Courant in axisymmetric simulations
Hi foamers
I am currently trying to simulate an axissymmetrical setup using wedge. Because of the wedgelike shape, some cells become very small. I tried to solve this using the simpleGrading which makes the cells near the axis longer (in rdirection) than the cells further away from the axis. However, I still get very long calculation times. Is there any other method which I can apply to reduce the calculation time? I am using a wedge of 1°, so the cells are also very thin. I could increase this to 5 degrees, but I am not sure whether:  the calculation time will decrease significantly?  this has any influence on the accuracy of the simulation? Thank you in advance Best regards Arne 
Is your mesh 2d, or 3d? What does meshCheck say?

Hi yambanshee
Thank you very much for your reply. My mesh is 2D, which I thought was obligated when using the wedgeboundary conditions? I did not try checkMesh yet, my mesh works since the calculations run, they just run very slowly because of the Courant Number in the cells at the axis. I will try checkMesh immediatly and I will let you know the results. Best regards Arne __________________________________________________ __________________________________________________ ________________________________ EDIT: I just tried checkMesh and he results are below. This mesh was made with blockMesh and had a simpleGrading of (1 1 1). /**\  =========    \\ / F ield  OpenFOAM: The Open Source CFD Toolbox   \\ / O peration  Version: v1806   \\ / A nd  Web: www.OpenFOAM.com   \\/ M anipulation   \**/ Build : v1806 Arch : "LSB;label=32;scalar=64" Exec : checkMesh Date : Mar 06 2019 Time : 09:26:36 Host : "ea10c417" PID : 672 I/O : uncollated Case : /mnt/c/Users/arsimons/Documents/OpenFOAM_local/simulaties/AA_Geometry/Wedge nProcs : 1 trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE). fileModificationChecking : Monitoring runtime modified files using timeStampMaster (fileModificationSkew 10) allowSystemOperations : Allowing usersupplied system call operations // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Create mesh for time = 0 Time = 0 Mesh stats points: 20301 internal points: 0 faces: 40050 internal faces: 19750 cells: 10000 faces per cell: 5.98 boundary patches: 6 point zones: 0 face zones: 0 cell zones: 0 Overall number of cells of each type: hexahedra: 9800 prisms: 200 wedges: 0 pyramids: 0 tet wedges: 0 tetrahedra: 0 polyhedra: 0 Checking topology... Boundary definition OK. Cell to face addressing OK. Point usage OK. Upper triangular ordering OK. Face vertices OK. Number of regions: 1 (OK). Checking patch topology for multiply connected surfaces... Patch Faces Points Surface topology axis 0 0 ok (empty) rightWall 200 402 ok (nonclosed singly connected) lowerWall 50 101 ok (nonclosed singly connected) atmosphere 50 101 ok (nonclosed singly connected) back 10000 10251 ok (nonclosed singly connected) front 10000 10251 ok (nonclosed singly connected) Checking faceZone topology for multiply connected surfaces... No faceZones found. Checking basic cellZone addressing... No cellZones found. Checking geometry... Overall domain bounding box (0 0 0.0174) (0.05 0.2 0.0174) Mesh has 2 geometric (nonempty/wedge) directions (1 1 0) Mesh has 3 solution (nonempty) directions (1 1 1) Wedge back with angle 19.1879 degrees Wedge front with angle 19.1879 degrees All edges aligned with or perpendicular to nonempty directions. Boundary openness (7.25056e14 3.85576e18 1.36653e17) OK. Max cell openness = 2.21273e16 OK. Max aspect ratio = 2 OK. Minimum face area = 3.48e07. Maximum face area = 3.48e05. Face area magnitudes OK. Min volume = 3.48e10. Max volume = 3.4452e08. Total volume = 0.000174. Cell volumes OK. Mesh nonorthogonality Max: 0 average: 0 Nonorthogonality check OK. Face pyramids OK. Max skewness = 0.869726 OK. Coupled point location match (average 0) OK. Mesh OK. End 
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