AMI code enhancements

Summary

Note: this is beta-level code and will receive further updates in future releases

This change set includes:

• New option for cyclicAMI and cyclicACMI patches to perform topological updates to enforce a 1-to-1 match between source and target patches to ensure conservation across AMI patches and greatly reduced pressure field perturbations. Changes based on ref [1]
• Deprecated directAMI; replaced by nearestFaceAMI
• Significant code refactoring

Resolved bugs (If applicable)

• General AMI conservation issues/noisy pressure predictions

Details of new models (If applicable)

• Backwards compatibility [should be] maintained

• New topological changes triggered by using a special mesh motion solver: dynamicFvMesh dynamicMotionSolverFvMeshAMI;

  • this may be absorbed into the 'standard' dynamicMotionSolverFvMesh model in future releases

• Test case: mixerVesselAMI2D_with-boundary-layers.tgz

dynamicMotionSolverFvMesh	dynamicMotionSolverFvMeshAMI
v2006	v2006
v1912

Note: since the AMI code triggers topological updates, to reconstruct parallel cases:

• use reconstructParMesh to reconstruct the mesh at each time, followed by reconstructPar to reconstruct the fields; or

• use redistributePar -reconstruct to reconstruct both mesh and fields (in parallel)

• Code refactoring has enabled greater control of the AMI; the AMIMethod can now be set in the polyMesh/boundary file, e.g.

    AMI2
    {
        type            cyclicAMI;
        inGroups        1(cyclicAMI);
        nFaces          96;
        startFace       6336;
        matchTolerance  0.0001;
        transform       noOrdering;
        neighbourPatch  AMI1;
 
        // New optional entries
        AMIMethod       faceAreaWeightAMI;
        restartUncoveredSourceFace 1;
    }

Deprecations

The directAMI method has been deprecated and replaced by the faster and more robust, new nearestFaceAMI method. The new method creates a 1-to-1 mapping based on the nearest face.

Risks

• Significant change to AMI code
• Not only affects cyclic patches, but other areas of the code that make use of the tooling, e.g.:
  • mapped patches
  • mapFieldsPar
  • region models (film modelling)
  • mapping function objects

Known issues/to check

When using dynamicMotionSolverFvMeshAMI

• restart behaviour not currently available

Tests

Checked on the following cases:

• pimpleFoam/laminar/mixerVesselAMI2D
• pimpleFoam/RAS/oscillatingInletACMI2D
• XiDyMFoam/annularCombustorTurbine
• {customer turbo machinery}

For each, the dynamicMotionSolverFvMesh option recovers v1912 behaviour

References

[1] H.J. Aguerre, S. Márquez Damián J.M. Gimenez, N.M.Nigro, Conservative handling of arbitrary non-conformal interfaces using an efficient supermesh, Journal of Computational Physics 335(15)21-49. 2017. https://doi.org/10.1016/j.jcp.2017.01.018

Acknowledgements

• Many thanks to Horacio Aguerre @aguerrehoracio and Santiago Márquez @santiagomarquezd for bringing the methodology to our attention and for many useful discussions and testing throughout these developments.