305 lines
7.9 KiB
Markdown
305 lines
7.9 KiB
Markdown
# Tote Blender simulation (v-1.0)
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## Problem Definition
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The problem is to simulate a double pedestal tote blender (mixer) 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 **0.00002 s**. There is one type of particle in this blender. Particles are positioned before the start of simulation to fill the blender.
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* **24000** particles with **5 mm** diameter are positioned, in order, and let to be settled under gravity. After settling particles, this blender starts to rotate at t=**1s**.
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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="https://github.com/PhasicFlow/phasicFlow/blob/media/media/Tote-blender.gif", width=700px>
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</div>
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<div align="center"><i>
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particles are colored according to their velocity
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</div></i>
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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 files are stored into two folders: `caseSetup`, `setting` (see the above folders). Unlike the previous cases, this case does not have the `stl` file and the surfaces are defined based on the built-in utilities in phasicFlow. See next the section for more information on how we can setup the geometry and its rotation.
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## Geometry
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### Defining rotation axis
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In file `settings/geometryDict` the information of rotating axis and speed of rotation are defined. The rotation of this blender starts at time=**0.5 s** and ends at time=**9.5 s**.
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```C++
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// information for rotatingAxis motion model
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rotatingAxis
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{
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axisOfRotation
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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 1.5708; // rotation speed ==> 15 rad/s
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// Start time of Geometry Rotating (s)
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startTime 0.5;
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// End time of Geometry Rotating (s)
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endTime 9.5;
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}
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}
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```
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### Surfaces
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In `settings/geometryDict` file, the surfaces and motion component of each surface are defined to form a rotating tote-blender. The geometry is composed of top and bottom cylinders, top and bottom cones, a cylindrical shell and top and bottom Gates.
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```C++
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surfaces
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{
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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
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p1 (0.0 0.0 0.3);
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// end point of cylinder axis
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p2 (0.0 0.0 0.301);
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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 0.0001;
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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 cylinderWall;
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p1 (0.0 0.0 0.28);
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p2 (0.0 0.0 0.3);
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radius1 0.03;
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radius2 0.03;
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resolution 36;
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material solidProperty;
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motion axisOfRotation;
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}
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coneShelltop
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{
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type cylinderWall;
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p1 (0.0 0.0 0.2);
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p2 (0.0 0.0 0.28);
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radius1 0.1;
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radius2 0.03;
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resolution 36;
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material solidProperty;
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motion axisOfRotation;
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}
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cylinderShell
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{
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type cylinderWall;
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p1 (0.0 0.0 0.1);
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p2 (0.0 0.0 0.2);
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radius1 0.1;
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radius2 0.1;
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resolution 36;
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material solidProperty;
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motion axisOfRotation;
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}
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coneShelldown
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{
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type cylinderWall;
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p1 (0.0 0.0 0.02);
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p2 (0.0 0.0 0.1);
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radius1 0.03;
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radius2 0.1;
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resolution 36;
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material solidProperty;
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motion axisOfRotation;
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}
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bottomCylinder
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{
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type cylinderWall;
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p1 (0.0 0.0 0.0);
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p2 (0.0 0.0 0.02);
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radius1 0.03;
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radius2 0.03;
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resolution 36;
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material solidProperty;
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motion axisOfRotation;
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}
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exitGate
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{
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type cylinderWall;
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p1 (0.0 0.0 -0.001);
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p2 (0.0 0.0 0.0);
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radius1 0.03;
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radius2 0.0001;
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resolution 36;
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material solidProperty;
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motion axisOfRotation;
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}
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}
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```
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## Defining particles
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### Diameter and material of spheres
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In the `caseSetup/shapes` the diameter and the material name of the particles are defined.
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<div align="center">
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in <b>caseSetup/shapes</b> file
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</div>
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```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);
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// material name for shapes
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materials (solidProperty);
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```
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### Particle positioning before start of simulation
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Particles are positioned before the start of simulation. The positioning can be ordered or random. Here we use ordered positioning. 24000 particles are positioned in a cylinderical region inside the tote-blender.
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<div align="center">
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in <b>settings/particlesDict</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 25001;
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// perform initial sorting based on morton code?
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mortonSorting Yes;
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// cylinderical region for positioning particles
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cylinder
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{
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p1 (0.0 0.0 0.09);
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p2 (0.0 0.0 0.21);
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radius 0.09;
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}
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positionOrderedInfo
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{
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// minimum space between centers of particles
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diameter 0.005;
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// number of particles in the simulation
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numPoints 24000;
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// axis order for filling the space with particles
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axisOrder (x y z);
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}
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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. Since we are defining 1 material type in the simulation, the interaction matrix is 1x1 (interactions are symmetric).
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```C++
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// a list of materials names
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materials (solidProperty);
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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 (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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// 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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# Performing Simulation and previewing the results
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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 stored in ./VTK folder.
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