Comparing "ROP" for similar cases

Hi all,
I have been working on a 3D TFM fluidized bed for some time, and now looking through the results with a more critical eye. The image below shows two different cases, the one to the right has 50% increased air flow, where I’ve created a threshold filter in Paraview, trying to see patterns in the particles fractions (there are a total of 4). However, quite shortly after startup (here, 5 seconds), there already seem to be quite a different content of the two fractions, still being filtered with the same settings. And I find this odd. Or is the ROP showing something other than I think? (I couldn’t find the definition of ROP anywhere.) Here the results are from opening the .res file (which I believe also accesses the spx files). I have stored volume fractions in VTK files, but only for sections, not the entire volume.

ROP_s is the solids bulk density = solids fraction times solids density.

If your solids density is constant, then ROP_s will look the same as the solids fraction. As you increase the air flow rate, you get larger bubbles (the clipped low values of ROP_s mean large values of the void fraction, i.e., bubbles).

Kjetil - rop is an internal MFiX variable, whenever you see ro read it as rho (ρ) which implies it’s a density. In the GUI we use more user-friendly labels but unfortunately on the output side the “raw” names get exposed. One source of help: you can use the keyword browser and type in a term or part of a term to find more info: