3bc35e9e62
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| .. | ||
| caseSetup | ||
| settings | ||
| stl | ||
| ReadMe.md | ||
ReadMe.md
Problem Definition
The problem is to simulate a Rotary Air-Lock Valve with below diminsions:
- Size of Cone:
- Cone Gate: 29.17 cm
- Cone Exit: 10.37 cm
- Size of Outer Exit: 9.42 cm
- External diameter of Circle: 20.74 cm There is one type of particle in this blender. Particles are poured into the inlet valve from t=0 s.
- 28000 particles with 5 mm diameter poured into the valve with rate of 4000 particles/s.
Setting up the Case
As it has been explained in the previous cases, the simulation case setup is based on text-based scripts. Here, the simulation case setup files are stored into three folders: caseSetup, setting, stl (see the above folders). See next the section for more information on how we can setup the geometry and its rotation.
Geometry
Defining rotation axis
In file settings/geometryDict the information of rotating axis and speed of rotation are defined. The rotation of this blender starts at time=0 s and ends at time=7 s.
// information for rotatingAxisMotion motion model
rotatingAxisMotionInfo
{
rotAxis
{
// first point for the axis of rotation
p1 (0.561547 0.372714 0.000);
// second point for the axis of rotation
p2 (0.561547 0.372714 0.010);
// rotation speed (rad/s)
omega 2.1;
// Start time of Geometry Rotating (s)
startTime 1.25;
// End time of Geometry Rotating (s)
endTime 7;
}
}
Surfaces
In settings/geometryDict file, the surfaces component are defined to form a Rotating Air-Lock Valve.
surfaces
{
gear
{
// type of the wall
type stlWall;
// file name in stl folder
file gear.stl;
// material name of this wall
material wallMat;
// motion component name
motion rotAxis;
}
surfaces
{
// type of the wall
type stlWall;
// file name in stl folder
file surfaces.stl;
// material name of this wall
material wallMat;
// motion component name
motion none;
}
Defining particles
Diameter and material of spheres
In the caseSetup/sphereShape the diameter and the material name of the particles are defined.
// names of shapes
names (sphere);
// diameter of shapes
diameters (0.005);
// material names for shapes
materials (sphereMat);
Particle positioning before start of simulation
// positions particles
positionParticles
{
// creates the required fields with zero particles (empty).
method empty;
// maximum number of particles in the simulation
maxNumberOfParticles 50000;
// perform initial sorting based on morton code?
mortonSorting Yes;
}
Interaction between particles
In caseSetup/interaction file, material names and properties and interaction parameters are defined. Since we are defining 1 material type in the simulation, the interaction matrix is 2x2 (interactions are symmetric).
// a list of materials names
materials (sphereMat wallMat);
// density of materials [kg/m3]
densities (1000 2500);
contactListType sortedContactList;
model
{
contactForceModel nonLinearNonLimited;
rollingFrictionModel normal;
/*
Property (sphereMat-sphereMat sphereMat-wallMat
wallMat-wallMat);
*/
// Young modulus [Pa]
Yeff (1.0e6 1.0e6
1.0e6);
// Shear modulus [Pa]
Geff (0.8e6 0.8e6
0.8e6);
// Poisson's ratio [-]
nu (0.25 0.25
0.25);
// coefficient of normal restitution
en (0.7 0.8
1.0);
// coefficient of tangential restitution
et (1.0 1.0
1.0);
// dynamic friction
mu (0.3 0.35
0.35);
// rolling friction
mur (0.1 0.1
0.1);
}
Performing Simulation and previewing the results
To perform simulations, enter the following commands one after another in the terminal.
Enter $ particlesPhasicFlow command to create the initial fields for particles.
Enter $ geometryPhasicFlow command to create the geometry.
At last, enter $ sphereGranFlow command to start the simulation.
After finishing the simulation, you can use $ pFlowtoVTK to convert the results into vtk format stored in ./VTK folder.