Polyhedral Particles Model Reference
The Polyhedral Particles model allows you to use particles of any polyhedral shape rather than particles composed of combinations of spheres. The contact aspects of polyhedral DEM particles are based on energy-conserving contact interaction models [98].
| Provided By | ||
| Example Node Path | ||
| Requires | In
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In :
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| Properties | Moment of Inertia Scaling and Part. See Polyhedral Particle Model Properties. | |
| Specific Right-Click Actions | See Polyhedral Particle Model Right-Click Actions. | |
| Activates | Injector Inputs |
, Particle Orientation and Polyhedron Elongation Factor See Polyhedral Particles Injector Inputs. |
| Field Functions | Particle Diameter, Particle Projected Area, Particle Projected Length, Polyhedron Elongation Factor See Discrete Element Method Field Functions Reference. | |
The computational cost of this model is proportional to the number of non-coplanar faces representing the surface of the polyhedron. Before running a simulation, right-click the Polyhedral Particle model node and select Show Part to display the surface representation of the template polyhedron and check the number of faces.
Polyhedral Particle Model Properties
- Principal Moment of Inertia
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Read-only property reporting the principal moment of inertia of the particle, which is composed of user-defined shapes. This property is used when calculating the momentum balance (see Eqn. (2960)).
- Area
- Read-only property reporting the area of the particle.
- Volume
- Read-only property reporting the volume of the particle.
- Sphericity
- Read-only property reporting the sphericity of the particle. This property is used when calculating the Haider and Levenspiel drag coefficient (see Eqn. (2977)).
- Moment of Inertia Scaling
- Provides a scaling factor for each axis of the moment of inertia of the particle. This can be used to simulate effects such as uneven distribution of mass within the particle, or the dynamical response of a non-spherical particle. The scaling factor has an allowed range on each axis of 1E-2 to 1E5. The default value is [1.0, 1.0, 1.0].
- Part
- The part selected to serve as a template for the polyhedral particles, a geometry part created from a 3D-CAD model, or a simple shape part, or an imported mesh part.
- Compute Convex Hull
- Repaired and re-meshed surfaces of particles often fail to be convex, but some simulations require convex particles. If a selected particle has concavities, this property, when On, converts the particle into a convex particle using the Convex Hull algorithm. The number of faces for the original part and the convex hull and the message Convex hull operation is successful appear in the Output window after you select Update Properties, or after the simulation runs for one time-step. The new shape first appears when the particles are injected, not from the Show Part action. Off is the default.
- The images below show a particle before and after conversion to convex.
Polyhedral Particle Model Right-Click Actions
- Show Part
- Opens a geometry scene showing the template polyhedral part.
- Update Properties
- Calculates the area, volume, moment of inertia, and sphericity of the template polyhedral part.
Polyhedral Particles Injector Inputs
- Orientation Specification
- Sets the initial orientation of the particle as it is injected.
- Particle Diameter
- Specifies the particle diameter as that of a sphere of equal volume.
- Particle Orientation
- Sets the initial orientation of the particle as it is injected.
- Polyhedron Elongation Factor
- An ordered triple of multipliers defining stretch factors (>1) or shrink factors (<1) for the template polyhedron along each axis of the moment of inertia of the particle. As such, the injected Lagrangian phase can have different shapes and sizes of polyhedral particles of the same topology, based on the template described in the Part property of the Polyhedral Particle model.
The Polyhedral Particles model is incompatible with the Random Injector using the Maximum Packing option.
Compatibility with Other Models
The following models are incompatible with the Polyhedral Particles model. If any of them are selected when you select Polyhedral Particles, Simcenter STAR-CCM+ de-selects the incompatible models and posts the message Removing incompatable model(s) in [Phase Interaction].
- Artificial Viscosity
- Hertz Mindlin
- Linear Cohesion
- Linear Spring, with either Normal Spring Stiffness Method or Tangential Spring Stiffness Method set to Particle Material Based.
- Parallel Bond
- Rolling Resistance, using the Displacement Damping or Constant Torque method
- Walton Braun