[allenpv]

I have set up a multiphase model in Fluent with 2 phases (gas and liquid nitrogen)

I created a region in Adapt>Cell Registers>New Region

I used Save/Display to see the defined region and everything looks good

I initialized the domain using standard method with phase2 (liquid) volume fraction as 0 over the entire domain

I then patched phase2 (liquid) volume fraction as 1 in the defined region. Please find attached screenshot of this step. Please note that I have only selected the region and I have not selected the zone. I get the message (certain number of cells have been marked).

Next to verify if the patching was done correctly, I created a contour to show the volume fraction of phase2 (liquid) but the result shows the whole domain having 0 volume fraction (implying that the region patching did not work). There are no error messages.

Attached Figures:

Fig 1: Region created in Cell Registers and displayed
Fig 2: Patching region with phase2(liquid) volume fraction 1
Fig 3: Contour showing the whole domain have initial volume fraction value and patching did not take place

[allenpv]

I was able to fix this by using the marked region to separate the single cell zone within Mesh>Zone>Seperate

Once I had two cell zones, I patched each zone with respective values of phase volume fraction and I could observe the result in the initial contour.

This however still does not explain why I couldn't achieve the same result just by patching the region. Confused (maybe a bug?).