MFIX- Hybrid model

[mcsk2000]

I would like to confirm the fact given in the following post.

Treatment of free surface flow or even 3-phase flow

Hi, i am new to MFIX and really appreciate the open source community! I want to model something similar to wet ball milling (for recycling application - but without wear or breakage consideration though). So, my model will contain a rotating drum in which I will have glass balls (DEM) and parts to be impacted (also DEM, second solid in the model), which are enclosed in a liquid (basically water), filling ca. 30% of the drum. So, this would either be a three phase problem (solid/solid-liquid-gas…

It may be the duplicated question.

@jmusser said that
“The hybrid model assumes the TFM phases are a solid and imposes a solids-solids drag. You would need to get into the source code and make modifications to get the outcome you want.”

Does that mean that only the solid(TFM)-solid(DEM) problem is available by the general hybrid model, but not for the liquid (TFM)-solid(DEM) problem?

Thanks in advance,
Hakun

[jmusser]

MFIX-Hybrid allows for a fluid coupled with both continuum solids and Lagrangian solids models. The continuum fluid can be a gas or a liquid, but the disperse continuum phase is always assumed to be a solids.

[galvinj]

To extend a little with what was mentioned. MFIX is nominally designed for modeling gas-solids flows in whatever framework you use. So, the TFM-TFM is targeted for gas-solids problems, which means that the physical properties, transport properties, interaction terms are describing (by default) gas-solids. Similarly for the TFM-DEM. The hybrid model added the connection between these frameworks, and so by default is for handling gas-solids systems. If you seeking to apply these frameworks to a different type of problem then it requires an understanding of that premise and the ability to appropriately modify all those aforementioned items to your system and physics (and possibly including new physics as the problem warrants). That can be done through the various user hooks, but you will not do it through the GUI at this time. A few additional caveats should also be mentioned. Since MFIX is designed for gas-solids systems a limitation exists in the solver based on the idea of solids maximum packing that should be considered; you can stretch it but it cannot be removed. The hybrid model exists but has not been supported for sometime and so also has a limited implementation (not reacting, not interpolated…).