Tut3-Rock-box_v2.5

EDEM Tutorial: Rock Box Simulation

EDEM Tutorial: Rock Box

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Introduction This introductory tutorial shows how to set-up and analyze an EDEM simulation. The model used here is a rock box. The script consists of two parts – – the first part (page (page 4) 4) describes a simplified simulation set up suitable for EDEM Classroom version. It can be established quickly and the simulation time is low. It should be noticed that the model is setup to run within the EDEM Classroom limitation of 10,000 model elements. A high fidelity f idelity model is described in part 2 ( page 22). 22). This extended simulation can only be run in EDEM Professional version as it requires more model elements. The simulation time is also longer (~40 minutes on 2 CPU’s). CPU’s). The users of EDEM Professional can run both Parts 1 and Parts 2.

The main focus in on: on: 

Creation of multiple particle types and shapes



Creation of Moving Plane contact models for conveyors conveyors



Analysis of geometry geometry to choose the appropriate parameters for velocities velocities of of conveyor belts



Creation of the mass flow sensor and a bin bin group



Generation of graphs and pie charts to analyze simulation’s features. features .

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PART I – I – Initial Initial setup 1. Start EDEM. 2. Go to File > Save As… 3. Select a location on the local machine (e.g. C:\EDEM_Tutorials). C:\EDEM_Tutorials). 4. Enter a file name (e.g. Rock_box.dem) Rock_box.dem) and click Save.

EDEM Creator: Setting up the model Step 1: Set the Global Model Parameters Choose the units The first step in creating the model is to set the units used throughout EDEM. 1. Go to the Tools > Options… menu and select the Units tab. 2. Change the following measurement units: 

Angle to radians (rad) rad)



Angular velocity to rad/s



Length to mm



Mass to kg



Mass Flow Rate to kg/s



Velocity to m/s

3. Click OK.

Enter the model title and description The model title and description will appear in the Data Browser window. 1. Click on the Globals Globals tab in the Tabs pane. pane. 2. Enter the title Rock Box in in the Title field f ield in the Simulation section.

Install the EDEM materials database 1. In Windows go to Start > DEM Solutions Solutions > EDEM 2.5 and select Install external libraries to My Documents. Documents. 2. When you navigate navigate My Documents folder folder you will notice notice that new folder EDEM_2.5.0 was created. To make sure that the materials database is already available in your new simulation: 3. Go back to EDEM and navigate to: Tools > O ptions… > File Locations. 4. In Materials Database Database section, click Browse Browse button and go to EDEM_2.5.0 EDEM_2.5.0 folder in My Documents. 5. Select materialsDB.ddb and click OK. When you use EDEM later, the database would already be imported so you do not have to install libraries every time you run EDEM. Page 4 of 32


Set the contact models The Physics section lists contact models and forces. A contact model describes how elements behave when they come into contact with one another. 1. Select Particle to Particle from the Interaction drop-down list and make sure Hertz-Mindlin (no slip) is slip) is listed. 2. Select Particle to Geometry from Geometry from the Interaction I nteraction drop-down drop-down list. 3. Click the

button then select the Moving Plane contact Plane contact model.

4. Select Moving Plane Plane from from the the list list,, then then clic click k the the up up but butto ton n Plane contact model is calculated before Hertz-Mindlin: Hertz-Mindlin:

, so that that Mov Movin ing g

Set the gravity and define the materials Every particle or section of geometry used in a model is made of a particular material. All materials and the interactions between them must be defined in the Materials section. 1. Check that Gravity is set to -9.81m/s -9.81m/s2 in the z-direction. 2. Click the

button in the Materials section to create a new material.

3. Click the

button and rename the material to r o c k . Click OK.

4. Set the Poisson's Ratio, Shear Modulus and Density as shown below:

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EDEM Tutorial: Rock Box Now define the rock box and conveyor belt materials. These are made of steel and rubber – – materials very similar to the high and low-stiffness materials defined in EDEM’s materials database. database . They can be transferred from there. 1. Click the Transfer button. The Material/Interactions Transfer dialog will appear 2. Expand the Materials Materials tree in the Materials Database window and select highstiffness. stiffness. 3. Click the left arrow to copy the material material into your model. Click OK to close the window. 4. Select the the high-stiffness high-stiffness material and click the button to rename the material to steel . 5. Repeat and select low-stiffness material low-stiffness material and re-name to r u b b e r .

Define the interactions between the materials 1. Select rock from rock from the drop-down list at the top t op of the materials section. 2. Click the button in the Interaction section. Select rock rock when prompted. This will define the interaction between elements both made of the material rock. 3. Set the coefficients as follows:

4. Click the Interaction button a second time and select the material steel. This will define interaction between elements made of rock (particles) with elements made of steel (rock box). 5. Set the coefficients as follows:

6. Repeat and set the rock-rubber interaction using the same interaction coefficients. Page 6 of 32


Step 2: Define the Base Particles All types of particle particle used in a model model are defined defined in the Particles pane. In this tutorial you need to create 2 different particle shapes. It is done in order to show the variety of r ock particles shapes in reality.

Create new particle types 1. Click the Particles tab. 2. Click the

button in Select Particle section to create a new particle type.

3. Click the

button and rename the particle rock particle_1 . particle_1

4. Repeat points points 2. and and 3. to create another particle particle type - rock particle_2 particle_2 .

Define the surfaces and properties Particles are made up of one or more spherical surfaces. First type of rock particle consists of three spheres. 1. Select rock particle_1 from drop-down menu. 2. In the Surfaces Surfaces section, section, modify first surface (default name name surface 0 ) by setting the Radius to 40mm and 40mm and Position X, Y, Z to (0, (0, 0, 30) 30) mm. 3. Click the

button in the Surfaces section to create a second surface.

4. Set the Radius of this surface to 40 mm and mm and the Position to be (-30, ( -30, 0, -30) -30) mm. The second surface is offset from the first. 5. Check the Highlight Surface box Surface box in Viewer Controls on the right of the Viewer to help distinguish the surfaces. 6. Create a third surface, surface, setting setting the Radius Radius to 40 mm, ( 30, 0, -30) mm, the Position to (30, -30) mm. The particle should have a triangular shape and look like this:

7. Set the Material to rock. rock. 8. Click the Calculate Calculate Properties Properties button button and pick pick the Surfaces option Surfaces option in the dialog that appears. Make sure that the Automatically Automatically Center Particle box Particle box is checked and click OK.

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EDEM Tutorial: Rock Box You should notice that the values of Position X, Y, Z have been modified slightly. It happens because we decided to center a particle at the beginning of the coordinate system. 9. Now you need to create surfaces for rock particle_2. particle_2. To do so follow the previous instructions with the specifications presented in t he table below. Name

rock particle_1

rock particle_2

Surface

0

1

2

0

1

2

3

Radius (mm)

40

40

40

40

40

40

40

Position X (mm)

0

-30

30

0

30

0

30

Position Y (mm)

0

0

0

0

0

0

0

Position Z (mm)

30

-30

-30

0

0

30

30

The shape that you should obtain is presented above. Note that we have created triangular and square particles to highlight the variety of rock particles shapes in nature.

Step 3: Define the Geometry Next step is to define the rock box geometry used in the model.

Import the rock box geometry The rock box geometry has been created in a CAD package and it can be imported into EDEM. 1. Click on the Geometry tab. 2. Click the Import button in the Sections part. 3. Navigate to the file rock_box1.stl in rock_box1.stl in the tutorial folder and import it. 4. When prompted prompted to, set the Units Units of measurement measurement to Millimeters. Millimeters. 5. When the Geometry Import Parameters dialog appears appears leave all the settings settings at the default values and click OK. The geometry will appear in the Viewer. It is made up of four sections, which are listed in the Sections drop-down list. W hen any part is selected it is highlighted in red. 6. Re-name the geometry sections appropriately appropriately to: to: Feed_Conveyor Head_Pulley Rock_Box Receiving_Conveyor

7. In Details Details tab, set Type to Physical for all sections. 8. Change the Material to steel steel for the Rock_Box and rubber for the Head_Pulley and Conveyors.

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Configure the moving plane The conveyor model uses the Moving Plane contact model. This model simulates a linear motion of a geometry section, where the whole section moves at the same velocity. The contact model adds this linear velocity to the velocity of the geometry section only within the contact model. In other words, the geometry section does not actually move. 1. Go back back to the Globals tab. 2. Select the Moving Plane co Plane cont ntac actt mod model el then then clic click k the the con confi figu gure re butto button n

:

3. Click the button to add the Feed_Conveyor as the moving plane. Set the Linear Velocity as f ollows:

The components of velocity are chosen in this way so that the velocity magnitude in the direction of the belt travel is about 3.54 m/s . The belt is angled at 9.01 degrees to axis. The +Y view shows the angle of the top conveyor. In the image below, a protractor was used to measure the value of an angle (it can be done by going to: Analyst > Tools > Protractor).

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4. Click the button again to add the Receiving_Conveyor as as the moving plane. Set the Linear Velocity as follows:

The velocity of the receiving conveyor should be similar to the feed conveyor. By setting the views to +Z and – and –Y Y the angles of incline can be measured and the velocity components calculated.

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Setup the Head Pulley Motion 1. Return to the Geometry tab 2. Select Head_Pulley section Head_Pulley section and click on Dynamics tab. The dynamics need to be modified as Head_Pulley is a rotating part of the geometry. 3. In General section, click the

button and select Linear Rotation.

4. Leave Start and End Time a as s default, modify Initial Initial Velocity to 7.08 rad/s to match the linear velocity of the conveyor (3.54 m/s) as the radius of pulley is equal to 0.5m. 5. Now you need to specify the Axis of Rotation. Click button next to Start and move mouse cursor to the Viewer. Pick the point at the end of the shaft of roller, in the middle. For the End point, pick the point in the middle on the other end of the roller shaft. The easiest way to pick Start and End points, is by using +Y +Y and – Y Y Views respectively. respectively. See images on the next page for reference. Make sure that the points are selected carefully. Otherwise the axis of rotation would move and simulation would not produce the qualitative results.

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6. The values should be similar to:

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Modify the domain As in EDEM Classroom there is a limited number of model elements, it is necessary to decrease the domain in order to allow a simulation of higher number of particles. 1.

In Domain section (at the top), uncheck Auto Update from Geometry G eometry box.

2.

Set the domain as follows:

Create the particle factory plate Particle factories are used to define where, when and how particles appear in a simulation. All factories must be based on a section of geometry (whether 'real' or 'virtual'). This defines the area in the model that produces the particles. 1. Click the

button in the Sections part and select Polygon. Polygon.

2. Click the

button and rename the section Factory_plate .

3. Click on the Details tab and set the type to Virtual, Virtual, since the plate is not a physical part of the machinery. 4. Click on the Polygon tab tab and set the Number of Edges, Edges, X/Y/Z Center, Center, Rotation and Dimensions of the polygon as follows:

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Step 4: Create the Particle Factory Generally there should be one factory per each particles type. However all these factories (in this case two) can be based on one geometry (a polygon that was created in the previous step).

Create the particle factory 1. Click on the Factories tab. 2. Click the

button to create a New Factory 1 (default name).

3. Click the

button again to create New Factory 2.

Set the factory’s particle creation values For each factory that you have just created: 1. Set the Factory Type to dynamic and Select Unlimited Number. 2. In the Generation Rate section, select Target Mass and Mass and set the rate to 100kg/s and 120kg/s for New Factory 1 and New Factory 2, respectively.

Set the factory’s initial parameters 1. Select New Factory 1 from 1 from factories pull-down. 2. In the Parameters part, select the Factory_plate from Factory_plate from the t he Section pull-down. 3. Set the Type to fixed and click the configure button rock_particle1. rock_particle1.

then choose

4. Set the Size to fixed. fixed. All particles will have the same size. 5. Set the Position to random to random to ensure that the particles are randomly created over the entire plate area. 6. Set the Velocity to fixed the fixed then n clic click k the conf config igur ure e but butto ton n to set set the the vel veloc ocit ity y in xxdirection to 3.54 m/s. m/s. The particles will leave the factory with this velocity. 7. Repeat instructions 2. to 6. for New Factory 2 configuring the Type to rock_particle2. rock_particle2. 8. Select File > Save to save the final setup of the simulation. simulation.

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EDEM Simulator: Running Simulation Once the model has been set-up in the Creator we move to the Simulator to run it. 1. Clic Click k on the the Simu Simula lato torr butt button on

on the the tool toolba bar. r.

Step 1: Set the Time Options Set the time step The time step is the amount of time between iterations (calculations) (calculations) in the Simulator. The particles in this model are loosely packed for the majority of the simulation, so set a time step of 20% of the Rayleigh Time Step. To find out more about Rayleigh time step, refer to Appendi to Appendix x A: Estimating Simulation Simulation Time of Time of the EDEM Help. 1. Set the Fixed Time Step upper box box to 20%. 20%. The numerical value of the time step would be calculated automatically. automatically.

Set the simulation time and data write-out frequency The simulation time is the amount of real time your simulation represents. 1. In Simulation Simulation Time section, section, set the Total Time to 9s, 9s, to ensure that the steady state is reached. 2. Set the Target Save Interval to 0.02s to 0.02s to specify write-out frequency. Usually it is not necessary to write a data point for every iteration in a simulation. Doing so will usually result in a slow simulation and a very large amount of data being collected.

Step 2: Set the Grid options The grid options are used to t o optimize the simulation. 1. Set the Cell Size to 3 Rmin. Rmin. (Rmin = smallest particle radius in simulation) Note the number number of grid grid cells (Approx. (Approx. Number of Cells) is is stated below. below. The simulation results are not affected by the number of grid cells, only the time taken to reach them. The more grid cells a simulation uses the more system RAM is required. It is necessary to find a balance between RAM usage and simulation performance. For simulations with a narrow size distribution the ideal value will be between 2 – 3 Rmin, but for wider size distributions this will increase.

Step 3: Run the Simulation You are now ready to start the simulation. 1. Click Click the start start Progre Progress ss button button

at the bottom bottom of the simulation simulation window window..

2. If the Factory Warning dialog dialog pops out, out, click No for all factories. factories. 3. In Viewer Viewer Controls, Controls, click click the Refresh Viewer button or enable Auto Update at any point to update the Viewer and see how the simulation is progressing.

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EDEM Analyst: Analyzing Your Results The Analyst is used to review, examine and analyze the results of the simulation. 1. Clic Click k on the the Anal Analys ystt butt button on


2. Use the controls below below the main main window to rewind the simulation simulation to the first time step (use button). 3. Click

button to play through each time step of your simulation. simulation.

Step 1: Configuring the Display The options in the Model pane are used to configure how the different elements in your model appear.

Configure the geometry 1. Click on the Model tab to open the Model pane. 2. Experiment with with altering the geometry geometry display. display. To do that in Geometry section section change Type and then modify the Display options. Display Mode can be chosen to be Filled, Mesh or Points. Points. The Opacity can take values 0-1, 0-1, with 0 being completely transparent and 1 being solid. 3. Click Apply button to see the changes in Viewer window. 4. You can set the Display Display Mode to Filled with 0.3 Opacity to view the particles’ flow. Click Apply. 5. Before finishing, be sure the Display box Display box is unchecked for Factory_plate. Factory_plate. Click Apply.

Configure the particles The display of the particles can be altered in a similar way to that of the geometry. In addition, the particles can be represented using a number of different forms, like vectors, cones, streams, etc. 1. In the Particles Particles section of the Model Model tab, go to Representation pull-down menu and experiment with changing it to Vector or Cone and Cone and click Apply. 2. Change the Representation Representation to Stream. Stream. Click the button and in Streams section check Stream All Steps and Stream Fade checkboxes. 3. Click OK and then Apply button. 4. Play through the simulation. 5. Make sure that all particles types are displayed and set the Representation back to Default before Default before proceeding. Click Apply.

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Step 2: Coloring Elements The particles, geometry and contacts within your model can be colored in a variety of ways. Any section of geometry, particle, contact type or selection group can be colored independently.

Color the geometry according to section type 1. Click on the Coloring tab to open the Coloring pane. 2. In the Select Element section, set: 

Element to Geometry



Color by to Type



Type to Feed_Conveyor

3. In the Attribute Coloring section, set the Attribute to Velocity. Velocity. 4. Set the Min, Mid Mid and Max colors to the Blue, Green and Red and Red respectively. respectively. 5. For Min Min Value and Max Max Value check the Auto Update boxes. Update boxes. 6. Click the Apply button. 7. Repeat instructions 2 to 6 selecting Receiving_Conveyor Receiving_Conveyor and and Head_Pulley. 8. Click the Play button to view the velocity of moving moving parts of the geometry. geometry. Notice that only Roller is displayed as a moving part of the geometry. The velocity of conveyors is zero throughout the whole simulation. It happens because these geometries are not physically moving in the model, the Moving Plane contact model is used to represent this motion. 9. Before continuing change Type to All. All. 10. In Static Coloring section, choose Default Geometry Geometry and click Apply. The geometry changes the colors back to original.

Color the particles according to their velocity 1. Click on the Coloring tab to open the Coloring pane. 2. In the Select Element section, set: 

Element to Particle



Color by to Type



Type to All

3. In the Attribute Coloring section, set the Attribute to Velocity. Velocity. 4. Set the Min, Mid Mid and Max colors to the Blue, Green and Red and Red respectively. respectively. 5. Click the buttons next to the Min and Max Value fields – – this reads the current values y from the point in the simulation being displayed in the Viewer at the moment. Check Auto Update checkbox. Update checkbox. 6. Click the Apply button to color the particles. 7. Click the Show Legend checkbox Legend checkbox then click Apply. 8. Click the Play Play button to view the distribution of of velocity over over time.

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Step 3: Creating Selections Selections allow data to be extracted from a particular area or element in the domain. Using selections, you can monitor any element passing through a particular area (known as a “bin”) or track particular elements whereever they move within the domain. You can then display, color, graph or export data based on the selections.

Create a mass flow sensor We can examine the mass flow over time on the bottom conveyor by including a mass flow sensor. 1. Click on the Selection tab. 2. Click the

button then select Mass Flow Sensor .

3. In the Representat Representation ion section set Display Mode to Always. Always. 4. Set the properties properties of the bin group as as follows follows then click Apply: Apply:

Create a grid bin group We can also examine the increase of mass over time on the rock box. To do that, you need to create a bin group over it. 1. Click the

button then select Grid Bin Group. Group. Rename it R o c k _ B o x G r o u p .

2. Set the properties properties of the bin group as follows follows then click Apply: Apply:

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Define selection group queries A query is used to define a single element attribute, for example particle velocity, total force on a geometry section or number of collisions. To determine the total mass of particles accumulating in the rock box: 1. In Viewer Controls, Controls, set the Current Time to 0s (the beginning beginning of the simulation, simulation, when no particles are present in the rock box). 2. Click the Queries Edit Edit button in the Options section: section: 3. Expand the Particle Particle tree then select Mass. Mass. 4. Select Rock Particle in Particle in the Type menu and set Query Type to Total. 5. Select the Total Over Time option then click the displayed in the list at the bottom of the dialog. Click OK.

button. The query is

6. Note that you do not need to create a query for the mass flow sensor. To verify verify that, select Mass Flow Sensor 01 from Selection drop-down list. When you click on Queries Edit button, you will notice that a query Mass Flow Rate has been automatically automatically created.

Set selection group display options 1. Select the Rock_Box Group from Group from the drop down list then in the Representation section, click the Display Options Edit button. 2. Tick the On Screen Screen Query Query checkbox to display the mass in the viewer: viewer:

3. As you probably probably noticed, there is no need to do that for Mass Mass Flow Sensor as as the query already appears in the Viewer. 4. Click the play button button to view the results results in real time. As playback playback continues through the time-steps, bin group data is collected and displayed.

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Step 4: Plotting the graphs Plot a graph of mass flow rate on the bottom conveyor To plot a linear graph of mass flow rate of all particles changing over time on the bottom conveyor: 1. Clic Click k the the Crea Create te Grap Graph h butt button on

in the the tool toolba bar. r.

2. In Line Graph tab, set the parameters parameters as follows:

3. In the X-axis X-axis tab, ensure that Time Range Range covers whole simulation simulation time. 4. Click the Y-axis tab. tab. Set the Primary Primary Attribute Attribute to Mass Flow Rate. 5. Click Create Create Graph at the bottom to plot the graph. 6. To save the image go to File>Print Image…

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Plot the graph of total particle mass in the rock box A rectangular bin bin group over over the rock box registers registers the change of of total mass of the particles there. To plot the increase in mass over time in the rock box: 1. In Line Graph tab, set the parameters parameters as follows:

2. In the X-axis X-axis tab, ensure that Time Range Range covers whole simulation simulation time. 3. Click the Y-axis tab. tab. Set the Primary Primary Attribute Attribute to Mass and Mass and the Component to Total. Total. 4. Click Create Create Graph at the bottom to plot the graph. 5. To save the image go to File>Print Image…

From the graph, you can conclude that a steady state has not been reached yet. Page 21 of 32


PART II – II – Full Full simulation for EDEM Professional The basic simulation has already been prepared and analyzed for this tutorial. In Part 2 you will modify this for f or the full-scale case: 1. Open Rock_box.dem from Part 1. 2. Go to the EDEM Analyst, set set Current Current Time to 0 s. s. 3. Choose File > Export > Simulation Deck. 4. Choose a location (e.g. C:\EDEM_Tutorials) C:\EDEM_Tutorials) Rock_box_full.dem) Rock_box_full.dem) and click Save.

and

file

name

(e.g.

5. In the Export Export Options Options dialog that appears, appears, leave the default setting. Note, this will create the simulation file at t = 0 s. An input deck can be taken from any point of a simulation. It is useful to sometimes take the input from the last timestep to store the simulation results or share with other users. This is a single timestep and much smaller in file size than the full simulation. 6. Close this file and open Rock_box_full.dem from the folder.

EDEM Creator: Setting up the model Step 1: Define the Base Particles All types of particle particle used in a model model are defined defined in the Particles pane. In this part you need to create 3 different particle shapes. It is done in order to show the variety of rock particles shapes in reality.

Create new particle types 1. Click the Particles tab. 2. Click

button to remove the particle types created previously. previously.

3. Click the

button to create a new particle type.

4. Click the

button and rename the particle rock particle_1 . particle_1

5. Repeat points points 2. and 3. to create two more particle types: types: rock particle_2 particle_2 and rock particle_3 particle_3 .

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Define the surfaces and properties Particles are made up of one or more spherical surfaces. In this case we import CAD templates of rock particles of different shapes and fit spheres to the template. 1. Select Tools > Options… > Particle Display. 2. Click the Import button. You need to import three particle templates Rock_Template1.stl, Rock_Template1.stl, Rock_Template 2.stl and Rock_Template3.stl. Rock_Template3.stl. 3. When Import Options Options dialog appears, appears, set the measurement measurement units to Millimeters (mm) and click OK. 4. When the Geometry Geometry Import Parameters dialog appears, appears, leave all the settings at the default values and click OK. 5. Click the

button and rename the templates to Rock_Template1 , accordingly then click OK. Rock_Template2 and Rock_Template3 accordingly

6. To view the template, go to Viewer Controls on the right of the screen. In section Particles check the Show Template box. Template box. 7. Select Rock_Template1 from a dropdown dropdown list. 8. Go back to Particles Particles tab in Creator Creator panel. panel. Select Select rock_particle1 rock_particle1.. 9. Modify the Surfaces Surfaces section. section. The radii and positions positions of spheres spheres are presented presented in the table. 10. Repeat instructions 7-9 for two other particle types. Template

Rock_Template1

Rock_Template2

Rock_Template3

Particle Name

rock particle_1

rock particle_2

rock particle_3

Surface

0

1

2

0

1

2

0

1

2

3

Radius (mm)

25

25

25

25

20

20

25

25

25

25

Position X (mm)

0

-17

17

0

16

-16

-10

10

-10

10

Position Y (mm)

19 19

-9

-9

2

-8

-8

-10

-10

10

10

Position Z (mm)

0

0

0

0

0

0

0

0

0

0

11. For all particles, set the t he Material to rock. rock. 12. Click the Calculate Properties button and pick the Surfaces Surfaces option in the dialog that appears. The shapes that you should obtain along with the templates t emplates are presented below. Note that we have created two different triangular particles and a square one to highlight the variety of rock particles shapes.

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Step 2: Define the geometry The geometry used here is the same as in Part 1.

Modify the domain In EDEM Professional, there is no limit on model elements; therefore the domain can be extended.

1. Go to Geometry tab. 2. In Domain Domain section section check check the Auto Update from Geometry checkbox. In this way the whole geometry is included in the domain. Notice how the values of X, Y and Z have changed.

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Step 3: Create the Particle Factory Create the particle factory 1. Click on the Factories tab. 2. Remove the factories factories that already exist. 3. Click the

button three times to create three New Factories.

Set the factory’s particle creation values In this model, all types of rock particles are to be created at a rate of 100 kg per second. Therefore for each factory that you have just created: 1. Set the Factory Type to dynamic and select Unlimited Number . 2. In the Generation Rate section, select Target select Target Mass and Mass and set the rate to 100 to 100 kg/s. kg/s.

Set the factory’s initial parameters 1. Select New Factory 1 from 1 from factories pull-down. 2. In the Parameters part, select the Factory_plate from t he Section pull-down. Factory_plate from the 3. Set the Type to rock_particle1. rock_particle1.

fixed fixed and and

cli click ck the the

co config nfigur ure e

but butto ton n

4. Set the Size to random an random and d cli click ck the the conf config igur ure e but butto ton n 0.8 and 0.8 and Maximum to 1.2 to 1.2 to specify size distribution.

to choo choose se

to set set the the Mini Minimu mum m to

5. Set the Position to random. random. 6. Set the Velocity to fixed the fixed then n clic click k the conf config igur ure e but butto ton n to set set the the vel veloc ocit ity y in xxdirection to 3.54m/s. The particles will leave the factory with this velocity. 7. Repeat instructions instructions 2-6 for New Factory Factory 2 and New Factory 3, configuring the Type to rock_particle2 and rock_particle3, respectively. 8. Select File > Save to save the final setup of the simulation. simulation.

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EDEM Simulator: Running Simulation Once the model has been set-up in the Creator we move to the Simulator to run it. 1. Clic Click k on the the Simu Simula lato torr butt button on


Step 1: Set the Time Options Set the time step 1. Set the Fixed Time Step upper box to 20%. 20%. The numerical value of the time step would be calculated automatically. automatically.

Set the simulation time and data write-out frequency The simulation time is the amount of real time your simulation represents. 1. In Simulation Simulation Time section, section, set the Total Time to 10s. 10s. 2. Set the Target Save Interval to 0.02s to 0.02s to specify write-out frequency.

Step 2: Set the Grid options The grid options are used to t o optimize the simulation. 1. Set the Cell Size to 3 Rmin. Rmin.

Step 3: Run the Simulation You are now ready to start the simulation. 1. Click Click the start Progress Progress button

at the bottom bottom of the simulatio simulation n window window..

2. In Viewer Viewer Controls, click the Refresh Viewer button or enable Auto Update at any point to update the Viewer and see how the simulation is progressing. 3. The simulation simulation should should not take longer longer than about 20 minutes.

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EDEM Analyst: Analyzing Your Results The Analyst is used to review, examine and analyze the results of the simulation. Part of the analysis has been performed in Part 1 already. Refer to instructions starting at page 15.

Step 1: Configuring the Display Configure the particles 1. In the Particles section section of the Model Model tab, go to Representation Representation pull-down menu menu and experiment with changing it to Vector, Cone or Streams as before. 2. Click Apply button. 3. Watch the simulation step step by step. Notice that it is impossible impossible to distinguish between types of particles anymore. The images below show two time-steps shots for Vector representation.

4. Browse to the Analyst Analyst > Model Model > Particles Particles tab, tab, set a. Type to rock particle_1 b. Click Options set Template to Rock_Template1. Click OK. c. Change the Representation to Template and click Apply. d. Repeat for rock particle_2 particle_2 and 3 and and set associated associated templates templates 2 and 3.

The particles are now displayed by their associated CAD templates.

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Step 2: Coloring Elements Color the particles according to their velocity 1. Click on the Coloring tab to open the Coloring pane. 2. In the Select Element section, set: 

Element to Particle



Color by to Type



Type to All

3. In the Attribute Coloring Coloring section, set set the Attribute to Velocity. Velocity. 4. Set the Min, Mid and Max colors to the Blue, Green and Red and Red respectively. respectively. 5. Click the buttons next to the Min and Max Value fields – – this reads the current values from the point in the simulation being displayed in the Viewer at the moment. Unselect Auto Update and set minimum to 0m/s 0m/s and maximum to 7m/s. 7m/s. 6. Click the Apply button to color the particles. 7. Check the Show Legend box Legend box then click Apply. 8. Click the Play button to view the distribution of velocity over time.

Step 3: Modifying Selections The instructions of how to create the mass flow sensor and grid bin group can be found in Part 1 (page ( page 18). 18). Repeat them and then modify the dimensions of mass flow sensor slightly. The queries should stay the same as previously. previously.

Modify a mass flow sensor 1. Click on the Selection tab. 2. From the Selection drop-down drop-down menu, menu, select select Mass Flow Sensor 01. 01. 3. Modify the properties properties of of the bin group group as follows follows then click click Apply:

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Step 4: Plotting the graphs New graphs need to be created for this configuration.

Plot a graph of mass flow rate on the bottom conveyor To plot a linear graph of mass flow rate of all particles changing over time on the bottom conveyor: 1. Click the Analyst button on the toolbar, then click the Create Graph button

.

2. In Line Graph tab, set the parameters parameters as follows:

3. In the X-axis X-axis tab, ensure that Time Range Range covers whole simulation simulation time. 4. Click the Y-axis tab. tab. Set the Primary Primary Attribute to Mass Flow Rate. 5. Click Create Create Graph at at the bottom bottom to plot plot the graph. 6. To save the image go to File>Print Image…

It can be observed from the graph that the f irst particles flow through the sensor after about 4 seconds of simulation.

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EDEM Tutorial: Rock Box To get more detailed plot: 7. In X-axis tab, set the Start time to about 4s. Click Create Graph to see the new plot. 8. In order to generate the graph graph of mass flow rate when when the system reaches steady state, set the Start time to about 8.5s. Click Create Graph button.

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Plot the graph of total particle mass in the rock box A rectangular bin bin group over over the rock box registers registers the change of of total mass of the particles there. To plot the increase in mass over time in the rock box: 1. In Line Graph tab, set the parameters parameters as follows:

2. In the X-axis X-axis tab, ensure that Time Range Range covers whole simulation simulation time. 3. Click the Y-axis tab. tab. Set the Primary Primary Attribute Attribute to Mass and Mass and the Component to Total. Total. 4. Click Create Create Graph at the bottom to plot the graph. 5. To save the image go to File>Print Image…

6.

Experiment with changing changing Start time in X-tab to different different values. values.

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Plot the pie chart of percentage of each particle type in the rock box The Rock_Box bin group can also be used to analyze the content of different particle types in the rock box. To create the pie chart of the distribution: 1. Choose a Pie Chart Chart tab and set the parameters parameters as follows:

2. In the Define Define Attribute tab, set the Attribute to Number of Particles and select Total as Component. 3. In the Settings tab, leave leave the checkbox checkbox Current Time Step checked. The number of particles in the time step in which you stopped the simulation will be shown. You can change the current time step in Viewer Controls, on the right hand side of the screen. 4. Click Create Graph button. The image image below was was taken in about about 9.6s time step. It can be seen that there is the biggest amount of particles of t ype 2. 5. Now change change the Attribute to Mass, leaving the Component set to Total as previously. 6. Click Create Create Graph button button to see a new pie chart for the same time step. 7. Notice that the distribution distribution of of mass is equal for all particles particles types. The previous previous graph showed the biggest number of particles of type 2 as t hese are the lightest – lightest – the mass is about twice smaller than the mass of t he particles of type 1 and 3.

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Tut3-Rock-box_v2.5

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