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.
 GasLiquid or LiquidLiquid Flows
 GasSolid Flows
 LiquidSolid Flows
 Particle Flows/ThreePhase Flows
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, churn and annular which include both dispersed 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.  
EulerEuler 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. 

Algebraic Interfacial Area Density (AIAD) Model For flows that may include a transition between continuous stratified flows and dispersed flow regimes. In conjunction with a population balance model, it provides detailed size distributions of bubbles or droplets. 

Eulerian Model Accurately models multiple separate, yet interacting, phases including liquids, gases or solids in any combination. 

Mixture Model Simplifies the Eulerian model when the relaxation time of the dispersed phase is small 

EulerGranular Uses Eulerian approach to model dispersed particles in a continuous fluid. Uniformsized particle motion is modeled using averages, not individually. 

Population Balance Model For systems where particle size distributions change due to fluid behavior like droplet break up, nucleation, agglomeration. Typically used in conjunction with other models to account for particle distributions. 

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. 

EulerLagrange 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. 
Particleparticle interactions not important; dispersedphase volume is low (<10%)  Particleparticle interactions not important; dispersedphase volume is low (<10%)  
Dense Discrete Phase Model Extends the Discrete Phase Model to account for higher volumes of dispersed second phase. 
Particleparticle interactions not important; dispersedphase volume higher (<30%)  Particleparticle interactions not important; dispersedphase volume higher (<30%)  
Discrete Element Method Tracks individual interacting particles. Used for flows with a high volume fraction of particles, where particleparticle interaction is important. Interaction with the fluid flow may or may not be important.  Particleparticle interactions important  Particleparticle 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 steadystate 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 remeshing 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 indepth support on model selection and usage. 
Species Transport and FiniteRate 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 nonpremixed 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 fluidcarrying 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 
Multiphase Models  Particleladen 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 fluidsolid mixture that exhibits fluidlike properties.  
Cyclone separators, air classifiers, dust collectors, and dustladen environmental flows.  Transport of cement, grains, and metal powders.  Fluidized bed reactors and circulating fluidized beds used in chemical processes and coal combustion.  
EulerEuler 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. 

Algebraic Interfacial Area Density (AIAD) Model For flows that may include a transition between continuous stratified flows and dispersed flow regimes. In conjunction with a population balance mod el, it provides detailed size distributions of bubbles or droplets. 

Eulerian Model Accurately models multiple separate, yet interacting, phases including liquids, gases or solids in any combination. 
When phases mix and/or dispersedphase 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  
EulerGranular Uses Eulerian approach to model dispersed particles in a continuous fluid. Uniformsized particle motion is modeled using averages, not individually. 
Particleparticle interactions important  
Population Balance Model For systems where particle size distributions change due to fluid beahvior like droplet break up, nucleation, agglomeration. 

EulerLagrange 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. 
Particleparticle 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. 
Particleparticle 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 particleparticle interaction is important. Interaction with the fluid flow may or may not be important.  Particleparticle 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 steadystate 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 remeshing 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 indepth support on model selection and usage. 
Species Transport and FiniteRate 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 nonpremixed 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 fluidcarrying 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.  
EulerEuler 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. 

Algebraic Interfacial Area Density (AIAD) Model For flows that may include a transition between continuous stratified flows and dispersed flow regimes. In conjunction with a population balance mod el, it provides detailed size distributions of bubbles or droplets. 

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. 

EulerGranular Uses Eulerian approach to model dispersed particles in a continuous fluid. Uniformsized particle motion is modeled using averages, not individually. 
Particleparticle interactions important  
Population Balance Model For systems where particle size distributions change due to fluid beahvior like droplet break up, nucleation, agglomeration. 

EulerLagrange 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 particleparticle 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 steadystate 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 remeshing 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 indepth support on model selection and usage. 
Species Transport and FiniteRate 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 nonpremixed 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 fluidcarrying 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  ThreePhase 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, gasoilwater separator, twophase fluidized bed with solid catalysts.  
EulerEuler 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. Algebraic Interfacial Area Density (AIAD) Model may be especially well suited for liquidgasparticle flows. 

Algebraic Interfacial Area Density (AIAD) Model For flows that may include a transition between continuous stratified flows and dispersed flow regimes. In conjunction with a population balance mod el, it provides detailed size distributions of bubbles or droplets. 

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. 

EulerGranular Uses Eulerian approach to model dispersed particles in a continuous fluid. Uniformsized 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. 

EulerLagrange 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 particleparticle 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 steadystate 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 remeshing 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 indepth support on model selection and usage. 
Species Transport and FiniteRate 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 nonpremixed 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 fluidcarrying 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 