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Controller / Excel Unit Operation compatibility

PostPosted: 07 September 2017, 09:27
by PierreO
Hello,

It seems to me that Excel Unit Operation and Controller have some incompatibilities (at least on my computer).

When I try to act on a "FlowConstraint" through a "Controller" with an outlet parameter computed from "Excel Unit Operation":
- The computed residual is always the same
- The following error message appears: "Jacobian shows its solution is not unique".

I can observe this on a mathematically simple problem which has for sure a unique solution (see attached file).

Did I used the controller in a wrong way? Or are these blocks incompatible?

Re: Controller / Excel Unit Operation compatibility

PostPosted: 07 September 2017, 11:20
by jasper
Looks like your sheet does not calculate, because automatic calculation was turned off. Turn it back on, and you should no longer see that the Jacobian is singular and the controlled stream is undefined (as without calculation, the measured variable does not depend on the controlled variable).

Note that the solution of your problem is at an infinite flow rate, which clearly will pose another problem.