[AliE]

Dear CFD friends,

I am going a to add the fractional step method by Kim and Moin (JCP 1985) in my FVM code (which actually has collocated PISO/SIMPLE + unstructured and body fitted grids) and I am collecting some information.

I have already experienced this method and I know it quite well. The only thing that I am missing a bit is how Rhie-Chow interpolation is implemented in such framework. I have an old code where I can argue something about it, but there is a lack of refereces and I am not 100% sure.

Have you experience with this? How do you perform this operation? (i.e. how you correct mass fluxes at faces to avoid pressure checkboarding?)

I have super clear both theory and practice in FVM, thus don't be shy, you can give me "high level" details

Thanks a lot!

[FMDenaro]

I analysed the RC interpolation in one of my paper but I did not use it as I worked in a different manner where no additional dissipation-like terms are introduced.

Have you already read this paper?

https://www.researchgate.net/publica...ar_Coordinates

[AliE]

Hi Filippo, Good sunday! Yes, I know this reference, but I do not use curviliear coordinates and it is diffucult apply it to my current implementation.

[FMDenaro]

Originally Posted by AliE

Hi Filippo, Good sunday! Yes, I know this reference, but I do not use curviliear coordinates and it is diffucult apply it to my current implementation.

Try to read the guide of openfoam where the RC is introduced and the references they cite. Of course, also the Ph thesis of H. Jasak should detail the interpolation on unstructured grid.


Some further papers
https://core.ac.uk/download/pdf/25787519.pdf
https://onlinelibrary.wiley.com/doi/...2%3E3.0.CO;2-X

[AliE]

Thanks, I wiil! I know well the OF interpolation used with PISO alghoritm and actually I have the same in my PISO solver.

Looking at one of my old codes using FSM, I have found out a different implementation and this makes me think that maybe the things are not exactly the same using fractional step. But maybe they are not that much This why I am curious to know other users'opinion on this topic!

[FMDenaro]

Originally Posted by AliE

Thanks, I wiil! I know well the OF interpolation used with PISO alghoritm and actually I have the same in my PISO solver.

Looking at one of my old codes using FSM, I have found out a different implementation and this makes me think that maybe the things are not exactly the same using fractional step. But maybe they are not that much This why I am curious to know other users'opinion on this topic!

As I wrote before, I developed a different procedure, however the R-C interpolation extended to unstructured grids was described here
https://www.sciencedirect.com/scienc...2199910096546X