# [blockMesh] mesh grading problem with multiple blocks

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 December 21, 2010, 02:33 mesh grading problem with multiple blocks #1 New Member   Aljaz Osterman Join Date: Dec 2010 Posts: 8 Rep Power: 15 Hi! When I'm trying to mesh a part of cylinder, made out of 3 blocks, I've found that when I try to have some grading in direction of symmetry axis, there's error message like: --> FOAM FATAL ERROR: face 451 area does not match neighbour 1051 by 11.4833% -- possible face ordering problem. ... etc. With simple grading (1) everything is ok (blockMesh and checkMesh). Interestingly though the mesh is generated and can be graded in all directions without a problem if central block is omitted (geometry of only 2 blocks - it's like a cylinder with a hole inside). The same holds true also if only the central block is meshed. Any suggestions how can I make graded mesh on all 3 blocks? Another question: what's the required precision when defining geometry (e.g. when using trigonometric functions) With best regards! P.S.: my blockMeshDict is pasted below, now it's not working, but if you replace '5' with '1' in simpleGrading specifications, it works. FoamFile { version 2.0; format ascii; class dictionary; object blockMeshDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // convertToMeters 1e-4; vertices ( (4.6194 150 -1.91342) (138.58193 150 -57.40251) (5 150 0) (150 150 0) (4.6194 150 1.91342) (138.58193 150 57.40251) (4.6194 200 -1.91342) (138.58193 200 -57.40251) (5 200 0) (150 200 0) (4.6194 200 1.91342) (138.58193 200 57.40251) (0 150 0) (0 200 0) ); blocks ( hex (0 2 3 1 6 8 9 7) (10 30 15) simpleGrading (1 10 5) hex (2 4 5 3 8 10 11 9) (10 30 15) simpleGrading (1 10 5) hex (12 4 2 0 13 10 8 6) (10 10 15) simpleGrading (1 1 5) ); edges ( arc 0 2 (4.903926 150 -0.975452) arc 2 4 (4.903926 150 0.975452) arc 1 3 (147.117792 150 -29.263548) arc 3 5 (147.117792 150 29.263548) arc 6 8 (4.903926 200 -0.975452) arc 8 10 (4.903926 200 0.975452) arc 7 9 (147.117792 200 -29.263548) arc 9 11 (147.117792 200 29.263548) ); patches ( patch inlet ( (6 8 9 7) (8 10 11 9) (6 13 10 8) ) patch outlet ( (0 2 3 1) (0 12 4 2) ) wall walls-A ( (2 4 5 3) ) wall walls-B ( (1 3 9 7) (3 5 11 9) // (0 2 8 6) // (2 4 10 8) ) cyclic bf ( (4 5 11 10) (12 4 10 13) (0 1 7 6) (12 0 6 13) ) ); mergePatchPairs ( );