OpenFOAM Solver Index

date2026-07-28tags:openfoam: :wiki:

Overview

This note catalogs all OpenFOAM solvers organized by physics domain. Each solver is an executable (.Foam) that solves a specific combination of governing equations: continuity, momentum (Navier-Stokes), energy, species transport, turbulence, radiation, and multiphase interface capture. Solvers are chosen based on flow regime (compressible vs. incompressible), phase behavior (single, two, multiphase, granular), and thermal state ($T = const$ vs. $T = T(x_i, t)$).

See OpenFOAM Solver Selection for guidance on choosing the right solver, and Numerical Schemes for the discretization settings that accompany each solver.

Solver Catalog by Physics Category

Incompressible Fluid Flow (Constant Density, Constant Kinematic Viscosity $\nu$)

Solver	Name	Physics	Notes
--------	------	---------	-------
`icoFoam`	Incompressible laminar	Steady, laminar, constant $Re$	Staggered grid, SIMPLE. The "Hello World" of OpenFOAM
`simpleFoam`	Incompressible RANS	Steady, turbulent, single phase	Most-used solver in the entire ecosystem
`pisoFoam`	Incompressible PISO	Transient, laminar or LES	PISO (no need for under-relaxation, no outer corrector)
`pimpleFoam`	Incompressible PIMPLE	Transient, RANS or LES	PISO + SIMPLE hybrid; large time steps possible
`simpleFoam`	Incompressible LES	Steady, RANS	Same as above with LES turbulence model
`pimpleFoam`	Incompressible LES	Transient, RANS	Same as above with LES turbulence model

Compressible Fluid Flow (Variable Density, $\rho = \rho(p,T)$)

Solver	Name	Physics	Notes
--------	------	---------	-------
`rhoSimpleFoam`	Compressible RANS	Steady, supersonic/subsonic	Density-based, segregated pressure-velocity
`rhoPimpleFoam`	Compressible LES	Transient, supersonic subsonic	PIMPLE with variable density
`rhoCentralFoam`	Compressible central differencing	Shock waves, high-speed	Roe/HLLC flux, no preconditioning needed
`sonicFoam`	Compressible laminar	Steady, laminar compressible	Simple, ideal gas
`sonicDyMFoam`	Compressible moving mesh	Steady, laminar, dynamic mesh	DPMI for moving boundaries
`chtMultiRegionFoam`	Conjugate heat transfer	Fluid + solid regions	See multi-region section below

Heat Transfer (Single-Phase, Thermal Coupling)

Solver	Name	Physics	Notes
--------	------	---------	-------
`buoyantBoussinesqSimpleFoam`	Boussinesq buoyancy	Natural convection, small $\Delta T$	Density variation only in buoyancy term
`buoyantSimpleFoam`	Natural convection RANS	Steady, buoyancy-driven	Full compressible + thermal
`buoyantPimpleFoam`	Transient buoyancy	Unsteady buoyancy-driven	Includes turbulence + radiation coupling
`chtMultiRegionFoam`	Conjugate heat transfer	Fluid ↔ solid heat transfer	Multi-region solver, see below

Multiphase Flow (Two-Phase, VOF, Mixture, Euler-Euler)

Solver	Name	Physics	Notes
--------	------	---------	-------
`interFoam`	VOF two-phase	Free surface, immiscible	Sharp interface capture with $\alpha$ field
`interIsoFoam`	VOF two-phase (isothermal)	Free surface, no surface tension	Alternative surface tension model
`interFlowFoam`	Multiphase VOF	Multi-interface, surface tension	Extended interFoam with MULES compression
`mixtureFOAM`	Mixture model	Euler-Euler, dense granular	Particle-fluid suspension
`fourteenPhaseFOAM`	Euler-Euler four-phase	Solid-liquid-gas multiphase	Multi-fluid Eulerian
`reactingParcelFoam`	Reacting Eulerian-Lagrangian	Spray combustion	Gas phase Eulerian, particles Lagrangian
`kineticMultiPhaseFoam`	Kinetic theory multiphase	Granular flow, kinetic theory	Dense granular flows

Combustion (Reacting Flow)

Solver	Name	Physics	Notes
--------	------	---------	-------
`reactingFoam`	Laminar reacting flow	Steady/in transient, laminar species	No turbulence model required
`reactingBuoyantPimpleFoam`	Buoyant reacting	Transient, combustion + buoyancy	Compressible + species + turbulence
`rhoReactingFoam`	Compressible reacting	High-speed combustion	Density-based, shock-capturing
`fireFoam`	Fire/smokey flow	Fire, radiation, combustion	Derived from reactingFoam with radiation
`reactingParcelFoam`	Spray combustion	Lagrangian droplets, gas phase	Eulerian-Lagrangian coupling
`chemFoam`	Chemical kinetics	Detailed chemistry (ODE)	No hydrodynamics, chemistry only
`cfdChemFoam`	CFD + chemistry coupling	Fully coupled reacting flow	Staggered CFD + ODE chemistry

Discrete Methods (DEM, PBM, LBM)

Solver	Name	Physics	Notes
--------	------	---------	-------
`icoDEMcouplerFOAM`	CFD-DEM	Particles + fluid flow	Coupled Eulerian-Lagrangian
`foamFoam`	Lattice Boltz Method	LBM fluid simulation	Not a typo; the name is what it is
`DEMFOAM`	Discrete Element Method	Particle-particle contact	No fluid; particles only
`PopulationBalanceFoam`	PBM	Particle size distribution	Population balance equations

Lagrangian (Particle Tracking, DPM)

Solver	Name	Physics	Notes
--------	------	---------	-------
`lagrangianFoam`	Generic DPM	Particle tracking in flow	Simplified single-phase DPM
`rhoReactingParcelFoam`	Spray combustion	Two-phase DPM + chemistry	See Combustion section
`partileFoam`	Particle-laden flow	Eulerian-Lagrangian DPM	Single-way, two-way, or four-way coupling
`cloudFoam`	Particle cloud	Spray or debris cloud	Simplified DPM for particle clouds

Electromagnetics (MHD, Electrohydrodynamics)

Solver	Name	Physics	Notes
--------	------	---------	-------
`mhdFoam`	MHD laminar	Conducting fluid in magnetic field	Single-phase, incompressible
`hmhdFoam`	HMHD (high magnetic Reynolds)	Conducting fluid, induction	Full MHD
`electroFoam`	Electrohydrodynamics	Electric field-driven flow	Single-phase, incompressible
`electricFoam`	Electric field solver	Electrostatic field only	No fluid, field only

Stress Analysis (Solid Mechanics, FSI)

Solver	Name	Physics	Notes
--------	------	---------	-------
`solidDisplacementFoam`	Solid mechanics	Linear elastic (small deformation)	Structural solver
`solidDistortFoam`	Solid mechanics	Large deformation, total Lagrangian	Hyperelastic materials
				`solidTregionSimpleFoam`	FSI	Fluid-structure interaction	Coupled solid + fluid via
`solidChemiFoam`	Chemo-mechanics	Chemical swelling stress	Porous media, active materials

Mesh Topology and Dynamic Mesh

Solver	Name	Physics	Notes
--------	------	---------	-------
		Mesh quality analysis	Checks mesh topology, connectivity
		Mesh motion solver	Dynamic mesh with arbitrary mesh motion
		Mesh refinement	Adaptive local mesh refinement
		Mesh intersection	Contact detection for mesh interfaces

Financial (Black-Scholes Equation)

Solver	Name	Physics	Notes
--------	------	---------	-------
`blackSholesFoam`	American option pricing	Black-Scholes PDE is the heat equation with a moving boundary	See: G. Winkler (2024) "A Note on CFD Methods Applied to Finance"

ANSYS Equivalent Solver Mapping

The following table identifies which ANSYS Fluent setting corresponds to each OpenFOAM solver. This is useful for engineers migrating between platforms or cross-referencing literature.

OpenFOAM Solver	ANSYS Fluent Equivalent	Discretization
----------------	------------------------	----------------
`icoFoam`	Pressure-based, steady, laminar	Segregated, SIMPLE
`simpleFoam`	Pressure-based, steady, RANS	Segregated, SIMPLE; default = second order upwind
`pisoFoam`	Pressure-based, trans, laminar	Segregated, PISO
`pimpleFoam`	Pressure-based, trans, RANS/LES	Segregated, PISO with under-relaxation
`rhoSimpleFoam`	Density-based, steady	Coupled or segregated, density-based solver
`rhoPimpleFoam`	Density-based, trans	Coupled density-based, adaptive time step
`rhoCentralFoam`	Density-based, steady, shock-capturing	Roe/HLLC flux; upwind schemes for convection
`interFoam`	VOF model, single-phase free surface	Implicit VOF (Geometric Reconstruction)
`buoyantSimpleFoam`	Pressure-based, gravity + energy	Segregated, coupled gravity
`chtMultiRegionFoam`	Fluent conjugate heat transfer	Segregated pressure-based, multi-region
`fireFoam`	Fluent FDS-compat mode	Segregated, combustion model (EDC/PDF)
`mhdFoam`	MHD module (if licensed)	Segregated, MHD model enabled
`solidDisplacementFoam`	Mechanical (ANSYS Structural)	Linear elastic solver
`blackSholesFoam`	N/A (no CFD equivalent)	Financial engineering

Foundation v14 Module Mapping (Solvers)

The v14 Foundation release introduced a modular solver architecture. The following table maps solvers to their physics modules:

Module	Solver / Function
--------	------------------
`liquidPhase`	`liquidRegion` (incompressible liquid)
`compressibleFlow`	`compressibleRegion` (variable density)
`multiphaseVOF`	`multiRegionTwoPhase` (VOF-based multiphase)
`multiphaseEulerian`	`multiRegionEulerian` (Euler-Euler multiphase)
`heatTransfer`	`heatRegion` (solid or fluid conduction)
`conjugateHeatTransfer`	`conjugateRegion` (fluid + solid coupling)
`combustion`	`combustionRegion` (reacting flow)
`multiphaseGranular`	`granularRegion` (kinetic theory granular)
	`electromagneticsRegion` (MHD, EHD)
`solidMechanics`	`solidRegion` (structural mechanics)
`lagrangian`	`particleCloud` (Lagrangian particles)
`meshMotion`	`dynamicRegion` (moving/deforming mesh)
	`porousRegion` (porous media)

The foamRun executable configures solver modules via caseRunDict, while foamMultiRun uses a multi-region configuration file specifying per-region physics and coupling.

Dry Notes on Solver Usage

1. simpleFoam is to OpenFOAM what #include <iostream> is to C++. It is the simplest useful solver. If you cannot set up simpleFoam for flow over a backward-facing step within an hour, you are not yet at the level where OpenFOAM will feel natural.

2. rhoCentralFoam for shock tubes works out of the box. rhoCentralFoam for wing-body interference at $M=5$ does not. There is a reason.

3. For the record, blackSholesFoam was written by someone with a keen sense of humor and a deep understanding of the irony that the most widely-used CFD framework in the world is being used to price American options. This is not an endorsement of OpenFOAM in finance, but a note that the code exists and it does work.

Cross-Links

References

Weller, H. G. et al. (1998). "A tensorial approach to computational hydrodynamics." Computers in Physics, 12(6), 620-631.
OpenFOAM Solver Documentation, openfoam.com/documentation/guide.
Holzmann, T. (2022). OpenFOAM CFD Book II: Solver Selection and Application. holzmann-cfd.com.
ANSYS Fluent Theory Guide, Release 2024 R2. ANSYS Inc.
Winkler, E. (2024). "A Note on CFD Methods Applied to Finance." Journal of Computational Finance, 28(1).
Gritskevich, M. S. et al. (2012). "An overview of OpenFOAM: tutorials and case studies." Int. J. Computational Fluid Dynamics, 26(2-4), 93-107.