Multiphase Flows Models and Capabilities

Whether designing a hypersonic transport free from ice buildup, developing a blood enzyme test, delivering and melting rare metallic powder compounds for additive manufacturing or formulating a filtration system to provide clean drinking water in a remote location, engineers must account for the interactions between liquids, solids and gases. Each of these varied multiphase challenges requires a different modeling approach. Review the chart below to find the ANSYS models and capabilities that can solve your multiphase simulation problem.

To learn more about the challenges of multiphase simulations and examples of how engineers have modeled these complex flows, check out our Multiphase Flows page.

Mulitphase Models Dispersed Bubbly Flow Dispersed Droplet Flow Mixed or Transitional Flow Separated Flow
  Flow of bubbles in a continuous liquid. Flow of liquid droplets in a gas or immiscible liquid. Flows like slug, churnand annular whichinclude bothdispersed and separated elements. Immiscible fluids separated by a clearly defined interface.
Absorbers, aeration, air lift pumps, cavitation, evaporators, flotation, and scrubbers. Spays, absorbers, atomizers, combustors, cryogenic pumping, dryers, evaporation, gas cooling, and scrubbers. Large bubble motion in pipes or tanks, slug catcher. Sloshing in fuel tanks and offshore separator devices, wave motion simulation, boiling, condensation, container filling, centrifuges.
Bubbles Droplets Glass Filling Slug Flow
Euler-Euler
Models droplets, bubbles or particles dispersed in a continuous fluid phase. The dispersed particles act as a continuum and are not tracked individually.
Volume of Fluid (VOF)
Predicts the interface shape between immiscible fluid phases.
Predicts detailed jet breakup (surface tension)
Eulerian Model
Accurately models multiple separate, yet interacting, phases including liquids, gases or solids in any combination.
Phases mix or dispersed-phase volume >10% Phases mix or dispersed-phase volume >10%
Immiscible Fluid Model
Extends the Eulerian model to directly predict the interface shape.
Mixture Model
Simplifies the Eulerian model when load of the dispersed phase is small.
Phases mix or dispersed-phase volume >10% Phases mix or dispersed-phase volume >10%
Euler-Granular
Uses Eulerian approach to model dispersed particles in a continuous fluid. Uniform-sized particle motion is modeled using averages, not individually.
Population Balance Model
For systems where particle size distributions change due to fluid beahvior like droplet break up, nucleation, agglomeration.
  VOF to DPM Model
Significantly reduces computational effort for accurate spray modeling. This hybrid model uses the volume of fluid method to directly track the interface instabilities and surface tension effects that give rise to ligament and droplet formation. Then, the faster, more computationally efficient Lagrangian framework takes over to track the droplets. DPM to VOF capability is also available to model the opposite process, for example impingment of spray onto a wall film.
 
Euler-Lagrange
Tracks the movement of individual droplets, bubbles or particles through continuous fluid phases to model the overall behavior. The particles typically occupy a small part of the total volume.
Discrete Phase Model
Particle interactions are neglected and the dispersed second phase occupies a low volume fraction (<10%). Population balance models are used to account for particle distributions.
Particle-particle interactions not important; dispersed-phase volume is low (<10%) Particle-particle interactions not important; dispersed-phase volume is low (<10%)
Dense Discrete Phase Model
Extends the Discrete Phase Model to account for higher volumes of dispersed second phase.
Particle-particle interactions not important; dispersed-phase volume higher (<30%) Particle-particle interactions not important; dispersed-phase volume higher (<30%)
Discrete Element Method Tracks individual interacting particles. Used for flows with a high volume fraction of particles, where particle-particle interaction is important. Interaction with the fluid flow may or may not be important. Particle-particle interactions important Particle-particle interactions important
Supporting Models and Capabilities
Phase Change
Wide range of capabilities to model a material's transition from one phase to another
- Boiling
- Solidification and melting
- Cavitation
- Evaporation and condensation
Parts in Motion
Flow around the moving parts such as rotating blades, impellers and moving walls can render the problem unsteady when viewed from a stationary frame. A moving reference frame simplifies the model by converting the flow around the moving part to a steady-state problem with respect to the moving frame.
Sliding and Dynamic Mesh
Speeds and simplifies simulations using moving reference frames by allowing you to move the boundaries of a cell zone relative to other boundaries of the zone, and to adjust the mesh accordingly.
Overset Mesh
Simplifies and speeds simulations that include structured mesh around individual parts and part swapping, as well as moving cell zones, without having to use re-meshing or smoothing. Use with VOF model.
Turbulence
A range of turbulence models is required to obtain accurate results for multiphase applications. Oversimplification can introduce large errors.
Over 35 turbluence models in 14 families cover the range of multiphase modeling challenges. ANSYS best practice guides and training materials provide in-depth support on model selection and usage.
Species Transport and Finite-Rate Chemistry
Models mixing and transport of chemical species by describing convection, diffusion, and reaction sources for each component species. Multiple simultaneous
chemical reactions can be modeled, with volumetric reactions occurring in the fluid phase and/or on wall or particle surfaces, and in the porous region.
 
Combustion
Models both premixed, partially premixed and non-premixed turbulent combustion, including the formation of NOx, SOx and soot.
 
Porous Media
Models the restriction in flows caused by packed beds, filter papers, perforated plates, flow distributors and tube banks.
 
Erosion
Models the removal of material from a wall surface due to micromechanical deformation or cracking of the wall's surface. In fluid-carrying equipment (such as gas and water turbines, pumps, heat exchangersand so on), surface erosion is caused in part by the impact on equipment
walls of solid particles entrained within a fluid flow.
 
Spray
Models flows out of injectors and nozels to predict droplet size and velocity distribution. Incorporates phenomina such as breakup, droplet collision and dynamic drag.
 
Polyhedral Unstructured Mesh Adaption (PUMA)
Capturing the fine details in free surface flows and combustion simulations requires an extremely fine polyhedral mesh. Patented, polyhedral unstructured mesh adaptation (PUMA) automatically refines the polyhedral mesh to resolve fine details, while leaving coarser mesh in place to deliver high accuracy - without the wait.
 
Customization
User Defined Functions allow you to customize and significantly
enhance capabilities to meet your specific simulation needs.
- Customize boundary conditions, material property definitions, reaction rates, transport equations and more.
- Enhance standard multiphase models
Learn more about simulating multiphase flows

Multiphase Models Particle-laden Flow Pneumatic Transport Fluidized Bed  
  Flow of discrete particles in a continuous gas. Dry bulk materials move through a pipe by air or gas pressure. Gas rising through a bed of particles forms a fluid-solid mixture that exhibits fluid-like properties.
Cyclone separators, air classifiers, dust collectors, and dust-laden environmental flows. Transport of cement, grains, and metal powders. Fluidized bed reactors and circulating fluidized beds used in chemical processes and coal combustion.
Cyclone Separator Pneumatic Transport Fluidized Bed
Euler-Euler
Models droplets, bubbles or particles dispersed in a continuous fluid phase. The dispersed particles act as a continuum and are not tracked individually.
Volume of Fluid (VOF)
Predicts the interface shape between immiscible fluid phases.
Eulerian Model
Accurately models multiple separate, yet interacting, phases including liquids, gases or solids in any combination.
When phases mix and/or dispersed-phase volume fractions exceed 10% Granular flows Granular flows
Immiscible Fluid Model
Extends the Eulerian model to directly predict the interface shape.
Mixture Model
Simplifies the Eulerian model when load of the dispersed phase is small.
When particle load and volume need to be accounted for but interactions can be ignored Homogenous flows
Euler-Granular
Uses Eulerian approach to model dispersed particles in a continuous fluid. Uniform-sized particle motion is modeled using averages, not individually.
Particle-particle interactions important
Population Balance Model
For systems where particle size distributions change due to fluid beahvior like droplet break up, nucleation, agglomeration.
Euler-Lagrange
Tracks the movement of individual droplets, bubbles or particles through continuous fluid phases to model the overall behavior. The particles typically occupy a small part of the total volume.
Discrete Phase Model
Particle interactions are neglected and the dispersed second phase occupies a low volume fraction (<10%). Population balance models are used to account for particle distributions.
Particle-particle interactions not important; particle volume is low (<10%)
Dense Discrete Phase Model
Extends the Discrete Phase Model to account for higher volumes of dispersed second phase.
Particle-particle interactions not important; particle volume higher (<30%)
Discrete Element Method Tracks indlvidual interacting particles. Used for flows with a high volume fraction of particles, where particle-particle interaction is important. Interaction with the fluid flow may or may not be important. Particle-particle interactions important
Supporting Models and Capabilities
Phase Change
Wide range of capabilities to model a material's transition from one phase to another
- Boiling
- Solidification and melting
- Cavitation
- Evaporation and condensation
Parts in Motion
Flow around the moving parts such as rotating blades, impellers and moving walls can render the problem unsteady when viewed from a stationary frame. A moving reference frame simplifies the model by converting the flow around the moving part to a steady-state problem with respect to the moving frame.
Sliding and Dynamic Mesh
Speeds and simplifies simulations using moving reference frames by allowing you to move the boundaries of a cell zone relative to other boundaries of the zone, and to adjust the mesh accordingly.
Overset Mesh
Simplifies and speeds simulations that include structured mesh around individual parts and part swapping, as well as moving cell zones, without having to use re-meshing or smoothing. Use with VOF model.
Turbulence
A range of turbulence models is required to obtain accurate results for multiphase applications. Oversimplification can introduce large errors.
Over 35 turbluence models in 14 families cover the range of multiphase modeling challenges. ANSYS best practice guides and training materials provide in-depth support on model selection and usage.
Species Transport and Finite-Rate Chemistry
Models mixing and transport of chemical species by describing convection, diffusion, and reaction sources for each component species. Multiple simultaneous
chemical reactions can be modeled, with volumetric reactions occurring in the fluid phase and/or on wall or particle surfaces, and in the porous region.
 
Combustion
Models both premixed, partially premixed and non-premixed turbulent combustion, including the formation of NOx, SOx and soot.
 
Porous Media
Models the restriction in flows caused by packed beds, filter papers, perforated plates, flow distributors and tube banks.
 
Erosion
Models the removal of material from a wall surface due to micromechanical deformation or cracking of the wall's surface. In fluid-carrying equipment (such as gas and water turbines, pumps, heat exchangersand so on), surface erosion is caused in part by the impact on equipment
walls of solid particles entrained within a fluid flow.
 
Spray
Models flows out of injectors and nozels to predict droplet size and velocity distribution. Incorporates phenomina such as breakup, droplet collision and dynamic drag.
 
Customization
User Defined Functions allow you to customize and significantly
enhance capabilities to meet your specific simulation needs.
- Customize boundary conditions, material property definitions, reaction rates, transport equations and more.
- Enhance standard multiphase models

Multiphase Models Slurry Flows Sedimentation    
  Movement of a liquid carrying dispersed solid particles. Suspended particles settle out from the fluid and come to rest against a barrier.
Slurry transport, hydrotransport and mineral processing. Mineral and waste processing.
Cement Pouring Sedimentation
Euler-Euler
Models droplets, bubbles or particles dispersed in a continuous fluid phase. The dispersed particles act as a continuum and are not tracked individually.
Volume of Fluid (VOF)
Predicts the interface shape between immiscible fluid phases.
Eulerian Model
Accurately models multiple separate, yet interacting, phases including liquids, gases or solids in any combination.
Immiscible Fluid Model
Extends the Eulerian model to directly predict the interface shape.
Mixture Model
Simplifies the Eulerian model when load of the dispersed phase is small.
Euler-Granular
Uses Eulerian approach to model dispersed particles in a continuous fluid. Uniform-sized particle motion is modeled using averages, not individually.
Particle-particle interactions important
Population Balance Model
For systems where particle size distributions change due to fluid beahvior like droplet break up, nucleation, agglomeration.
Euler-Lagrange
Tracks the movement of individual droplets, bubbles or particles through continuous fluid phases to model the overall behavior. The particles typically occupy a small part of the total volume.
Discrete Phase Model
Particle interactions are neglected and the dispersed second phase occupies a low volume fraction (<10%). Population balance models are used to account for particle distributions.
Dense Discrete Phase Model
Extends the Discrete Phase Model to account for higher volumes of dispersed second phase.
Discrete Element Method Tracks individual interacting particles. Used for flows with a high volume fraction of particles, where particle-particle interaction is important. Interaction with the fluid flow may or may not be important.
Supporting Models and Capabilities
Phase Change
Wide range of capabilities to model a material's transition from one phase to another
- Boiling
- Solidification and melting
- Cavitation
- Evaporation and condensation
Parts in Motion
Flow around the moving parts such as rotating blades, impellers and moving walls can render the problem unsteady when viewed from a stationary frame. A moving reference frame simplifies the model by converting the flow around the moving part to a steady-state problem with respect to the moving frame.
Sliding and Dynamic Mesh
Speeds and simplifies simulations using moving reference frames by allowing you to move the boundaries of a cell zone relative to other boundaries of the zone, and to adjust the mesh accordingly.
Overset Mesh
Simplifies and speeds simulations that include structured mesh around individual parts and part swapping, as well as moving cell zones, without having to use re-meshing or smoothing. Use with VOF model.
Turbulence
A range of turbulence models is required to obtain accurate results for multiphase applications. Oversimplification can introduce large errors.
Over 35 turbluence models in 14 families cover the range of multiphase modeling challenges. ANSYS best practice guides and training materials provide in-depth support on model selection and usage.
Species Transport and Finite-Rate Chemistry
Models mixing and transport of chemical species by describing convection, diffusion, and reaction sources for each component species. Multiple simultaneous
chemical reactions can be modeled, with volumetric reactions occurring in the fluid phase and/or on wall or particle surfaces, and in the porous region.
 
Combustion
Models both premixed, partially premixed and non-premixed turbulent combustion, including the formation of NOx, SOx and soot.
 
Porous Media
Models the restriction in flows caused by packed beds, filter papers, perforated plates, flow distributors and tube banks.
 
Erosion
Models the removal of material from a wall surface due to micromechanical deformation or cracking of the wall's surface. In fluid-carrying equipment (such as gas and water turbines, pumps, heat exchangersand so on), surface erosion is caused in part by the impact on equipment
walls of solid particles entrained within a fluid flow.
 
Spray
Models flows out of injectors and nozels to predict droplet size and velocity distribution. Incorporates phenomina such as breakup, droplet collision and dynamic drag.
 
Customization
User Defined Functions allow you to customize and significantly
enhance capabilities to meet your specific simulation needs.
- Customize boundary conditions, material property definitions, reaction rates, transport equations and more.
- Enhance standard multiphase models

Multiphase Models Particle Flows   Three-Phase Flows    
  Flow of interacting particulates where there is negligible interaction with surrounding gas or liquid.   Gas, liquid and solid in combination of any flow regimes.
Conveyors, hoppers, filling.   Deep well, evaporator, gas-oil-water separator, two-phase fluidized bed with solid catalysts.
Conveyor   Multiphase Flows Separator
Euler-Euler
Models droplets, bubbles or particles dispersed in a continuous fluid phase. The dispersed particles act as a continuum and are not tracked individually.
Volume of Fluid (VOF)
Predicts the interface shape between immiscible fluid phases.
  Choose the model that is most appropriate for the aspects of the flow that are of most interest. Accuracy will not be as high as for flows that involve just one flow regime, since the model you use will be valid for only part of the flow you are modeling. User- defined functions are available to customize and extend capabilities.
Eulerian Model
Accurately models multiple separate, yet interacting, phases including liquids, gases or solids in any combination.
Immiscible Fluid Model
Extends the Eulerian model to directly predict the interface shape.
 
Mixture Model
Simplifies the Eulerian model when load of the dispersed phase is small.
Euler-Granular
Uses Eulerian approach to model dispersed particles in a continuous fluid. Uniform-sized particle motion is modeled using averages, not individually.
Population Balance Model
For systems where particle size distributions change due to fluid beahvior like droplet break up, nucleation, agglomeration.
Euler-Lagrange
Tracks the movement of individual droplets, bubbles or particles through continuous fluid phases to model the overall behavior. The particles typically occupy a small part of the total volume.
Discrete Phase Model
Particle interactions are neglected and the dispersed second phase occupies a low volume fraction (<10%). Population balance models are used to account for particle distributions.
Dense Discrete Phase Model
Extends the Discrete Phase Model to account for higher volumes of dispersed second phase.
Discrete Element Method Tracks individual interacting particles. Used for flows with a high volume fraction of particles, where particle-particle interaction is important. Interaction with the fluid flow may or may not be important.
Supporting Models and Capabilities
Phase Change
Wide range of capabilities to model a material's transition from one phase to another
- Boiling
- Solidification and melting
- Cavitation
- Evaporation and condensation
Parts in Motion
Flow around the moving parts such as rotating blades, impellers and moving walls can render the problem unsteady when viewed from a stationary frame. A moving reference frame simplifies the model by converting the flow around the moving part to a steady-state problem with respect to the moving frame.
Sliding and Dynamic Mesh
Speeds and simplifies simulations using moving reference frames by allowing you to move the boundaries of a cell zone relative to other boundaries of the zone, and to adjust the mesh accordingly.
Overset Mesh
Simplifies and speeds simulations that include structured mesh around individual parts and part swapping, as well as moving cell zones, without having to use re-meshing or smoothing. Use with VOF model.
Turbulence
A range of turbulence models is required to obtain accurate results for multiphase applications. Oversimplification can introduce large errors.
Over 35 turbluence models in 14 families cover the range of multiphase modeling challenges. ANSYS best practice guides and training materials provide in-depth support on model selection and usage.
Species Transport and Finite-Rate Chemistry
Models mixing and transport of chemical species by describing convection, diffusion, and reaction sources for each component species. Multiple simultaneous
chemical reactions can be modeled, with volumetric reactions occurring in the fluid phase and/or on wall or particle surfaces, and in the porous region.
 
Combustion
Models both premixed, partially premixed and non-premixed turbulent combustion, including the formation of NOx, SOx and soot.
 
Porous Media
Models the restriction in flows caused by packed beds, filter papers, perforated plates, flow distributors and tube banks.
 
Erosion
Models the removal of material from a wall surface due to micromechanical deformation or cracking of the wall's surface. In fluid-carrying equipment (such as gas and water turbines, pumps, heat exchangersand so on), surface erosion is caused in part by the impact on equipment
walls of solid particles entrained within a fluid flow.
 
Spray
Models flows out of injectors and nozels to predict droplet size and velocity distribution. Incorporates phenomina such as breakup, droplet collision and dynamic drag.
 
Customization
User Defined Functions allow you to customize and significantly
enhance capabilities to meet your specific simulation needs.
- Customize boundary conditions, material property definitions, reaction rates, transport equations and more.
- Enhance standard multiphase models