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# Problem Definition
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The problem is to simulate a double pedestal tote blender with the diameter **0.03 m** and **0.1 m** respectively, the length **0.3 m** , rotating at **28 rpm** . This blender is filled with **24000** Particles. The timestep for integration is **0.00001 s** . There is one type of Particle in this blender that are being inserted during simulation to fill the blender.
* **24000** particles with **5 mm** diameter, at the rate of 24000 particles/s for 1 sec. َAfter settling particles, this blender starts to rotate at t=**1s**. For better and faster performace in simulations where the number of particles is very large, the format of the files is saved as **ASCII** .
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< html >
< body >
< div align = "center" > < b >
a view of the tote-blender while rotating
< / div > < / b >
< div align = "center" >
< img src = "sample sample sample sample" , width = 700px >
< / div >
< / body >
< / html >
# 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 are sotred in two folders: `caseSetup` , `setting` . (see the above folders). Unlike the previous cases, this case does not have the `stl` file. and the geometry is described in the `geometryDict` file.
## Defining particles
Then in the `caseSetup/sphereShape` the diameter and the material name of the particles are defined.
```C++
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// name of shapes
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names (sphere1);
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// diameter of shapes (m)
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diameters (0.005);
// material name for shapes
materials (solidProperty);
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```
## Particle Insertion
In this case we have a region for ordering particles. These particles are placed in this blender. For example the script for the inserted particles is shown below.
< div align = "center" >
in < b > caseSetup/particleInsertion< / b > file
< / div >
```C++
// positions particles
positionParticles
{
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// ordered positioning
method positionOrdered;
// maximum number of particles in the simulation
maxNumberOfParticles 25001;
// perform initial sorting based on morton code?
mortonSorting Yes;
// cylinder for positioning particles
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cylinder
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{
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// Coordinates of top cylinderRegion (m,m,m)
p1 (0.0 0.0 0.09);
p2 (0.0 0.0 0.21);
// radius of cylinder
radius 0.09;
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}
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positionOrderedInfo
{
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// minimum space between centers of particles
diameter 0.005;
// number of particles in the simulation
numPoints 24000;
// axis order for filling the space with particles
axisOrder (x y z);
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}
}
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```
## Interaction between particles
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In `caseSetup/interaction` file, material names and properties and interaction parameters are defined: interaction between the particles of Tote Blender. Since we are defining 1 material for simulation, the interaction matrix is 1x1 (interactions are symetric).
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```C++
// a list of materials names
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materials (solidProperty);
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// density of materials [kg/m3]
densities (1000.0);
contactListType sortedContactList;
model
{
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contactForceModel nonLinearNonLimited;
rollingFrictionModel normal;
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/*
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Property (solidProperty-solidProperty);
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*/
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// Young modulus [Pa]
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Yeff (1.0e6);
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// Shear modulus [Pa]
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Geff (0.8e6);
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// Poisson's ratio [-]
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nu (0.25);
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// coefficient of normal restitution
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en (0.7);
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// coefficient of tangential restitution
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et (1.0);
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// dynamic friction
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mu (0.3);
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// rolling friction
mur (0.1);
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}
```
## Settings
### Geometry
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In the `settings/geometryDict` file, the geometry and axis of rotation is defined for the blender. The geometry is composed of a cylinder inlet and outlet, cone shell top and down, a cylinder shell and enter and exit Gate.
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```C++
surfaces
{
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topGate
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{
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// type of wall
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type cylinderWall;
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// begin point of cylinder axis
p1 (0.0 0.0 0.3);
// end point of cylinder axis
p2 (0.0 0.0 0.301);
// radius at p1
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radius1 0.03;
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// radius at p2
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radius2 0.0001;
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// material of wall
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material solidProperty;
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// motion component name
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motion axisOfRotation;
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}
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topCylinder
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{
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// type of the wall
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type cylinderWall;
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// begin point of cylinder axis
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p1 (0.0 0.0 0.28);
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// end point of cylinder axis
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p2 (0.0 0.0 0.3);
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// radius at p1
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radius1 0.03;
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// radius at p2
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radius2 0.03;
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// number of divisions
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resolution 36;
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// material name of this wall
material solidProperty;
// motion component name
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motion axisOfRotation;
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}
coneShelltop
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{
// type of the wall
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type cylinderWall;
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// begin point of cylinder axis
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p1 (0.0 0.0 0.2);
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// end point of cylinder axis
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p2 (0.0 0.0 0.28);
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// radius at p1
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radius1 0.1;
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// radius at p2
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radius2 0.03;
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// number of divisions
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resolution 36;
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// material name of this wall
material solidProperty;
// motion component name
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motion axisOfRotation;
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}
cylinderShell
{
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// type of the wall
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type cylinderWall;
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// begin point of cylinder axis
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p1 (0.0 0.0 0.1);
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// end point of cylinder axis
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p2 (0.0 0.0 0.2);
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// radius at p1
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radius1 0.1;
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// radius at p2
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radius2 0.1;
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// number of divisions
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resolution 36;
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// material name of this wall
material solidProperty;
// motion component name
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motion axisOfRotation;
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}
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coneShelldown
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{
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// type of the wall
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type cylinderWall;
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// begin point of cylinder axis
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p1 (0.0 0.0 0.02);
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// end point of cylinder axis
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p2 (0.0 0.0 0.1);
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// radius at p1
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radius1 0.03;
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// radius at p2
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radius2 0.1;
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// number of divisions
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resolution 36;
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// material name of this wall
material solidProperty;
// motion component name
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motion axisOfRotation;
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}
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bottomCylinder
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{
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// type of the wall
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type cylinderWall;
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// begin point of cylinder axis
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p1 (0.0 0.0 0.0);
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// end point of cylinder axis
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p2 (0.0 0.0 0.02);
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// radius at p1
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radius1 0.03;
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// radius at p2
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radius2 0.03;
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// number of divisions
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resolution 36;
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// material name of this wall
material solidProperty;
// motion component name
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motion axisOfRotation;
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}
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exitGate
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{
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// type of the wall
type cylinderWall;
// begin point of cylinder axis
p1 (0.0 0.0 -0.001);
// end point of cylinder axis
p2 (0.0 0.0 0.0);
// radius at p1
radius1 0.03;
// radius at p2
radius2 0.0001;
// number of divisions
resolution 36;
// material name of this wall
material solidProperty;
// motion component name
motion axisOfRotation;
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}
}
```
### Rotating Axis Info
In this part of `geometryDict` the information of rotating axis and speed of rotation are defined. Unlike the previous cases, the rotation of this blender starts at time=**0 s**.
```C++
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// information for rotatingAxisMotion motion model
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rotatingAxisMotionInfo
{
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axisOfRotation
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{
p1 (-0.1 0.0 0.15); // first point for the axis of rotation
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p2 ( 0.1 0.0 0.15); // second point for the axis of rotation
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omega 1.5708; // rotation speed ==> 15 rad/s
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// Start time of Geometry Rotating (s)
startTime 0.5;
// End time of Geometry Rotating (s)
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endTime 9.5;
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}
}
```
## Performing Simulation
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 storred in ./VTK folder.
