KL (1/m2S)* cell volume since the unit is m/s, is that correct?

I would appreciate it if anyone can help me figure out if my steps are correct or what can I do differently.



Thanks,