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Models

Where it is

Setup tree: Models

Controls

Analysis

Analysis type

Control: choice (ComboRow)
Default: Incompressible
Bound to: CaseState.analysisType
Options: Incompressible, Compressible, Convective Heat Transfer, Conjugate Heat Transfer, Multiphase (VoF), Multiphase (Euler-Euler), Particles (Lagrangian), Combustion / Reacting, Atmospheric & Wind, Marine & Waves, Scalar transport, Cavitation, Supersonic / shock, Solid conduction, Compressible multiphase, Miscible mixing, Sediment / drift flux, Shallow water, Free surface (potential), Premixed combustion, Spray, Solid stress, Electrostatics, Magnetostatics, Magnetohydrodynamics, Rotating frame (SRF), Molecular / rarefied
Writes: controlDict/application

The in-app guidance depends on the case:

Mach < 0.3, density variation negligible.
Particles rather than fields. No velocity, no pressure, no turbulence model - the Molecular step replaces Materials, Initial conditions, Boundary conditions and Numerics.
See the Create Simulation dialog for the full description.

Time dependency

Control: choice (ComboRow)
Default: Steady-state
Bound to: CaseState.timeDependency
Options: Transient, Steady-state (from either branch of CaseState.transientOnly``)
Writes: fvSchemes/ddtSchemes

This analysis has no steady form - the solver integrates in time.

Algorithm

Control: choice (ComboRow)
Default: SIMPLE
Bound to: CaseState.algorithm
Options: SIMPLE, SIMPLEC, PIMPLE, PISO (from either branch of CaseState.steady``)
Writes: fvSolution/…

Turbulence

Model

Control: choice (ComboRow)
Default: k-omega SST
Bound to: CaseState.turbulenceModel
Options: Laminar, k-epsilon, realizable k-epsilon, RNG k-epsilon, k-omega, k-omega SST, k-omega SST LM, GEKO, EBRSM, Spalart-Allmaras, LRR (RSM), SSG (RSM), LES WALE, LES Smagorinsky, SA-DDES, SST-IDDES
Writes: turbulenceProperties/RAS/model

Wall treatment

Control: choice (ComboRow)
Default: Wall functions
Bound to: CaseState.wallTreatment
Options: Wall functions, Resolved (low-Re), Automatic blending

Selects a coherent set across nut, k, omega and alphat.

Physics

Energy equation

Control: on/off (ToggleRow)
Default: false
Bound to: CaseState.energyEnabled

Gravity / buoyancy

Control: on/off (ToggleRow)
Default: false
Bound to: CaseState.gravityEnabled

Surface tension

Control: value (ValueField)
Unit: N/m
Default: 0.07
Bound to: CaseState.surfaceTension
Writes: transportProperties/sigma
Shown when: CaseState.analysisFamily === "fluids" && String(CaseState.solver).indexOf("inter") >= 0

Between the two phases. 0.07 N/m is water against air at 20 C.

Problems reported against this step

The application checks these before a run and reports them in the Problems tab against this step.

Severity	Message
error	… has no steady form. … integrates in time; set Time dependency to Transient.
info	The ignition kernel (… mm) is narrower than two mesh cells, so it is written … mm wide: the flame-wrinkling transport equation diverges on a spark that fits inside one cell. Refine the mesh if the kernel size matters.
error	A two-phase case needs gravity. Without it there is nothing to separate the phases and the interface will not settle.
error	… has no turbulence model, so it will not read k, omega or nut. Set the turbulence model to Laminar, or choose a solver that has one.
error	… has no steady form. Set the time dependency to Transient.
error	… has no transient form. Set the time dependency to Steady-state.
warn	… needs …, which this app does not write. Add it to the case directory before running.
warn	… cannot be set up completely by this build: it needs …. The case will be written and the mesh will build, but the solver stops at start-up.
warn	This build of the equilibrium stress solver does not converge - the correction it computes points away from equilibrium, and the run ends on a floating-point trap whatever the acceleration factor. Displacement solves the same steady problem on this case, because the time scheme here is already steady, and it converges.
error	… is not part of the … tier. The case is safe and nothing has been lost - choosing another analysis type, or upgrading, will let it run.
warn	Gravity is off for a buoyancy-sensitive analysis type.

… marks a value the application computes at run time, so the source carries no fixed text for it.