244 lines
6.5 KiB
Markdown
244 lines
6.5 KiB
Markdown
# 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 **20000** 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 drum.
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* **20000** particles with **4 mm** diameter, at the rate of 20000 particles/s for 1 sec.
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<html>
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<body>
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<div align="center"><b>
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a view of the tote-blender while rotating
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</div></b>
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<div align="center">
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<img src="sample sample sample sample", width=700px>
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</div>
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</body>
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</html>
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# Setting up the Case
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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.
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## Defining particles
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Then in the `caseSetup/sphereShape` the diameter and the material name of the particles are defined.
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```C++
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// names of shapes
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names (sphere1);
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// diameter of shapes (m)
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diameters (0.004);
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// material names for shapes
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materials (prop1);
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```
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## Particle Insertion
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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.
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<div align="center">
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in <b>caseSetup/particleInsertion</b> file
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</div>
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```C++
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// positions particles
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positionParticles
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{
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// ordered positioning
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method positionOrdered;
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// maximum number of particles in the simulation
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maxNumberOfParticles 40000;
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// perform initial sorting based on morton code?
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mortonSorting Yes;
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// box for positioning particles
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box
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{
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// lower corner point of the box
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min (-0.06 -0.06 0.08);
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// upper corner point of the box
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max (0.06 0.06 0.18);
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}
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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 rotating drum. Since we are defining 1 material for simulation, the interaction matrix is 1x1 (interactions are symetric).
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```C++
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// a list of materials names
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materials (prop1);
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// density of materials [kg/m3]
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densities (1000.0);
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contactListType sortedContactList;
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model
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{
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contactForceModel nonLinearNonLimited;
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rollingFrictionModel normal;
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/*
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Property (prop1-prop1);
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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
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mur (0.1);
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}
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```
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## Settings
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### Geometry
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In the `settings/geometryDict` file, the geometry and axis of rotation is defined for the drum. 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++
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surfaces
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{
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enterGate
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{
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// type of wall
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type planeWall;
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// coords of wall
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p1 (-0.05 -0.05 0.3);
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p2 (-0.05 0.05 0.3);
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p3 ( 0.05 0.05 0.3);
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p4 (0.05 -0.05 0.3);
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// material of wall
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material prop1;
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// motion component name
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motion rotAxis;
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}
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cylinderinlet
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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
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material prop1;
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// motion component name
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motion rotAxis;
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}
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coneShelltop
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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 0.2);
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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
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material prop1;
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// motion component name
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motion rotAxis;
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}
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cylinderShell
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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 0.1);
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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
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material prop1;
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// motion component name
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motion rotAxis;
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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
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material prop1;
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// motion component name
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motion rotAxis;
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}
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/*
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This is a plane wall at the exit of silo
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*/
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cylinderoutlet
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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
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material prop1;
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// motion component name
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motion rotAxis;
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}
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exitGate
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{
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type planeWall;
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p1 (-0.05 -0.05 0);
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p2 (-0.05 0.05 0);
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p3 ( 0.05 0.05 0);
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p4 (0.05 -0.05 0);
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material prop1;
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motion rotAxis;
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}
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}
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```
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### Rotating Axis Info
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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**.
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```C++
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rotatingAxisMotionInfo
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{
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rotAxis
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{
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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 3; // rotation speed (rad/s)
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}
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}
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```
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## Performing Simulation
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To perform simulations, enter the following commands one after another in the terminal.
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Enter `$ particlesPhasicFlow` command to create the initial fields for particles.
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Enter `$ geometryPhasicFlow` command to create the Geometry.
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At last, enter `$ sphereGranFlow` command to start the simulation.
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After finishing the simulation, you can use `$ pFlowtoVTK` to convert the results into vtk format storred in ./VTK folder. |