What is really written out as the solution_inlet_comp_XXX?

CADET Troubleshooting
1

Hey everyone,

CADET version: reproducible on 3.1.2 (self compiled linux) and 4.1.0 (pre compiled windows)

I’m currently struggling with an unexpected behavior: I have a 3-UO system (Inlet -> Column -> Outlet) with one switch connected as [0, 1, -1, -1, flowrate, 1, 2, -1, -1, flowrate].
I would expect the outlet of UO0 to be identical to the inlet to UO1, but they deviate (see graph below).

Now my question is: is this expected or unexpected? Is the solution_inlet_comp_001 actually the input stream into the column or is it something like the top slice of the column (which could explain that added delayed peak in the appended graph)?

Thank you for your time & best wishes,
Ron

5cv
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1 Like
2

What is returned as SOLUTION_INLET_COMP_XYZ is actually the concentration in the first finite volume cell of the column. It is not the concentration of the stream entering the column.
In this context, a small delay and some dispersion is expected.

Unfortunately, this behavior is inconsistent and not very useful. I guess, it would be better to return the concentration of the inlet stream.

3

Good to know. That solves the confusion. Thank you for the quick help!

4

This has been fixed in f5129e8. Now the inlet always returns what enters the column and not the solution of the first cell. This can still be accessed when reading solution_bulk of the column.