Which model is best suited for a problem with mixing of two liquids? Is it the VOF model? Regards Jan

What are these fluids and how do they mix in real life?

It is two liquids with a density difference. They have the same inlet and are flowing into a kind of a settling chamber. The liquids can mix and none of them are droplets/dispersed. I tried to look at calculation the problem with specie transport but that approach seems for mixing of gas. I also looked at the multiphase models, but for the mixture and euler model a diameter need to be specified which confuses me a bit. The VOF model gives a bit strange results.

Hi,

In VOF model, are you solving in steady state or transient state?

Transient analysis is recommended for VOF model. What discretization method is used for pressure and momentum?

with regards, JSM

It is a steady state problem. The problem with the VOF model is that I have both fluids at the same inlet and I think that it is a violation of the VOF model. I can get results with the mixture model, but both fluid are continues and I dont like the idea of defining a size for one of the phases.

Hi jan,

If both fluids are immescible fluids, then you can proceed with VOF model. If both fluids are homogeneous mixture, then you can use mixture model with disabling the slip velocity option. It will ensure the homogeneous mixture. You need not to specify the diameter of secondary fluid.

Could you explain in detail about your application and set up of your simulation.

with regards, JSM