Defining the DEM Particle Phase Interactions

You define the behaviour of the solid particles when they collide with each other, or when they hit the wall or phase impermeable boundaries. You use the Hertz-Mindlin model to model the contact effects in these situations. To consider inter-molecular attraction forces between particle surfaces, such as van der Waal or cohesion forces, you select the Linear Cohesion model.

  1. To define the DEM particle phase interactions:
    1. Right-click the Continua > Physics 1 > Models > Multiphase Interaction > Phase Interactions node and select New > Particle > Particle.
    2. Rename the Phase Interaction 1 node to Particle-Particle.
    3. Double-click the Particle-Particle > Models node and select the following models, in order:
      Group Box Model
      DEM Contact Model Hertz Mindlin
      Optional Models Linear Cohesion
    4. In the Particle-Particle Model Selection dialog, deselect Rolling Resistance.
    5. Select the Particle-Particle > Models > Hertz Mindlin node and set the following properties:
      Property Value
      Static Friction Coefficient 0.6
      Normal Restitution Coefficient 0.1
      Tangential Restitution Coefficient 0.1
    6. Select the Models > Linear Cohesion > Work of Cohesion node and set Value to 1.0 N/m.
  2. Define the interaction between the particles and the wall:
    1. Right-click the Continua > Physics 1 > Models > Multiphase Interaction > Phase Interactions and select New > Particle > Wall.
    2. Rename the Phase Interaction 1 node to Particle-Wall.
    3. Double-click the Particle-Wall > Models node and from the DEM Contact Model group, select Hertz Mindlin. In the Enabled Models group box, deselect Rolling Resistance.
    4. Select the Particle-Wall > Models > Hertz Mindlin node and set the following properties:
      Property Value
      Static Friction Coefficient 0.15
      Normal Restitution Coefficient 0.1
      Tangential Restitution Coefficient 0.1
  3. Define the interaction between the particles and the flow boundaries that are impermeable to the particles.
    1. Copy and paste the Particle-Wall node onto the Phase Interactions node and rename the copy to Particle-Phase Impermeable.
    2. Select the Particle-Phase Impermeable > Models > DEM Phase Interaction node and set Second Phase to Phase Impermeable.
  4. Save the simulation.