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Value of dependent variable at a point as boundary condition at another edge

Sherif Lotfy Abdelaziz

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Hi,

I am wondering if COMSOL allow us to assign the value of a dependent variable at a point as a boundary condition at an edge away from the point? This will help me understand if COMSOL can fit my needs or not so I will decide to buy it or not.

I will be using this with time dependent solver solving for temperature distribution inside a tube where the inlet boundary condition is, for example 5 degree F more than the outlet. Therefore, I will start with an initial condition at the inlet, calculate the outlet, then use this calculated value to change the boundary condition at the inlet and so on. Please help.

I have a trial version and would like to make sure that COMSOL meets my needs before buying it.

Thanks
Sherif

2 Replies Last Post Jul 20, 2011, 12:55 p.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Nov 8, 2010, 9:08 a.m. EST
Hi

first of all you can also get help from the official support ;)

Cehck the coupling variables, this does normally allow to get average or integrated values from one part of the model looped back to another point/place.

There is the thermal wall example in 3.5, but I'm not sure its already ported to V4

--
Good luck
Ivar
Hi first of all you can also get help from the official support ;) Cehck the coupling variables, this does normally allow to get average or integrated values from one part of the model looped back to another point/place. There is the thermal wall example in 3.5, but I'm not sure its already ported to V4 -- Good luck Ivar

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Posted: 1 decade ago Jul 20, 2011, 12:55 p.m. EDT
Hi Ivar,

I was able to do this in COMSOL 3.5a. But now I updated my COMSOL to the latest 4,2 version and spent so much time trying to do the same but unsuccessful. Do you have any idea how to use the coupling variables in COMSOL 4.2, if any?

Sherif
Hi Ivar, I was able to do this in COMSOL 3.5a. But now I updated my COMSOL to the latest 4,2 version and spent so much time trying to do the same but unsuccessful. Do you have any idea how to use the coupling variables in COMSOL 4.2, if any? Sherif

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