Available multiphase solvers 1. InterFoam 1.1 Description: 1. Solver for 2 incompressible, isothermal immiscible fluids using a VOF (volume of fluid)
phase-fraction based interface capturing approach. 2. The momentum and other fluid properties are of the "mixture" and a single momentum equation is solved. 3. Turbulence modeling is generic, i.e. laminar, RAS or LES may be selected. . 1.2 Applications: simulation of a broken water dam. 1.3 Equations being solved:
In the following equations the subscripts 1 and v denotes liquid and vapor phase respectively
1. Continui ty equation equation
2. M omentum omentum Equation
F s = Surface Tension Force Surface tension,
= Curvature of the interface
3. Phase Phase Conti nu ity Equati on
The necessary compression of the surface is done by introducing an extra artificial compression term, Ur into into the phase continuity equation, given by-
1.4 Extensions: The following extensions solves same basic equations as interFoam, but the support some extra features.
Supports mesh motion and mesh topology changes including adaptive 1. interDyMFoam: re-meshing.
2. interMixingFoam: Solver for 3 incompressible fluids, two of which are miscible, using a
VOF method to capture the interface. 3. LTSInterFoam: Local time stepping (LTS, steady-state) solver for 2 incompressible, isothermal immiscible fluids, using a VOF phase fraction based interface capturing approach. Multiple reference frame solver. 4. MRFInterFoam: 1.5 Similar Solvers: 1.
compressibl eM ul tiph aseI nterF oam- It can solve for n compressible, immiscible fluids. It has an extension MRFMultiphaseInterFoam ( Multiple reference frame solver).
2. InterPhaseChangeFoam 2.1 Description: 1. Solver for 2 incompressible, isothermal immiscible fluids with phase-change (e.g. cavitation ). 2. It uses VOF phase-fraction based interface capturing approach. 3. The momentum and other fluid properties are of the “mixture” and a single momentum equation is solved. 4. The set of phase-change models provided are designed to simulate cavitation but other mechanisms of phase change are supported within this solver framework. 5. Turbulence modeling is generic, i.e. laminar, RAS or LES may be selected. 2.2 Applications: Simulation of phase change due to cavitation 2.3 Equations being solved:
In the following equations the subscripts 1 and v denotes liquid and vapor phase respectively. 1. Continui ty equation
̇
̇ ̇ ̇
Denotes condensation and denotes evaporation which are given by different mass transfer models being used for the simulation. OpenFOAM provides mass transfer due to cavitation. Three cavitation models are provided by default given by Kunz, Merkle and Schnerr-Sauer.
] [
2. M omentu m equation
Surface Tension Force =
3. Phase conti nu ity equation
̇ ̇
The necessary compression of the surface is done by introducing an extra artificial compression term, into the phase continuity equation, given by
3. CavitatingFoam 3.1 Description: 1. Transient cavitation based on the homogeneous equilibrium model from which the
compressibility of the liquid/vapor “mixture” is obtained. 2. Turbulence modeling is generic, i.e. laminar, RAS or LES may be selected. 3. It is mainly used for cavitation phenomena in a fuel nozzle of an IC engine. 4. It‟s based on homogeneous mixture model. 3.2 Applications: Simulation of cavitation. 3.3 Equations Being Solved:
In the following equations the subscripts 1 and v denotes liquid and vapor phase respectively
– ( ) ( )
1. Continui ty Equation
is the homogeneous mixture velocity U 2. M ass f racti on of vapor
Liquid density at saturation vapor pressure Vapor density at saturation vapor pressure
is the mixture density, given by
3. M omentum Equation
4. Bar otropi c Equ ation of state
5. Pressur e equati on
3.4 Extensions: The following extensions solves same basic equations as interFoam, but the support some extra features. 1.
Supports mesh motion and mesh topology changes including CavitatingDyMFoam- adaptive re-meshing.
4. CompressibleInterFoam 4.1 Description: 1. Solver for 2 compressible, non-isothermal immiscible fluids using a VOF (volume of
fluid) phase-fraction based interface capturing approach. 2. The momentum and other fluid properties are of the "mixture" and a single momentum equation is solved. 3. Turbulence modeling is generic, i.e. laminar, RAS or LES may be selected. 4. The solver „compressibleInterFoam‟ is based on the solver „interFoam‟ and extends it to account for fluid compressibility effects. 4.2 Application: Simulation of a broken dam considering the compressibility of the air. 4.3 Equations being solved:
In the following equations the subscripts 1 and v denotes liquid and vapor phase respectively 1. Continui ty equation
2. M omentum Equation
= Surface Tension Force
3. Energy Equation
4. Phase Conti nu ity Equation
ψ =
Compressibility of the medium C = Speed of the sound in the medium 4.4 Extensions: The following extensions solves same basic equations as interFoam, but the support some extra features. 1.
Supports mesh motion and mesh topology changes compressibl eI nterD yM F oam- including adaptive re-meshing.
4.5 Similar Solvers: 1.
compressibl eM ul tiph aseI nterF oam-
It can support more than 2 compressible,
immiscible fluids.
5. PotentialFreeSurfaceFoam 5.1 Description: 1. Incompressible Navier-Stokes solver with inclusion of a wave height field to enable
single phase free surface approximation. 2. Wave height field, zeta , used by pressure boundary conditions. 3. Turbulence modeling is generic, i.e. laminar, RAS or LES may be selected. 4. It‟s a transient solver. 5.2 Applications: Simulation of waves. 5.3 Equations being solved: 1. Continui ty equation:
2. M omentum equation:
6. SettlingFoam
6.1 Description: 1. Solver for 2 incompressible fluids for simulating the settlings of the dispersed phase. 2. The momentum and other fluid properties are of the "mixture" and a single momentum equation is solved. 3. Turbulence modeling is generic, i.e. laminar, RAS or LES may be selected.
6.2 Applications: Simulation of sludge treatment in a settling tank. 6.3 Equations being solved
In the following equations the subscripts c and d denotes the continuous and the dispersed phase respectively.
1. M ixtu re Continui ty equation:
is the mixture density given by-
is the velocity of center of mass of the mix ture given by-
2. Dri ft equation:
is the diffusion coefficient which is made equal to molecular and turbulent viscosity.
is the drift velocity of the dispersed phase.
is the diffusion velocity of the dispersed phase.
3. M ixtu re momentum equation:
is the interfacial momentum transfer terms, to couple the two phases together. are the viscous stress tensor and turbulent viscous stress tensor respectively.
7. TwoLiquidMixingFoam 7.1 Description: 1. 2. 3. 4.
Transient solver for mixing of 2 incompressible fluids. Turbulence modeling is generic, i.e. laminar, RAS or LES may be selected. Flow is density difference driven. It‟s an isothermal solver.
7.2 Applications: Simulation of lock exchange.
7.3 Equations Being Solved:
In the following equations the subscripts respectively
1
and
2
denotes primary and secondary phase
6. Continui ty Equation
U is the mixture velocity.
7. Alpha Di ff usivity Equation
D is the molecular diffusivity is the molecular diffusivity due to turbulence is the Schmidt number
8. M omentum Equation
8. TwoPhaseEulerFoam 8.1 Description: 1. Transient solver for a system of 2 compressible fluid phases with one phase dispersed
(e.g. gas bubbles in a liquid) including he at transfer. 2. From the version 2.1.x of OpenFOAM, the capability to manage compressible fluid has been added. 3. The Eulerian approach, considers a solid phase with fluid like behaviors without particle tracking. This reduces the numerical effort required with a large number of particles. In this approach, the equations for each phase is considered and solved one by one. 4. Turbulence modeling is generic, i.e. laminar, RAS or LES may be selected. 8.2 Applications: Simulation of bubble Column, Simulation of fluidized bed. 8.3 Equations being solved
In the following equations the subscripts 1 and 2 denotes phase 1 and 2 respectively. Let‟s say phase 1 is the solid phase and the phase 2 is the fluid phase. 1. Continui ty equations:
2. M omentu m equation s:
i = 1, 2
are the solid shear viscosity and fluid shear viscosity. The fluid phase is assumed to be a Newtonian fluid. I is the unit tensor of rank 2. is granular pressure is the nd solid bulk velocity. Since it is assumed that the 2 phase is fluid, hence these two terms nd will be zero in the 2 momentum equation. is the possible momentum interactions between the phases, given by-
3.
En ergy equation s:
()
i=1, 2
are the internal energy, kinetic energy, enthalpy, thermal diffusivity and heat transfer coefficient respectively. 8.4 Similar Solvers: 1. MultiPhaseEulerFoam: It can solve for more than 3 phases.
