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-   -   2d axisymmetric with swirl (http://www.cfd-online.com/Forums/openfoam-solving/60539-2d-axisymmetric-swirl.html)

 heather June 9, 2005 06:51

Hi, I'm attempting to creat

Hi,

I'm attempting to create a 2d axisymmetric (grid) with swirl case, for use with interFoam. I've created a simple geometry of a 5deg sector of a cylinder, one cell thick. The initial volume fraction is zero everywhere.

Boundary conditions:
- imagine a rectangle: left = inlet, right = pressure, top = wall, bottom = empty (axis)
- front and back boundaries declared as cyclic

Looking at the engineSwirl apps. I can see how to introduce the initial swirl (have added the swirl axis, point through which the axis passes, and a swirl component - defined as a frequency in Hz, to determine a volVectorField due to the swirl contribution). However - how do I include the swirl component in the equation set (for run-time calcs, not just initial U field setting)? - the swirl component is static wrt time.

Also - now that all cells have an associated constraint due to the boundary condition set, I'm getting the error message:

--> FOAM FATAL ERROR : Cannot find a cell not on a constraint boundary starting from cell 0

- Any ideas of how i can get around this - only route I can see is to include additional layers of cells?

Many thanks,

Andy

 henry June 9, 2005 06:58

The code will naturally calcul

The code will naturally calculate the swirl component alond with the other two components of velocity.

The error message is a consequence of bugs in the current implementation of cell-constraints which do not work correctly on constraint boundaries. Do you have a pressure boundary condition at the outlet? If so the cell pressure constraint won't be used anyway and you can remove the check which causes the fatal error.

 hjasak June 9, 2005 06:58

They boundary type on front an

They boundary type on front and back should be "wedge", not "cyclic".

Hrv

 heather June 9, 2005 07:37

Thanks for the help - all work

Thanks for the help - all working nicely

 olivier July 28, 2005 17:17

hi when front and back are w

hi
when front and back are wedge I have this message:
------------------------------------------------
--> FOAM FATAL ERROR : wedge does not align with a coordinate plane

Function: wedgePolyPatch::wedgePolyPatch(const polyPatch&, const fvBoundaryMesh&)
in file: meshes/polyMesh/polyPatches/basicPolyPatches/wedgePolyPatch/wedgePolyPatch.C at line: 75.
-------------------------------------------------
what does mean this ERROR?
Thanks for the help!

 henry July 28, 2005 17:20

The way in which wedge patches

The way in which wedge patches should be constructed is described in the documentation, please check that your mesh conforms to these rules and by reading them you will understand what the error message means.

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