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-   -   Philosophy of implicit solution of different regions (http://www.cfd-online.com/Forums/openfoam/68886-philosophy-implicit-solution-different-regions.html)

Louis Le Grange October 5, 2009 10:53

Philosophy of implicit solution of different regions
 
Hi

I have a few questions in this regard;

1) What happened to the coupledMatrix source directory from previous versions to 1.6? Or was it only available in previous -dev releases? Will the coupledMatrices appear again in a 1.6-dev?

2) It seems to me that the philosophy in OpenFOAM regarding say the solution of the energy equation in different materials is to treat each material separately as far as possible and then also solve it seperately as in a parallel case - with updating of the material interface fluxes or boundary conditions between iterations. I can see some advantages in this regarding the object orientated aproach. Am I right in my perception?

3) Is there perhaps a study available on the considerations on whether to solve different regions implicitly in 1 matrix or seperately sequential or parallel for that matter, ito convergence, speed, convenience, etc?

4) I have experience of certain solid-fluid problems that needs to be very closely coupled in terms of temperature such as counter-current heat exchangers. In such cases it is virtually impossible to get convergence (even given an implict temperature 1-matrix solution method) using standard iterative numerical solution methods such as a bicg-method - special measures are needed such as direct solution methods. If my understanding in 2) is correct - would the seperate solution of the different materials not be even further detremental to the success of solutions to the problem stated in 4)?

Thanks in advance,
Louis


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