.. _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 ^^^^^^^^^^^^^^^^^^^^ - (:numref:`fig_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 ^^^^^^^^^^^^^^^^^^^^^^^ (:numref:`fig_model_param`): 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: - (:numref:`fig_add_cylinder`): 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 - (:numref:`fig_difference`): Subtract the smaller radius cylinder from the larger radius cylinder by - Select the larger radius cylinder (named ``cylinder``) - While holding the ``ctrl`` key, select the smaller radius cylinder (named ``cylinder1``) - Press the |difference| button .. _fig_difference: .. figure:: /media/gui_dem_chutes_diff1.png :width: 8cm :alt: apply difference - Slice the tube in half by: - 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 by: - Select the chute (named ``difference1``) - (:numref:`fig_add_transform`): 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| 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| 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