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Integral variable

Posted 15 mag 2023, 05:54 GMT-4 General, Chemical Reaction Engineering, Modeling Tools & Definitions Version 6.1 2 Replies

Lasse Murtomäki
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I have defined a variable, call it Cout, that is the integral concentration of a solute at the exit of a reactor channel. When I try to use that variable in the model, the message appears that the variable Cout is unknown. Yet, after simulation I can evaluate its value.

Some 10 years ago I did the same for maintaining the mass balance, no problem.

What's going on?

2 Replies Last Post 16 mag 2023, 02:36 GMT-4
Jeff Hiller COMSOL Employee

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Posted: 2 years ago 15 mag 2023, 08:35 GMT-4
Updated: 2 years ago 15 mag 2023, 08:38 GMT-4

Hi Lasse,

Two possibilities come to mind:

1/ Maybe you defined Cout in the Results part of the Model Builder, in which case it's defined solely for postprocessing purposes. If that's the case, define it via Probes or Nonlocal Couplings under Definitions instead.

2/ If you did define Cout under Definitions, make sure that you made its scope global so that it is available where you need to use it.

Best,

Jeff

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Jeff Hiller
Hi Lasse, Two possibilities come to mind: 1/ Maybe you defined Cout in the Results part of the Model Builder, in which case it's defined solely for postprocessing purposes. If that's the case, define it via Probes or Nonlocal Couplings under Definitions instead. 2/ If you did define Cout under Definitions, make sure that you made its scope global so that it is available where you need to use it. Best, Jeff
Lasse Murtomäki
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Posted: 2 years ago 16 mag 2023, 02:36 GMT-4

Thanks for a prompt reply!

That was it. I changed the variable to 'Entire model' under Definitions. It was only the Boundary.

Thank you Sir.

Thanks for a prompt reply! That was it. I changed the variable to 'Entire model' under Definitions. It was only the Boundary. Thank you Sir.

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