[AlxB]

Dear Foamers,

depending on the mesh, I often gets this createNonConformalCouples Maximum openness Fatal Error despite the mesh improves: how to get rid of it? is the maximum openness tolerance manageable in a dictionary ?

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  13
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
Build  : 13-cde978a97c93
Exec   : createNonConformalCouples nonCouple1 nonCouple2
Date   : Oct 05 2025
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Adding nonConformalCyclic interfaces between patches: 
    (nonCouple1 nonCouple2)
In regions: 
    (region0 region0)
Named:
    (nonConformalCyclic_on_nonCouple1 nonConformalCyclic_on_nonCouple2)
With transform: 
    transformType   none;

patchToPatch: Calculating couplings between ...
    source patch nonCouple1 with 5935 faces and ...
    target patch nonCouple2 with 5935 faces
    Source min/average/max coverage = 1/1/1
    Target min/average/max coverage = 1/1/1
    Source average openness/error/depth/angle = 6.6739792e-17/3.5896548e-13/6.6417338e-15/2.6364017e-07
    Source max openness/error/depth/angle = 4.4006583e-16/1.175864e-10/4.7760787e-13/1.7075473e-06
    11870 couplings calculated in 2.118642s
fvMeshStitcher: Connecting
    Cell min/average/max openness = 0/2.2793813e-10/1.946623e-06


--> FOAM FATAL ERROR: 
Maximum openness of 1.946623e-06 is not tolerable

    From function bool Foam::fvMeshStitcher::connectThis(bool, bool, bool)
    in file fvMesh/fvMeshStitchers/fvMeshStitcher/fvMeshStitcher.C at line 1827.

FOAM exiting

thank you in avance for your help