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Unknown variables

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The software shows that a variable I defined contains an unknown variable, but this unknown variable is the electric potential V, a dependent variable of the electric current interface, which means it cannot be written as a specific expression to define it. So how can i solve this problem? I will be appreciated to receive replies!


1 Reply Last Post 1 sept. 2022, 13:32 UTC−4
Jeff Hiller COMSOL Employee

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Posted: 2 years ago 1 sept. 2022, 13:32 UTC−4
Updated: 2 years ago 2 sept. 2022, 08:38 UTC−4

The most likely scenario is that you are trying to call the variable outside of its geometric scope. For instance, that can happen if V is defined in one region and you're calling it in another, or it's defined on some boundaries and you're trying to use it in a domain, or in a global expression when it is a field, etc...

If that's not the case, please post your .mph file to this thread so participants to this Discussion Forum can chime in productively (It's hard to give more than educated guesses without seeing how you have set things up!).

Best regards,

Jeff

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Jeff Hiller
The most likely scenario is that you are trying to call the variable outside of its geometric scope. For instance, that can happen if V is defined in one region and you're calling it in another, or it's defined on some boundaries and you're trying to use it in a domain, or in a global expression when it is a field, etc... If that's not the case, please post your .mph file to this thread so participants to this Discussion Forum can chime in productively (It's hard to give more than educated guesses without seeing how you have set things up!). Best regards, Jeff

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