negative volume found in grid

[Mubashir Ali]

I made a grid whose domain is spherical using my own code to run it on code saturne and fluent. the grid is running absolutely fine on Fluent but the same grid when i run on code saturne .. it gives an error stating negative volumes.

Procedure of creating the grid:

1) Using Hyperbolic Partial Differential Equations – Steger, Chaussee, I create a 2D grid for the airfoil housing.

2)  Next i rotate the grid around the axis of symmetry to make it a 3 D grid keeping in mind that cells on the aixs of symmetry would be prism cells.

3) the 3 D grid is written in neutral file format including the boundary conditions, which is accepted by Fluent and code saturne

I am attaching the listpre file wiht this email

Kind Regards

Mubashir

[Yvan Fournier]

Hello,

Do you really rotate the grid or do you apply symmetry ? If you apply symmetry, it is probable that your local cell->vertex connectivity is inverted. To fix this, simply use the --reorient option for the Preprocessor (also available in the GUI).

This option is not enabled by default, as it may be difficult to distinguish badly oriented cells from highly warped cells, but in the case of a good quality mesh, it works fine.

Best regards,

  Yvan Fournier

[Serra Sylvain]

Hello,
 
I had the same problem on meshes created with Gambit.
 
I did not found solutions until the installation of the last version of Code_Saturne (V2.0.1).
Thank to this version, the same mesh works without any problem...
 
Sylvain

[Mubashir Ali]

@ Yvan  
I really rotate the grid. I make first 2D grid (half circle)  and then I rotate it around the axis (body is axis symm) to obtain a 3D grid with spherical domain.
I am using version 1.3 ... unfortunately i did not find any reorentiation tab in GUI :( 
 
@ Sylvain
 
Thnx for the info .... if this 1.3 version does not work ... will try to install V2.0.1  :D