1. Dynamic Mesh
in OpenFOAM
Fumiya Nozaki
Last updated: 31 December 2015
114 PAGES
1

2. Disclaimer
“This offering is not approved or
endorsed by OpenCFD Limited,
the producer of the OpenFOAM
software and owner of the
OPENFOAM® and OpenCFD®
trade marks.”
2

3. Dynamic Mesh in OpenFOAM
In OpenFOAM, the mesh motions and the topology
changes are handled by Dynamic Mesh functionality.
Settings for Dynamic Mesh are described in
dynamicMeshDict file located in the constant directory.
Solvers that can handle these mesh changes have the
letters “DyM”, an abbreviation for Dynamic Mesh, in its
name.
e.g. pimpleDyMFoam, interDyMFoam
3

4. Dynamic Mesh in OpenFOAM
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dynamicFvMesh solidBodyMotionFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
solidBodyMotionFvMeshCoeffs
{
cellZone rotor;
solidBodyMotionFunction rotatingMotion;
rotatingMotionCoeffs
{
origin (0 0 0);
axis (0 0 1);
omega 6.2832; // rad/s
}
}
// ************************************************************************* //
constant/dynamicMeshDict
Selection of dynamicFvMesh
type from available options
Settings for the selected
dynamicFvMesh
4

5. Dynamic Mesh in OpenFOAM
In OpenFOAM, the mesh motions and the topology
changes are handled by Dynamic Mesh functionality.
Settings for Dynamic Mesh are described in
dynamicMeshDict file located in the constant directory.
Solvers that can handle these mesh changes have the
letters “DyM”, an abbreviation for Dynamic Mesh, in its
name.
e.g. pimpleDyMFoam, interDyMFoam
5

6. while (runTime.run())
{
#include "readControls.H"
#include "CourantNo.H"
#include "setDeltaT.H"
runTime++;
Info<< "Time = " << runTime.timeName() << nl << endl;
mesh.update();
// Calculate absolute flux from the mapped surface velocity
phi = mesh.Sf() & Uf;
if (mesh.changing() && correctPhi)
{
#include "correctPhi.H"
}
// Make the flux relative to the mesh motion
fvc::makeRelative(phi, U);
if (mesh.changing() && checkMeshCourantNo)
{
#include "meshCourantNo.H"
}
applications/solvers/incompressible/pimpleFoam/pimpleDyMFoam/pimpleDyMFoam.C
It calls the mesh motion library
to calculate the new position of
points and update the mesh.
Dynamic Mesh in OpenFOAM 6

7. Available types of dynamicFvMesh without topological changes
• staticFvMesh
Disable dynamic mesh
• solidBodyMotionFvMesh
Perform the rigid-body motions such as translational and rotational
movements
• multiSolidBodyMotionFvMesh
Perform the rigid-body motions in multiple regions
• dynamicMotionSolverFvMesh
Solve a Laplace’s equation for the motion displacement or motion
velocity to calculate the updated position of points
• dynamicInkJetFvMesh
Move mesh points sinusoidally in the x direction by explicitly calculating
the new positions
• dynamicRefineFvMesh
Refine the mesh depending on the user specified field values
7

8. Available types of dynamicFvMesh with topological changes
• rawTopoChangerFvMesh
• movingConeTopoFvMesh
• mixerFvMesh
• linearValveFvMesh
• linearValveLayersFvMesh
Under survey
8

9. Inheritance diagram for dynamicFvMesh models
dynamicFvMesh
staticFvMesh
dynamicInkJetFvMeshsolidBodyMotionFvMesh
multiSolidBodyMotionFvMesh
dynamicMotionSolverFvMesh
dynamicRefineFvMesh
Abstract base class for geometry
and/or topology changing fvMesh
9

10. Inheritance diagram for dynamicFvMesh models
dynamicFvMesh
rawTopoChangerFvMesh
movingConeTopoFvMesh
mixerFvMesh
linearValveFvMesh
linearValveLayersFvMesh
topoChangerFvMesh Abstract base class for
a topology changing fvMesh
10

11. solidBodyMotionFvMesh

12. Available types of solid motions
 Translational motions
• linearMotion : Uniform linear motion with constant velocity
• oscillatingLinearMotion : Oscillating linear motion
 Rotational motions
• rotatingMotion : Uniform circular motion
• axisRotationMotion : Uniform circular motion
• oscillatingRotatingMotion : Oscillating rotation motion
 Ship Design Analysis [1]
• SDA
 Tabulated data
• tabulated6DoFMotion
 Combination of above types
• multiMotion
12

13. linearMotion
dynamicFvMesh solidBodyMotionFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
solidBodyMotionFvMeshCoeffs
{
solidBodyMotionFunction linearMotion;
linearMotionCoeffs
{
velocity (1 0 0);
}
}
constant/dynamicMeshDict
13

14. oscillatingLinearMotion
dynamicFvMesh solidBodyMotionFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
solidBodyMotionFvMeshCoeffs
{
cellZone inletChannel;
solidBodyMotionFunction oscillatingLinearMotion;
oscillatingLinearMotionCoeffs
{
amplitude (0 0.5 0);
omega 3.14;
}
}
tutorials/incompressible/pimpleDyMFoam/oscillatingInletACMI2D/constant/
dynamicMeshDict
14

15. rotatingMotion
dynamicFvMesh solidBodyMotionFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
solidBodyMotionFvMeshCoeffs
{
cellZone rotor;
solidBodyMotionFunction rotatingMotion;
rotatingMotionCoeffs
{
origin (0 0 0);
axis (0 0 1);
omega 6.2832;
}
}
tutorials/incompressible/pimpleDyMFoam/mixerVesselAMI2D/constant/dynamicMeshDict
15

16. axisRotationMotion
dynamicFvMesh solidBodyMotionFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
solidBodyMotionFvMeshCoeffs
{
cellZone rotor;
solidBodyMotionFunction axisRotationMotion;
axisRotationMotionCoeffs
{
origin (0 0 0);
radialVelocity (0 0 360);
}
}
tutorials/incompressible/pimpleDyMFoam/mixerVesselAMI2D/constant/dynamicMeshDict
16

17. oscillatingRotatingMotion
dynamicFvMesh solidBodyMotionFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
solidBodyMotionFvMeshCoeffs
{
cellZone rotor;
solidBodyMotionFunction oscillatingRotatingMotion;
oscillatingRotatingMotionCoeffs
{
origin (0 0 0);
omega 6.28;
amplitude (0 0 45);
}
}
tutorials/incompressible/pimpleDyMFoam/mixerVesselAMI2D/constant/dynamicMeshDict
17

18. oscillatingRotatingMotion
rotor
18

19. oscillatingRotatingMotion
rotor
19

20. oscillatingRotatingMotion
rotor
20

21. oscillatingRotatingMotion
rotor
21

22. oscillatingRotatingMotion
rotor
22

23. oscillatingRotatingMotion
rotor
23

24. oscillatingRotatingMotion
rotor
24

25. oscillatingRotatingMotion
rotor
25

26. oscillatingRotatingMotion
rotor
26

27. oscillatingRotatingMotion
rotor
27

28. oscillatingRotatingMotion
rotor
28

29. oscillatingRotatingMotion
rotor
29

30. oscillatingRotatingMotion
rotor
30

31. oscillatingRotatingMotion
rotor
31

32. oscillatingRotatingMotion
rotor
32

33. oscillatingRotatingMotion
rotor
33

34. oscillatingRotatingMotion
rotor
34

35. oscillatingRotatingMotion
rotor
35

36. oscillatingRotatingMotion
rotor
36

37. oscillatingRotatingMotion
rotor
37

38. oscillatingRotatingMotion
rotor
38

39. tabulated6DoFMotion
dynamicFvMesh solidBodyMotionFvMesh;
solidBodyMotionFvMeshCoeffs
{
solidBodyMotionFunction tabulated6DoFMotion;
tabulated6DoFMotionCoeffs
{
CofG (0 0 0);
timeDataFileName "$FOAM_CASE/constant/6DoF.dat";
}
}
tutorials/multiphase/interDyMFoam/ras/sloshingTank3D6DoF/constant/dynamicMeshDict
39

40. 100
(
(0 ((0 0 0) (0 0 0)))
(0.40404 ((0.401298 0.952899 0.321827) (4.82741 2.79073 2.00649)))
(0.808081 ((0.786273 1.8071 0.635266) (9.52899 5.3597 3.93137)))
(1.21212 ((1.13927 2.47414 0.932149) (13.9822 7.5028 5.69634)))
(1.61616 ((1.44593 2.88493 1.20474) (18.071 9.04972 7.22963)))
(2.0202 ((1.69377 2.99691 1.44593) (21.6889 9.87755 8.46886)))
(2.42424 ((1.87273 2.7985 1.64943) (24.7414 9.92051 9.36363)))
(2.82828 ((1.97551 2.31024 1.80994) (27.1492 9.17518 9.87755)))
. . .
(40 ((1.82589 1.65428 -0.575807) (-8.6371 2.70906 9.12945)))
)
tutorials/multiphase/interDyMFoam/ras/sloshingTank3D6DoF/constant/6DoF.dat
tabulated6DoFMotion 40

41. multiMotion
dynamicFvMesh solidBodyMotionFvMesh;
solidBodyMotionFvMeshCoeffs
{
solidBodyMotionFunction multiMotion;
multiMotionCoeffs
{
// Table rotating in z axis
rotatingTable
{
solidBodyMotionFunction rotatingMotion;
rotatingMotionCoeffs
{
origin (0 0.1 0);
axis (0 0 1);
omega 6.2832; // rad/s
}
}
// Tube rocking on rotating table
rotatingBox
{
solidBodyMotionFunction oscillatingRotatingMotion;
oscillatingRotatingMotionCoeffs
{
origin (0 0 0);
omega 40;
amplitude (45 0 0);
}
}
}
}
tutorials/multiphase/interDyMFoam/ras/testTubeMixer/constant/dynamicMeshDict
// Table rotating in z axis
rotatingTable
{
solidBodyMotionFunction rotatingMotion;
rotatingMotionCoeffs
{
origin (0 0.1 0);
axis (0 0 1);
omega 6.2832;
}
}
// Tube rocking on rotating table
rotatingBox
{
solidBodyMotionFunction oscillatingRotatingMotion;
oscillatingRotatingMotionCoeffs
{
origin (0 0 0);
omega 40;
amplitude (45 0 0);
}
}
41

42. multiSolidBodyMotionFvMesh

43. dynamicMeshDict
dynamicFvMesh multiSolidBodyMotionFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
multiSolidBodyMotionFvMeshCoeffs
{
rotor1
{
solidBodyMotionFunction rotatingMotion;
rotatingMotionCoeffs
{
origin (0 0 0);
axis (0 0 1);
omega 3.1416;
}
}
rotor2
{
solidBodyMotionFunction rotatingMotion;
rotatingMotionCoeffs
{
origin (4 0 0);
axis (0 0 1);
omega -3.1416;
}
}
}
// ************************************************************************* //
constant/dynamicMeshDict
Different settings of rigid body
motions in multiple cellZones
43

44. An example usage
rotor2
rotor1
44

45. dynamicMotionSolverFvMesh

46. Brief description of dynamicMotionSolverFvMesh
 Solve a Laplace’s equation for the motion displacement 𝑑 𝑚 [𝑚] or motion
velocity 𝑢 𝑚 [ 𝑚 𝑠]:
𝛻 ∙ 𝛾𝛻𝑑 𝑚 = 0
or
𝛻 ∙ 𝛾𝛻𝑢 𝑚 = 0
 Users can select which equations to be solved.
 Users need to specify how to calculate the diffusion coefficient 𝛾 of the
equation.
46

47. dynamicMeshDict
dynamicFvMesh dynamicMotionSolverFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
solver velocityComponentLaplacian;
velocityComponentLaplacianCoeffs
{
component x;
diffusivity directional (1 200 0);
}
tutorials/incompressible/pimpleDyMFoam/movingCone/constant/dynamicMeshDict
 Users can select which equations to be solved by choosing the solver
from the available options.
 Users need to specify how to calculate the diffusion coefficient 𝛾 of
the equation by selecting from the options.
1
2
1
2
47

48. Available types of solver
 Solving for cellDisplacement (unit: [𝑚])
• displacementLaplacian
• displacementComponentLaplacian
• displacementInterpolation
• displacementLayeredMotion
• displacementSBRStress
 Solving for cellMotionU (unit: [ 𝑚 𝑠])
• velocityLaplacian
• velocityComponentLaplacian
48

49. Available types of solver | displacementLaplacian
void Foam::displacementLaplacianFvMotionSolver::solve()
{
// The points have moved so before interpolation update
// the motionSolver accordingly
movePoints(fvMesh_.points());
diffusivity().correct();
pointDisplacement_.boundaryField().updateCoeffs();
Foam::solve
(
fvm::laplacian
(
diffusivity().operator()(),
cellDisplacement_,
"laplacian(diffusivity,cellDisplacement)"
)
);
}
src/fvMotionSolver/fvMotionSolvers/displacement/laplacian/
displacementLaplacianFvMotionSolver.C
Solving Laplace’s Eqn.
49

50. Available types of solver | velocityLaplacian
void Foam::velocityLaplacianFvMotionSolver::solve()
{
// The points have moved so before interpolation update
// the fvMotionSolver accordingly
movePoints(fvMesh_.points());
diffusivityPtr_->correct();
pointMotionU_.boundaryField().updateCoeffs();
Foam::solve
(
fvm::laplacian
(
diffusivityPtr_->operator()(),
cellMotionU_,
"laplacian(diffusivity,cellMotionU)"
)
);
}
src/fvMotionSolver/fvMotionSolvers/velocity/laplacian/
velocityLaplacianFvMotionSolver.C
Solving Laplace’s Eqn.
50

51. Available types of diffusivity models
• uniform
• directional
• motionDirectional
• inverseVolume
• inverseDistance
• inverseFaceDistance
• inversePointDistance
• quadratic
• exponential
• file
51

52. Class diagram of diffusivity models
motionDiffusivity
uniformDiffusivity quadraticDiffusivity exponentialDiffusivity fileDiffusivity
directionalDiffusivity
motionDirectionalDiffusivity
inverseVolumeDiffusivity
inverseDistanceDiffusivity
inverseFaceDistanceDiffusivity
inversePointDistanceDiffusivity
 Source Code: src/fvMotionSolver/motionDiffusivity/
52

53. Class diagram of diffusivity models
motionDiffusivity class
//- Return diffusivity field
virtual tmp<surfaceScalarField> operator()() const = 0;
// Protected data
surfaceScalarField faceDiffusivity_;
correct()
//- Correct the motion diffusivity
virtual void correct() = 0;
uniformDiffusivity class
virtual tmp<surfaceScalarField> operator()() const
{
return faceDiffusivity_;
}
directionalDiffusivity class
motionDirectionalDiffusivity class
inverseVolumeDiffusivity class
inverseDistanceDiffusivity class
inverseFaceDistanceDiffusivity class
inversePointDistanceDiffusivity class
override
override
53

54. Class diagram of diffusivity models
motionDiffusivity class
//- Return diffusivity field
virtual tmp<surfaceScalarField> operator()() const = 0;
Foam::tmp<Foam::surfaceScalarField>
Foam::quadraticDiffusivity::operator()() const
{
return sqr(basicDiffusivityPtr_->operator()());
}
//- Correct the motion diffusivity
virtual void correct() = 0;
quadraticDiffusivity class
override
void Foam::quadraticDiffusivity::correct()
{
basicDiffusivityPtr_->correct();
}
54

55. Class diagram of diffusivity models
motionDiffusivity class
//- Return diffusivity field
virtual tmp<surfaceScalarField> operator()() const = 0;
Foam::tmp<Foam::surfaceScalarField>
Foam::exponentialDiffusivity::operator()() const
{
return exp(-alpha_/basicDiffusivityPtr_->operator()());
}
//- Correct the motion diffusivity
virtual void correct() = 0;
exponentialDiffusivity class
override
void Foam::exponentialDiffusivity::correct()
{
basicDiffusivityPtr_->correct();
}
55

56. Calculation of diffusion coefficient
void Foam::inverseVolumeDiffusivity::correct()
{
volScalarField V
(
IOobject
(
"V",
mesh().time().timeName(),
mesh(),
IOobject::NO_READ,
IOobject::NO_WRITE,
false
),
mesh(),
dimless,
zeroGradientFvPatchScalarField::typeName
);
V.internalField() = mesh().V();
V.correctBoundaryConditions();
faceDiffusivity_ = 1.0/fvc::interpolate(V);
}
src/fvMotionSolver/motionDiffusivity/inverseVolume/inverseVolumeDiffusivity.C
In the case of inverseVolume type,
faceDiffusivity_ is calculated as the
inverse of the cell volumes as its
name indicates.
 correct() function calculates the diffusion coefficient field faceDiffusivity_
56

57. • cmptMultiply(a, b) where 𝑎 = 𝑎0, 𝑎1, 𝑎2 , 𝑏 = 𝑏0, 𝑏1, 𝑏2
𝑐𝑚𝑝𝑡𝑀𝑢𝑙𝑡𝑖𝑝𝑙𝑦 𝑎, 𝑏 = 𝑎0 𝑏0, 𝑎1 𝑏1, 𝑎2 𝑏2
Calculation of diffusion coefficient
void Foam::directionalDiffusivity::correct()
{
const surfaceVectorField n(mesh().Sf()/mesh().magSf());
faceDiffusivity_ == (n & cmptMultiply(diffusivityVector_, n));
}
src/fvMotionSolver/motionDiffusivity/directional/directionalDiffusivity.C
In the case of directional type,
faceDiffusivity_ is calculated using
the user specified diffusivityVector_
and unit normal vectors of each face.
57

58. Mesh update process
bool Foam::dynamicMotionSolverFvMesh::update()
{
fvMesh::movePoints(motionPtr_->newPoints());
if (foundObject<volVectorField>("U"))
{
volVectorField& U =
const_cast<volVectorField&>(lookupObject<volVectorField>("U"));
U.correctBoundaryConditions();
}
return true;
}
src/dynamicFvMesh/dynamicMotionSolverFvMesh/dynamicMotionSolverFvMesh.C
Foam::tmp<Foam::pointField> Foam::motionSolver::newPoints()
{
solve();
return curPoints();
}
src/dynamicMesh/motionSolver/motionSolver/motionSolver.C
 mesh.update() calls update() function of dynamicMotionSolverFvMesh class.
58

59. void Foam::velocityComponentLaplacianFvMotionSolver::solve()
{
// The points have moved so before interpolation update
// the fvMotionSolver accordingly
movePoints(fvMesh_.points());
diffusivityPtr_->correct();
pointMotionU_.boundaryField().updateCoeffs();
Foam::solve
(
fvm::laplacian
(
diffusivityPtr_->operator()(),
cellMotionU_,
"laplacian(diffusivity,cellMotionU)"
)
);
}
src/fvMotionSolver/fvMotionSolvers/componentVelocity/componentLaplacian/
velocityComponentLaplacianFvMotionSolver.C
Foam::tmp<Foam::pointField> Foam::motionSolver::newPoints()
{
solve();
return curPoints();
}
src/dynamicMesh/motionSolver/motionSolver/motionSolver.C
Solve Laplace’s Eqn.
Update the diffusion
coefficient field
Mesh update process 59

60. Foam::tmp<Foam::pointField> Foam::motionSolver::newPoints()
{
solve();
return curPoints();
}
src/dynamicMesh/motionSolver/motionSolver/motionSolver.C
Foam::tmp<Foam::pointField>
Foam::velocityComponentLaplacianFvMotionSolver::curPoints() const
{
volPointInterpolation::New(fvMesh_).interpolate
(
cellMotionU_,
pointMotionU_
);
tmp<pointField> tcurPoints(new pointField(fvMesh_.points()));
tcurPoints().replace
(
cmpt_,
tcurPoints().component(cmpt_)
+ fvMesh_.time().deltaTValue()*pointMotionU_.internalField()
);
twoDCorrectPoints(tcurPoints());
return tcurPoints;
}
src/fvMotionSolver/fvMotionSolvers/componentVelocity/componentLaplacian/
velocityComponentLaplacianFvMotionSolver.C
Calculate the new
position of points
Interpolate the motion velocity
from cell centres to points
Mesh update process 60

61. movingWall
{
type uniformFixedValue;
uniformValue constant 1;
}
Moving at constant
velocity of 1m/s
“farField.*”
{
type slip;
}
movingCone tutorial 61

62. movingCone tutorial 62

63. movingCone tutorial 63

64. movingCone tutorial 64

65. movingCone tutorial 65

66. movingCone tutorial 66

67. movingCone tutorial 67

68. movingCone tutorial 68

69. movingCone tutorial 69

70. movingCone tutorial 70

71. movingCone tutorial 71

72. movingCone tutorial 72

73. movingCone tutorial 73

74. movingCone tutorial 74

75. movingCone tutorial 75

76. movingCone tutorial 76

77. dynamicInkJetFvMesh

78. Brief description of dynamicInkJetFvMesh
 From the description in the header file
 Mesh motion specifically for the "pumping" system of an ink-jet injector.

The set of points in the "pumping" region are compressed and expanded
sinusoidally to impose a sinusoidal variation of the flow at the nozzle exit.
Points can move only in the X direction
78

79. Brief description of dynamicInkJetFvMesh
Points can move only in the X direction
 From the description in the header file
 Mesh motion specifically for the "pumping" system of an ink-jet injector.

The set of points in the "pumping" region are compressed and expanded
sinusoidally to impose a sinusoidal variation of the flow at the nozzle exit.
79

80. An example usage
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dynamicFvMesh dynamicInkJetFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
dynamicInkJetFvMeshCoeffs
{
amplitude 0.5;
frequency 1;
refPlaneX 0.0;
}
// ************************************************************************* //
constant/dynamicMeshDict
Three input parameters
control the mesh motions
80

81. An example usage
refPlaneX
-1.0 -0.5 0.0 0.5 1.0
81

82. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
82

83. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
83

84. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
84

85. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
85

86. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
86

87. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
87

88. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
88

89. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
89

90. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
90

91. An example usage
-1.0 -0.5 0.0 0.5 1.0
refPlaneX
91

92. Calculation of the new position of points
bool Foam::dynamicInkJetFvMesh::update()
{
scalar scalingFunction =
0.5*
(
::cos(constant::mathematical::twoPi*frequency_*time().value())
- 1.0
);
Info<< "Mesh scaling. Time = " << time().value() << " scaling: "
<< scalingFunction << endl;
pointField newPoints = stationaryPoints_;
newPoints.replace
(
vector::X,
stationaryPoints_.component(vector::X)*
(
1.0
+ pos
(
- (stationaryPoints_.component(vector::X))
- refPlaneX_
)*amplitude_*scalingFunction
)
);
src/dynamicFvMesh/dynamicInkJetFvMesh/dynamicInkJetFvMesh.C
Explicitly calculate
the new position of points
Modify only the x-coordinate
92

93. Calculation of the new position of points
fvMesh::movePoints(newPoints);
volVectorField& U =
const_cast<volVectorField&>(lookupObject<volVectorField>("U"));
U.correctBoundaryConditions();
return true;
}
src/dynamicFvMesh/dynamicInkJetFvMesh/dynamicInkJetFvMesh.C
93

94. dynamicRefineFvMesh
Under survey

95. movingConeTopoFvMesh

96. Brief description of movingConeTopoFvMesh
 From the description in the header file
 Sample topoChangerFvMesh that moves an object in x direction
 and introduces/removes layers.
 It is designed exclusively for use with the movingCone tutorial.
96

97. An example usage
dynamicFvMesh movingConeTopoFvMesh;
motionSolverLibs ( "libfvMotionSolvers.so" );
movingConeTopoFvMeshCoeffs
{
motionVelAmplitude (1.5 0.0 0.0);
motionVelPeriod 0.003;
leftEdge 0.0;
leftObstacleEdge 0.0;
rightObstacleEdge 0.0;
right
{
minThickness 3e-5;
maxThickness 6e-5;
}
left
{
minThickness 3e-5;
maxThickness 5e-5;
}
}
constant/dynamicMeshDict
These parameters are required
but not used.
97

98.  Read dynamicMeshDict and set the values of private data
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
// Construct from components
Foam::movingConeTopoFvMesh::movingConeTopoFvMesh(const IOobject& io)
:
topoChangerFvMesh(io),
motionDict_
(
IOdictionary
(
IOobject
(
"dynamicMeshDict",
time().constant(),
*this,
IOobject::MUST_READ_IF_MODIFIED,
IOobject::NO_WRITE,
false
)
).subDict(typeName + "Coeffs")
),
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
Constructors 98

99. motionVelAmplitude_(motionDict_.lookup("motionVelAmplitude")),
motionVelPeriod_(readScalar(motionDict_.lookup("motionVelPeriod"))),
curMotionVel_
(
motionVelAmplitude_*
Foam::sin(time().value()*M_PI/motionVelPeriod_)
),
leftEdge_(readScalar(motionDict_.lookup("leftEdge"))),
curLeft_(readScalar(motionDict_.lookup("leftObstacleEdge"))),
curRight_(readScalar(motionDict_.lookup("rightObstacleEdge")))
{
Pout<< "Initial time:" << time().value()
<< " Initial curMotionVel_:" << curMotionVel_
<< endl;
addZonesAndModifiers();
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
Constructors (cont’d)
Read the parameters
from dynamicMeshDict
• motionVelAmplitude
• motionVelPeriod
• leftEdge
• leftObstacleEdge
• rightObstacleEdge
Create two faceZones
• rightExtrusionFaces
• leftExtrusionFaces
and modifiers for motion action
99

100. curLeft_ = average
(
faceZones()
[
faceZones().findZoneID("leftExtrusionFaces")
]().localPoints()
).x() - SMALL;
curRight_ = average
(
faceZones()
[
faceZones().findZoneID("rightExtrusionFaces")
]().localPoints()
).x() + SMALL;
motionMask_ = vertexMarkup
(
points(),
curLeft_,
curRight_
);
}
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
Constructors (cont’d) 100
The initial x-coordinates of left and
right sides of the moving obstacle
(curLeft_ and curRight_) are calculated
using the faceZones.

101. addZonesAndModifiers
void Foam::movingConeTopoFvMesh::addZonesAndModifiers()
{
// Add zones and modifiers for motion action
if
(
pointZones().size()
|| faceZones().size()
|| cellZones().size()
|| topoChanger_.size()
)
{
Info<< "void movingConeTopoFvMesh::addZonesAndModifiers() : "
<< "Zones and modifiers already present. Skipping."
<< endl;
return;
}
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
101
 Create two faceZones and modifiers for motion action

102. addZonesAndModifiers
Info<< "Time = " << time().timeName() << endl
<< "Adding zones and modifiers to the mesh" << endl;
const vectorField& fc = faceCentres();
const vectorField& fa = faceAreas();
labelList zone1(fc.size());
boolList flipZone1(fc.size(), false);
label nZoneFaces1 = 0;
labelList zone2(fc.size());
boolList flipZone2(fc.size(), false);
label nZoneFaces2 = 0;
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
102

103. addZonesAndModifiers
forAll(fc, faceI)
{
if
(
fc[faceI].x() > -0.003501
&& fc[faceI].x() < -0.003499
)
{
if ((fa[faceI] & vector(1, 0, 0)) < 0)
{
flipZone1[nZoneFaces1] = true;
}
zone1[nZoneFaces1] = faceI;
Info<< "face " << faceI << " for zone 1. Flip: "
<< flipZone1[nZoneFaces1] << endl;
nZoneFaces1++;
}
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
103
The faces whose center x-coordinates are
greater than -0.003501 and less than -0.003499
are added to the labelList zone1.
These hard-coded values are designed for movingCone tutorial.
For
movingCone
tutorial

104. addZonesAndModifiers
else if
(
fc[faceI].x() > -0.00701
&& fc[faceI].x() < -0.00699
)
{
if ((fa[faceI] & vector(1, 0, 0)) > 0)
{
flipZone2[nZoneFaces2] = true;
}
zone2[nZoneFaces2] = faceI;
Info<< "face " << faceI << " for zone 2. Flip: "
<< flipZone2[nZoneFaces2] << endl;
nZoneFaces2++;
}
}
zone1.setSize(nZoneFaces1);
flipZone1.setSize(nZoneFaces1);
zone2.setSize(nZoneFaces2);
flipZone2.setSize(nZoneFaces2);
Info<< "zone: " << zone1 << endl;
Info<< "zone: " << zone2 << endl;
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
104
The faces whose center x-coordinates are
greater than -0.00701 and less than -0.00699
are added to the labelList zone2.
Reset the size of four lists.
For
movingCone
tutorial

105. addZonesAndModifiers
List<pointZone*> pz(0);
List<faceZone*> fz(2);
List<cellZone*> cz(0);
label nFz = 0;
fz[nFz] =
new faceZone
(
"rightExtrusionFaces",
zone1,
flipZone1,
nFz,
faceZones()
);
nFz++;
fz[nFz] =
new faceZone
(
"leftExtrusionFaces",
zone2,
flipZone2,
nFz,
faceZones()
);
nFz++;
fz.setSize(nFz);
Info<< "Adding mesh zones." << endl;
addZones(pz, fz, cz);
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
105
Create two faceZones
• rightExtrusionFaces
from zone1 and flipZone1
• leftExtrusionFaces
from zone2 and flipZone2

106. addZonesAndModifiers
// Add layer addition/removal interfaces
List<polyMeshModifier*> tm(2);
label nMods = 0;
tm[nMods] =
new layerAdditionRemoval
(
"right",
nMods,
topoChanger_,
"rightExtrusionFaces",
readScalar
(
motionDict_.subDict("right").lookup("minThickness")
),
readScalar
(
motionDict_.subDict("right").lookup("maxThickness")
)
);
nMods++;
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
106

107. addZonesAndModifiers
tm[nMods] = new layerAdditionRemoval
(
"left",
nMods,
topoChanger_,
"leftExtrusionFaces",
readScalar
(
motionDict_.subDict("left").lookup("minThickness")
),
readScalar
(
motionDict_.subDict("left").lookup("maxThickness")
)
);
nMods++;
tm.setSize(nMods);
Info<< "Adding " << nMods << " mesh modifiers" << endl;
topoChanger_.addTopologyModifiers(tm);
write();
}
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
107

108. vertexMarkup
Foam::tmp<Foam::scalarField> Foam::movingConeTopoFvMesh::vertexMarkup
(
const pointField& p,
const scalar curLeft,
const scalar curRight
) const
{
Info<< "Updating vertex markup. curLeft: "
<< curLeft << " curRight: " << curRight << endl;
tmp<scalarField> tvertexMarkup(new scalarField(p.size()));
scalarField& vertexMarkup = tvertexMarkup();
forAll(p, pI)
{
if (p[pI].x() < curLeft - SMALL)
{
vertexMarkup[pI] = -1;
}
else if (p[pI].x() > curRight + SMALL)
{
vertexMarkup[pI] = 1;
}
else
{
vertexMarkup[pI] = 0;
}
}
return tvertexMarkup;
}
src/topoChangerFvMesh/movingConeTopoFvMesh/movingConeTopoFvMesh.C
108
 Classify the points by their positions

109. vertexMarkup 109
curLeft curRight
-1 1
0

110. References
[1] Roll Motion of a Box and Interaction with Free-Surface
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2009/ArashEslamdoost/RollMotionofaBoxandInteracti
onwithFreeSurface.pdf
[2] A tutorial on how to use Dynamic Mesh solver IcoDyMFOAM
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2007/PiroozMoradnia/OpenFOAM-rapport.pdf
[3] Mesh motion alternatives
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2009/AndreuOliverGonzalez/PresentationFINAL_Mesh
MotionAlternatives.pdf
[4] OpenFOAM project: A modification of the movingConeTopoFvMesh library
http://www.tfd.chalmers.se/~hani/kurser/OS_CFD_2008/ErikBjerklund/OpenFoamBjerklundE3.pdf
[5] Dynamic mesh in OpenFOAM
https://ilyasivkov.wordpress.com/2015/04/23/dynamic-mesh-in-openfoam/
110

111. This work is licensed under a Creative Commons
Attribution-ShareAlike 4.0 International License.
You should have received a copy of the license
along with this work. If not, see
<http://creativecommons.org/licenses/by-sa/4.0/>.
111