Limitations

Limitations of using Discrete Phase Model

Limitations of using Discrete Phase Model

The Discrete Phase Model (DPM) is a method that could simulate the motion of particles in the computational domain.

However, several limitations exist when using this model that must be paid attention to to avoid divergence or wrong results. Mentioned limitations are listed below:

  • As discussed previously in detail at the “DPM (Grid Size Dependency)” blog, the discrete phase is considered to dilute so that the particle-particle interactions are neglected. Subsequently, a high volume concentration of particles in the domain would have less solution accuracy. Going by a rule of thumb, the volume fraction of the discrete phase must be less than 10-12 % in each computational cell.

 

  • To avoid this limitation, users can use the Dense Discrete Phase Model (DDPM), in which the effects of friction and volume fraction are added. Also, Parcel-parcel contacts are defined in Discrete Element Models (DEM), so the parcels can be closely packed.
  • DPM can not effectively simulate the systems in which suspension or sedimentation occurs.

 

LimitationsLimitations

  • If particle rotation is enabled in DPM:discrete phase MR CFD           injection    MR CFD       physical models MR CFD          particle rotation

Limitations

Limitations

  • The rotation of particles is not affected by the particle-particle collision in a four-way interaction simulation.
  • If the particles are massless, the physical models’ Tab is unavailable.

MR CFD

  • By turning on the particle rotation option, the Magnus lift force effect will be considered:

Discrete Phase Model

  • The cloud model is not available when using unsteady particle tracking or High-Resolution Tracking.

MR CFD

Discrete Phase Model

  • If DPM and multiphase flow models are used simultaneously, the Shared Memory option is unavailable.

Discrete phase model   MR CFD  Parallel MR CFD MethodMR CFD Shared Memory

MR CFD

  • The eulerian wall film model is not compatible with particles, and an approaching particle to the film, will ignore it and reflect by the wall.

Setup MR CFD Models MR CFD  Eulerian Wall Film

MR CFD

  • By using multiple reference frames, the trajectory of particles is meaningless. Absolute velocity could be used instead of relative velocity to solve this problem. Following text command in the console would turn on the trajectory in absolute frame:

define/models/DPM/ options/track-in-absolute-frame

  • It should be noted that after entering the track-in-absolute-frame option, injection velocities will be calculated related to the absolute frame.
  • When the element number of the simulation is very large, the High-Resolution Tracking option must be enabled.

This Post Has 0 Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

Back To Top
Search

Refund Reason

Call On WhatsApp