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-   -   Temporal discretisation in interFoam (http://www.cfd-online.com/Forums/openfoam/67619-temporal-discretisation-interfoam.html)

sebonator August 20, 2009 16:24

Temporal discretisation in interFoam
 
Hi everyone,

I am writing my Bachelor-Thesis at the moment and need an information about the way time is integrated by the interFoam solver for the basics-chapter of my thesis.

I already spent a lot of time for searching the User- and Programmer-Guides, but all I found are the several possibilities to perform the time integration. What I want to know is: Which of the possibilities is really used by the interFoam solver?

The three possibilities are listed in the Programmer-Guide:
-Euler implicit
-Euler explicit and
-Crank-Nicholson

The only thing I found is the possibility to choose the time derivative in the fvSchemes dictionary, but I could not find a place to choose the way time integration is performed.

I think the answer is located within the PISO loop that is called by interFoam, but I searched every source I could think of and did not find the answer to my question.

Greetings Sebastian

ngj August 21, 2009 05:43

Hi Sebastian

For interFoam, the momentum equation is discretized in time using the schemes chosen in fvSchemes by either

default ....

or

ddt(rho,U) ....

With respect to the gamma-equation it is solved using explicit Euler if you use the standard interFoam. It can be recompiled to use input from fvSchemes, i.e. implicit time integration; threads can be found on the forum on this topic.

Best regards,

Niels

sebonator August 21, 2009 08:39

Thanks ngj!

This was exactly what I wanted to know!

Greets Sebastian


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