.. _dem_chutes_tutorial:
DEM granular flow chutes
------------------------
This tutorial shows how to create a three dimensional pure granular flow
simulation from a series of cylindrical chutes. The model setup is:
+------------------+--------------------------------------------+
| Property | Value |
+==================+============================================+
| geometry | 1.75 m x 0.94 m x 0.2 m |
+------------------+--------------------------------------------+
| mesh | 20 x 20 x 10 |
+------------------+--------------------------------------------+
| solid diameter | 12.5 mm (0.0125 m) |
+------------------+--------------------------------------------+
| solid density | 2500 kg/m\ :sup:`2` |
+------------------+--------------------------------------------+
| temperature | 298 K |
+------------------+--------------------------------------------+
| pressure | 101325 Pa |
+------------------+--------------------------------------------+
Create a new project
^^^^^^^^^^^^^^^^^^^^
- On the main menu, select ``New project``
- Create a new project by double-clicking on "Blank" template.
- Enter a project name and browse to a location for the new project.
- When prompted to enable SMS workflow, answer `No`, we will use the standard workflow for this tutorial.
.. _fig_new_project:
.. figure:: /media/gui_new_project.png
:width: 8cm
:alt: Create project
Select model parameters
^^^^^^^^^^^^^^^^^^^^^^^
On the ``Model`` pane:
- Enter a descriptive text in the ``Description`` field
- Select "Discrete Element Model (MFiX-DEM)" in the ``Solver`` drop-down menu.
- Check the ``Disable Fluid Solver`` checkbox.
.. _fig_model_param:
.. figure:: /media/gui_dem_chutes_model.png
:width: 8cm
:alt: Select model parameters
Enter the geometry
^^^^^^^^^^^^^^^^^^
On the ``Geometry`` pane:
- Create the cylindrical geometry by pressing |geometry|
-> ``primitives`` -> ``cylinder``
- Enter ``0.1`` meters for the cylinder radius
- Enter ``30`` for the cylinder resolution
.. _fig_add_cylinder:
.. figure:: /media/gui_dem_chutes_geo1.png
:width: 8cm
:alt: add cylinder
- Create another cylindrical geometry by pressing |geometry|
-> ``primitives`` -> ``cylinder``
- Enter ``1.2`` meters for the cylinder height
- Enter ``0.08`` meters for the cylinder radius
- Enter ``30`` for the cylinder resolution
- Subtract the smaller radius cylinder from the larger radius cylinder
- Select the larger radius cylinder (named ``cylinder``)
- While holding the ``ctrl`` key, select the smaller radius cylinder (named
``cylinder1``)
- Press the |difference| (difference) button
.. _fig_difference:
.. figure:: /media/gui_dem_chutes_diff1.png
:width: 8cm
:alt: apply difference
- Slice the tube in half:
- Add a box: |geometry| -> ``primitives`` -> ``box``
- Change the ``Center X`` value to ``0.5`` m
- Change the ``Y Length`` to ``1.2`` m
- Select the tube (named ``difference``)
- While holding the ``ctrl`` key, select the box (named ``box``)
- Press the |difference| button
- Rotate the chute:
- Select the chute (named ``difference1``)
- Add a filter: |filter| -> ``transform``
- Enter a value of ``0.8`` m in the ``Translate Y`` field.
- Enter a value of ``70`` in the ``Rotation Z`` field.
.. _fig_add_transform:
.. figure:: /media/gui_dem_chutes_filter1.png
:width: 8cm
:alt: Add filter
- Copy the chute by pressing the |copy| button with the chute selected (named
``transform``)
- Enter a value of ``0.8`` in the ``Translate X`` field
- Enter a value of ``0.6`` in the ``Translate Y`` field
- Enter a value of ``120`` in the ``Rotation Z`` field
- Copy the chute again by pressing the |copy| button with the chute selected
(named ``transform1``)
- Enter a value of ``0.0`` in the ``Translate X`` field
- Enter a value of ``0.3`` in the ``Translate Y`` field
- Enter a value of ``70`` in the ``Rotation Z`` field
- Press the ``Autosize`` button to fit the domain extents to the geometry
.. figure:: /media/gui_dem_chutes_geo_final.png
:width: 8cm
:alt: enter cylinder input
Enter the mesh
^^^^^^^^^^^^^^
On the ``Mesh`` pane:
- On the ``Background`` sub-pane
- Enter ``20`` for the x cell value
- Enter ``20`` for the y cell value
- Enter ``10`` for the z cell value
Create regions for initial and boundary condition specification
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Select the ``Regions`` pane.
- Create a region to be used for the wall boundary condition
- Click the |all_region| (all) button to create a new region
- Enter a name for the region in the ``Name`` field ("walls")
- Change the color by pressing the ``Color`` button
- Check the ``Select facets (STL)`` checkbox
- Create a region to be used as the mass inflow boundary condition
- Click the |top_region| (top) button to create a new region
- Enter a name for the region in the ``Name`` field ("inlet")
- Enter a value of ``-0.4`` m in the ``From X`` field
- Enter a value of ``-0.2`` m in the ``To X`` field
Create a solid
^^^^^^^^^^^^^^
On the ``Solids`` pane:
- Click the |add| button to create a new solid
- Enter a descriptive name in the ``Name`` field ("glass beads")
- Enter the particle diameter of ``1/80`` m in the ``Diameter`` field
- Enter the particle density of ``2500`` kg/m\ :sup:`2` in the ``Density`` field
On the ``DEM`` sub pane:
- check the ``Enable automatic particle generation`` checkbox
and keep defaults values for all other settings.
Create Initial Conditions
^^^^^^^^^^^^^^^^^^^^^^^^^
On the ``Initial conditions`` pane leave the default initial condition.
Create Boundary Conditions
^^^^^^^^^^^^^^^^^^^^^^^^^^
On the ``Boundary conditions`` pane:
- Create a new Boundary condition by clicking the |add| button
- On the ``Select region`` dialog, select "Mass Inflow" from the
``Boundary type`` drop-down menu
- Select the "inlet" region and click ``OK``
- On the ``glass beads`` sub-pane:
- Enter a value of ``0.1`` in the ``volume fraction`` field.
- Enter a velocity in the ``Y-axial velocity``
field of ``-0.1`` m/s
- Create another Boundary condition by clicking the |add| button
- On the ``Select region`` dialog, select "No Slip Wall" from the
``Boundary type`` combo-box
- Select the "walls" region and click ``OK``
Select output options
^^^^^^^^^^^^^^^^^^^^^
On the ``Output`` pane:
- On the ``Basic`` sub-pane, check the
``Write VTK output files (VTU/VTP)`` check box
- Select the ``VTK`` sub-pane
- Create a new output by clicking the |add| button
- Select ``Particle Data`` in the ``Output type`` combo box.
- Select the "Background IC" region from the list to save all the cell data
- Click ``OK`` to create the output
- Enter a base name for the ``*.vtp`` files in the ``Filename base``
field
- Change the ``Write interval`` to ``0.1`` seconds
- Select the ``Diameter`` and ``Translational Velocity`` check boxes.
Run the project
^^^^^^^^^^^^^^^
- Save project by clicking |save| button
- Run the project by clicking the |play| button
- On the ``Run`` dialog, select the default executable from the list
- Click the ``Run`` button to actually start the simulation
View results
^^^^^^^^^^^^
Results can be viewed, and plotted, while the simulation is running.
- Create a new visualization tab by pressing the |add| in the upper
right hand corner.
- Select an item to view, such as plotting the time step (dt) or click
the ``VTK`` button to view the vtk output files.
.. figure:: /media/gui_dem_chutes_results.png
:width: 8cm
:alt: new boundary condition
.. include:: /icons.rst