[philipxyz]

Hi,

I'm currently simulating a multiphase flow in 2 phases with pbm. phase 1 is gasoline and phase 2 is water. The goal is to simulate an emulsification process with water as the dispersed phase.
As my multiphase model I'm using the Euler and Mixture model to compare them. (see attached screenshots)

In the beginning I was simulating the flow without any PBM activated, just So I know that it is running stable. The Problem is that as soon as I activate the PBM my flow pattern changes completely, while it is still running stable and converging.

So the question is if anybody knows why the flow pattern changes or how to fix it.

Thank you

[DCT]

That looks rather odd. Is the simulation in 2D? And are the droplet sizes with the PBM comparable to your earlier solution? Did you set boundary conditions (incl. inlet droplet size) properly?

[philipxyz]

Originally Posted by DCT

That looks rather odd. Is the simulation in 2D? And are the droplet sizes with the PBM comparable to your earlier solution? Did you set boundary conditions (incl. inlet droplet size) properly?

The simulation is in 3D, the screenshot is on a plane.

I hope my BC are set properly. I've followed the fluent theory guide. I have two velocity inlets and a pressure outlet.
Walls etc. are set properly.
I haven't changed any conditions on the two simulations except activating the PBM.

[DCT]

can you show a plot of droplet sizes compared to see how they compare to earlier settings? And how are the residuals doing, is everything converging?

[philipxyz]

Originally Posted by DCT

can you show a plot of droplet sizes compared to see how they compare to earlier settings? And how are the residuals doing, is everything converging?

Thank you for your help.
In the meantime I solved or rather know what the problem is. I just didn't anticipate the amount of changes that come in top play with different bin sizes, like drag and non-drag forces, surface tension etc.