Coupled degrees of freedom

[ABasak]

Hello,

Is there any keyword for coupling any given degrees of freedom over a selected group of nodes?

Abhishek

[raback]

Hi, there are many ways by which dofs may be coupled. Could you be more specific what you mean. -Peter

[ABasak]

Hello,

Suppose that I am solving a thermal conduction problem, and I have to ensure that the temperature of all nodes on a given region are the same, so I can couple the temperature degrees of freedom for these group of nodes. Is it possible?

In the Elmer Solver Manual, there is an article on Linear Constraints, but no example.

Regards
Abhishek

[raback]

Hi

I'm not either familiar with using the linear constraint solver. I think tutorial 25 deals with an example. There is also an alternative "coupled solver" approach which allows for all kinds of constraints and strong coupling of different equations in different regions. This is alternative to the main weak coupling loop and hasn't been much pursued but you can find CoupledSolver* examples in the tests directory. Unfortunately the examples are related to just a simple Poisson equation.

Perhaps it would be an option to describe just a really high thermal conductivity to the region where these nodes are, to ensure that they get roughly the same value.

-Peter

[ABasak]

Hello,

Is there any example problem for tutorial 25??? ..... I don't think giving large thermal conductivity will solve the issue, as it might lead to stiff matrices...

Abhishek