Dispersed Multiphase (DMP)

The Dispersed Multiphase (DMP) model simulates dispersed phases in a Eulerian manner. The Dispersed Multiphase model combines aspects of both the Lagrangian Multiphase (LMP) model and the Eulerian Multiphase (EMP) models.

  • Like the EMP model, Dispersed Multiphase solves for the dispersed phases in a Eulerian manner.
  • When used in the default one-way coupled mode, Dispersed Multiphase does not calculate the flow in the background medium (that is, the Physics Continuum). This behavior is like the LMP model.

The main difference between DMP and EMP is that the Eulerian phases in the DMP model represent only the phases that are dispersed. The continuous background phase is solved with typical single-phase models.

By default, DMP is one-way coupled: the background flow can influence the dispersed phases (for example, through drag force and heat transfer) but not the reverse. The existence of the dispersed phases has no effect on the background phase. The only way in which the dispersed phases can influence the physics continuum is through impingement onto a liquid film. Two-way coupling is optional in a DMP simulation. When two-way coupling is activated, the dispersed phases can influence the physics continuum. Drag force and heat transfer contribute to all phases, and the volume of the dispersed phases is subtracted from the available volume for the background phase.

The DMP model and the VOF model can be activated in the same simulation. The DMP model uses the VOF mixture as its background flow, and has no knowledge of the individual phases. The DMP model treats the mixture as a single phase and uses only the properties of the mixture.

Advantages of Using the DMP Model

The DMP model is useful for airfoil icing applications, for which it is more appropriate than either the EMP model or the LMP model. Using the LMP model for these applications would be time-consuming due to the large number of parcels that are required. The DMP model can also be useful in soiling applications.

For an example of an airfoil icing simulation, see the Dispersed Multiphase: Airfoil Icing tutorial in the Tutorial Guide.

The EMP model does not support a coupled solution of background flow and energy, which is often required in these applications.

Disadvantages of Using the DMP Model

The DMP model cannot use many of the complex physics models that are available with the EMP model or the LMP model, such as turbulent dispersion. The DMP model cannot model evaporation or other interactions with the background fluid.

The DMP model does not model interactions between droplets of the dispersed phase, or complicated wall interactions (such as splashing). The LMP framework provides models for these effects.