[sergiopb91]

Hi everyone.

I'm trying to join a small cylinder with a venturi tube. When I made the venturi tube all faces were connected using " matching faces" but the face between venturi tube and the cylinder was not connected, and I don't know why.

So I would like to know which is the correct way to unit them. Here is my mesh:

convertToMeters 0.001;

vertices
(
(0 0 16) // 0
(0 16 0) // 1
(0 0 -16) // 2
(0 -16 0) // 3
(40 0 16) // 4
(40 16 0) // 5
(40 0 -16) // 6
(40 -16 0) // 7
(60.840712 0 8) // 8
(60.840712 8 0) // 9
(60.840712 0 -8) // 10
(60.840712 -8 0) // 11
(76.840712 0 8) // 12
(76.840712 8 0) // 13
(76.840712 0 -8) // 14
(76.840712 -8 0) // 15
(141.995484 0 16) // 16
(141.995484 16 0) // 17
(141.995484 0 -16) // 18
(141.995484 -16 0) // 19
(182 0 16) // 20
(182 16 0) // 21
(182 0 -16) // 22
(182 -16 0) // 23
(65.840712 8 0) // 24
(71.840712 8 0) // 25
(68.840712 7.416198487 3) // 26
(68.840712 7.416198487 -3) // 27
(65.840712 12 0) // 28
(71.840712 12 0) // 29
(68.840712 12 3) // 30
(68.840712 12 -3) // 31

);

blocks
(
hex (0 3 2 1 4 7 6 5) (60 40 40) simpleGrading (1 1 1)
hex (4 7 6 5 8 11 10 9) (60 40 40) simpleGrading (1 1 1)
hex (8 11 10 9 12 15 14 13) (60 40 40) simpleGrading (1 1 1)
hex (12 15 14 13 16 19 18 17) (60 40 40) simpleGrading (1 1 1)
hex (16 19 18 17 20 23 22 21) (60 40 40) simpleGrading (1 1 1)
hex (28 31 29 30 24 27 25 26) (60 40 40) simpleGrading (1 1 1)
);

edges
(
arc 0 1 (0 11.3137085 11.3137085)
arc 1 2 (0 11.3137085 -11.3137085)
arc 2 3 (0 -11.3137085 -11.3137085)
arc 3 0 (0 -11.3137085 11.3137085)
arc 4 5 (40 11.3137085 11.3137085)
arc 5 6 (40 11.3137085 -11.3137085)
arc 6 7 (40 -11.3137085 -11.3137085)
arc 7 4 (40 -11.3137085 11.3137085)
arc 8 9 (60.840712 5.656854 5.656854)
arc 9 10 (60.840712 5.656854 -5.656854)
arc 10 11 (60.840712 -5.656854 -5.656854)
arc 11 8 (60.840712 -5.656854 5.656854)
arc 12 13 (76.840712 5.656854 5.656854)
arc 13 14 (76.840712 5.656854 -5.656854)
arc 14 15 (76.840712 -5.656854 -5.656854)
arc 15 12 (76.840712 -5.656854 5.656854)
arc 16 17 (141.995484 11.3137085 11.3137085)
arc 17 18 (141.995484 11.3137085 -11.3137085)
arc 18 19 (141.995484 -11.3137085 -11.3137085)
arc 19 16 (141.995484 -11.3137085 11.3137085)
arc 20 21 (182 11.3137085 11.3137085)
arc 21 22 (182 11.3137085 -11.3137085)
arc 22 23 (182 -11.3137085 -11.3137085)
arc 23 20 (182 -11.3137085 11.3137085)
arc 24 26 (70.962032 8 2.121320)
arc 26 25 (70.962032 8 -2.121320)
arc 25 27 (66.719392 8 -2.121320)
arc 27 24 (66.719392 8 2.121320)
arc 28 30 (70.962032 12 2.121320)
arc 30 29 (70.962032 12 -2.121320)
arc 29 31 (66.719392 12 -2.121320)
arc 31 28 (66.719392 12 2.121320)
);

boundary
(
inlet
{
type patch;
faces
(
(0 3 2 1)


);
}
outlet
{
type patch;
faces
(
(20 23 22 21)


);
}
rightup
{
type wall;
faces
(
(0 1 5 4) (4 5 9 8) (12 13 17 16) (16 17 21 20) (8 9 13 12)

);
}
leftup
{
type wall;
faces
(
(1 2 6 5) (5 6 10 9) (13 14 18 17) (17 18 22 21) (9 10 14 13)

);
}
rightdown
{
type wall;
faces
(
(0 3 7 4) (4 7 11 8) (8 11 15 12) (12 15 19 16) (16 19 23 20)
);
}
leftdown
{
type wall;
faces
(
(2 3 7 6) (6 7 11 10) (10 11 15 14) (14 15 19 18) (18 19 23 22)

);
}
atmosfera
{
type patch;
faces
(
(30 29 31 28)

);
}
smallcylinder
{
type wall;
faces
(
(24 28 30 26) (26 30 29 25) (25 29 31 27) (27 31 28 24)
);
}
);

mergePatchPairs
(
);

I also read about mergePatchPairs to join two blocks but I don't have much experience with blockmesh so I don't know if I can connect the face (24 26 25 27) "output small cylinder" with the venturi tube because the entrance to the venturi tube is composed of two faces (8 9 13 12) and (9 10 14 13).

I would appreciate any help.

[sergiopb91]

Hi to all.

I could join the two cylinders but when run checkMesh got the following error:

Overall domain bounding box (0 -0.016 -0.016) (0.182 0.016 0.016)
Mesh has 3 geometric (non-empty/wedge) directions (1 1 1)
Mesh has 3 solution (non-empty) directions (1 1 1)
Boundary openness (6.47596e-17 -3.05627e-15 -5.28774e-15) OK.
Max cell openness = 3.75848e-16 OK.
Max aspect ratio = 320.738 OK.
Minimum face area = 4.86213e-12. Maximum face area = 1.39607e-06. Face area magnitudes OK.
Min volume = 2.85515e-14. Max volume = 7.9738e-10. Total volume = 0.000108115. Cell volumes OK.
Mesh non-orthogonality Max: 88.6173 average: 22.2726
*Number of severely non-orthogonal (> 70 degrees) faces: 19832.
Non-orthogonality check OK.
<<Writing 19832 non-orthogonal faces to set nonOrthoFaces
***Error in face pyramids: 12 faces are incorrectly oriented.
<<Writing 12 faces with incorrect orientation to set wrongOrientedFaces
***Max skewness = 4.97893, 2 highly skew faces detected which may impair the quality of the results
<<Writing 2 skew faces to set skewFaces
Coupled point location match (average 0) OK.

Failed 2 mesh checks.

End

I changed the order of vertices and blocks because was getting 3 errors more, but now I don't know where the error is. Here is my mesh:


vertices
(
(0 0 16) // 0
(0 -16 0) // 1
(0 0 -16) // 2
(0 16 0) // 3
(40 0 16) // 4
(40 -16 0) // 5
(40 0 -16) // 6
(40 16 0) // 7
(60.840712 0 8) // 8
(60.840712 -8 0) // 9
(60.840712 0 -8) // 10
(60.840712 8 0) // 11
(76.840712 0 8) // 12
(76.840712 -8 0) // 13
(76.840712 0 -8) // 14
(76.840712 8 0) // 15
(141.995484 0 16) // 16
(141.995484 -16 0) // 17
(141.995484 0 -16) // 18
(141.995484 16 0) // 19
(182 0 16) // 20
(182 -16 0) // 21
(182 0 -16) // 22
(182 16 0) // 23
(68.840712 16 3) // 24
(65.840712 16 0) // 25
(68.840712 16 -3) // 26
(71.840712 16 0) // 27
(68.840712 7.416198487 3) // 28
(65.840712 8 0) // 29
(68.840712 7.416198487 -3) // 30
(71.840712 8 0) // 31

);

blocks
(
hex (0 1 2 3 4 5 6 7) (60 40 40) simpleGrading (1 1 1)
hex (4 5 6 7 8 9 10 11) (60 40 40) simpleGrading (1 1 1)
hex (8 9 10 11 12 13 14 15) (60 40 40) simpleGrading (1 1 1)
hex (12 13 14 15 16 17 18 19) (60 40 40) simpleGrading (1 1 1)
hex (16 17 18 19 20 21 22 23) (60 40 40) simpleGrading (1 1 1)
hex (24 25 26 27 28 29 30 31) (60 40 40) simpleGrading (1 1 1)
);

edges
(
arc 0 1 (0 -11.3137085 11.3137085)
arc 1 2 (0 -11.3137085 -11.3137085)
arc 2 3 (0 11.3137085 11.3137085)
arc 3 0 (0 11.3137085 11.3137085)
arc 4 5 (40 -11.3137085 11.3137085)
arc 5 6 (40 -11.3137085 -11.3137085)
arc 6 7 (40 11.3137085 -11.3137085)
arc 7 4 (40 11.3137085 11.3137085)
arc 8 9 (60.840712 -5.656854 5.656854)
arc 9 10 (60.840712 -5.656854 -5.656854)
arc 10 11 (60.840712 5.656854 -5.656854)
arc 11 8 (60.840712 5.656854 5.656854)
arc 12 13 (76.840712 -5.656854 5.656854)
arc 13 14 (76.840712 -5.656854 -5.656854)
arc 14 15 (76.840712 5.656854 -5.656854)
arc 15 12 (76.840712 5.656854 5.656854)
arc 16 17 (141.995484 -11.3137085 11.3137085)
arc 17 18 (141.995484 -11.3137085 -11.3137085)
arc 18 19 (141.995484 11.3137085 -11.3137085)
arc 19 16 (141.995484 11.3137085 11.3137085)
arc 20 21 (182 -11.3137085 11.3137085)
arc 21 22 (182 -11.3137085 -11.3137085)
arc 22 23 (182 11.3137085 -11.3137085)
arc 23 20 (182 11.3137085 11.3137085)
arc 24 25 (66.719392 16 2.121320)
arc 25 26 (66.719392 16 -2.121320)
arc 26 27 (70.962032 16 -2.121320)
arc 27 24 (70.962032 16 2.121320)
arc 28 29 (66.719392 8 2.121320)
arc 29 30 (66.719392 8 -2.121320)
arc 30 31 (70.962032 8 -2.121320)
arc 31 28 (70.962032 8 2.121320)
);

boundary
(
inlet
{
type patch;
faces
(
(0 1 2 3)


);
}
outlet
{
type patch;
faces
(
(20 21 22 23)


);
}
rightup
{
type wall;
faces
(
(0 3 7 4) (4 7 11 8) (12 15 19 16) (16 19 23 20)

);
}
leftup
{
type wall;
faces
(
(3 2 6 7) (7 6 10 11) (15 14 18 19) (19 18 22 23)

);
}
rightdown
{
type wall;
faces
(
(1 0 4 5) (5 4 8 9) (9 8 12 13) (13 12 16 17) (17 16 20 21)
);
}
leftdown
{
type wall;
faces
(
(2 1 5 6) (6 5 9 10) (10 9 13 14) (14 13 17 18) (18 17 21 22)

);
}
atmosfera
{
type patch;
faces
(
(24 25 26 27)

);
}
smallcylinder
{
type wall;
faces
(
(25 24 28 29) (26 25 29 30) (26 27 31 30) (27 24 28 31)
);
}

masterPatch
{
type patch;
faces
(
(28 29 30 31)
);
}

slavePatch
{
type wall;
faces
(
(8 11 15 12) (11 10 14 15)
);
}



);
mergePatchPairs
(
(masterPatch slavePatch)

);

Can someone help me? Please.