| ihu945 |
June 8, 2016 04:32 |
Weird velocity from flow around circular cylinder
3 Attachment(s)
Hello, foamers.
I am trying to do a simulation Flow around a circular cylinder near a plane wall.
However, because of weirdly high courant number by too high velocity, I cannot do simulation.
Code:
convertToMeters 1;
vertices
(
(-10 -1.5 0)
( 10 -1.5 0)
(30 -1.5 0)
(-1.0607 -1.0607 0)
(1.0607 -1.0607 0)
(-0.3536 -0.3536 0)
( 0.3536 -0.3536 0)
(-0.3536 0.3536 0)
( 0.3536 0.3536 0)
(-1.0607 1.0607 0)
(1.0607 1.0607 0)
(-10 15 0)
( 10 15 0)
(30 15 0)
(-10 -1.5 1)
( 10 -1.5 1)
(30 -1.5 1)
(-1.0607 -1.0607 1)
(1.0607 -1.0607 1)
(-0.3536 -0.3536 1)
( 0.3536 -0.3536 1)
(-0.3536 0.3536 1)
( 0.3536 0.3536 1)
(-1.0607 1.0607 1)
(1.0607 1.0607 1)
(-10 15 1)
( 10 15 1)
(30 15 1)
);
blocks
(
hex (0 3 9 11 14 17 23 25) (10 10 1) simpleGrading (1 1 1)
hex (1 4 3 0 15 18 17 14) (10 10 1) simpleGrading (1 1 1)
hex (4 1 12 10 18 15 26 24) (10 10 1) simpleGrading (1 1 1)
hex (10 12 11 9 24 26 25 23) (10 10 1) simpleGrading (1 1 1)
hex (3 5 7 9 17 19 21 23) (10 10 1) simpleGrading (1 1 1)
hex (4 6 5 3 18 20 19 17) (10 10 1) simpleGrading (1 1 1)
hex (6 4 10 8 20 18 24 22) (10 10 1) simpleGrading (1 1 1)
hex (8 10 9 7 22 24 23 21) (10 10 1) simpleGrading (1 1 1)
hex (1 2 13 12 15 16 27 26) (10 10 1) simpleGrading (1 1 1)
);
edges
(
arc 5 7 (-0.5 0 0)
arc 19 21 (-0.5 0 1)
arc 6 8 (0.5 0 0)
arc 20 22 (0.5 0 1)
arc 7 8 (0 0.5 0)
arc 21 22 (0 0.5 1)
arc 5 6 (0 -0.5 0)
arc 19 20(0 -0.5 1)
arc 3 9 (-1.5 0 0)
arc 17 23 (-1.5 0 1)
arc 4 10 (1.5 0 0)
arc 18 24 (1.5 0 1)
arc 9 10 (0 1.5 0)
arc 23 24 (0 1.5 1)
arc 3 4 (0 -1.5 0)
arc 17 18 (0 -1.5 1)
);
boundary
(
inlet
{
type wall;
faces
(
(25 11 0 14)
);
}
outlet
{
type wall;
faces
(
(13 27 16 2)
);
}
top
{
type wall;
faces
(
(12 11 25 26)
(13 12 26 27)
);
}
bottom
{
type wall;
faces
(
(0 1 14 15)
(1 2 15 16)
);
}
cylinder
{
type wall;
faces
(
(7 8 21 22)
(22 8 6 20)
(6 5 19 20)
(5 7 21 19)
);
}
sides
{
type empty;
faces
(
(11 12 10 9)
(0 11 9 3)
(0 3 4 1)
(4 10 12 1)
(9 10 8 7)
(3 9 7 5)
(3 5 6 4)
(6 8 10 4)
(12 13 2 1)
(25 23 24 26)
(14 17 23 25)
(14 15 18 17)
(18 15 26 24)
(23 21 22 24)
(17 19 21 23)
(17 18 20 19)
(20 18 24 22)
(26 15 16 27)
);
}
);
mergePatchPairs
(
);
Code:
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
inlet
{
type fixedValue;
value uniform (1 0 0);
}
outlet
{
type zeroGradient;
}
top
{
type zeroGradient;
}
bottom
{
type fixedValue;
value uniform (0 0 0);
}
cylinder
{
type fixedValue;
value uniform (0 0 0);
}
sides
{
type empty;
}
}
These are my blockMeshDict and initial condition for velocity.
And pictures below are from paraview.
when t = 0,
Attachment 48042
When t = 0.003
Attachment 48043
And bottom part of second picture,
Attachment 48044
Like this, velocity of bottom becomes very high, and I have no idea that it is right or something is wrong.
Please, help me.
Thank you |
