7.38. Solution Options
This section is referenced in the following other sections
7.38.1. Solution Options
- Scope
Aria Region
- Summary
Specify information regarding the governing equations to be solved.
begin Solution Options OptionsName Apply Flux Limiter Stabilization Check Matrix For Discrete Maximum Principle Face Stabilization Multiplier Multiplier Force Non Tale Free Stream Reynolds Number input_Re Ignore Coordinate Displacements Maximum Temperature Allowed From Temperature Extraction MaxTemp Maximum Wall Time WallTime Hours Minimum Temperature Allowed From Temperature Extraction MinTemp Omit Enthalpy Adjustment After Temperature Clipping Omit Finite Difference Sensitivities For Cantera Properties Use Inverse Density Continuity Scaling begin Cvfem Algorithm Specification PStabName end begin Edc Model Specification EdcSpecName end begin Hdiff Model Specification HdiffOptionsName end begin Porous Flow Options blockName end begin Species Options blockName end begin Turbulence Model Specification TurbSpecName end end Solution Options OptionsName
7.38.1.1. Line Commands
Apply Flux Limiter Stabilization
- Syntax
Apply Flux Limiter Stabilization
- Summary
Enables flux limiter stabilization for diffusion.
- Description
This activates flux limiter stabilization for diffusion terms to prevent non-physical temperatures on meshes that don’t satisfy the requirements for a discrete maximum principle, or for anisotropic material properties.
Check Matrix For Discrete Maximum Principle
- Syntax
Check Matrix For Discrete Maximum Principle
- Summary
Examine rows of the system matrix before boundary conditions are applied and check if the diagonal entries are non-negative, the off-diagonal entries are non-positive, the row-sum is non-negative. If these conditions fail, it is possible the solution will contain non-physical values, and the discrete maximum principle is not satisfied by the matrix. If any of these conditions fail, a warning is printed to the log file. More output can be obtained with turning on debug logging.
Face Stabilization Multiplier
- Syntax
Face Stabilization Multiplier Multiplier
- Summary
Multiplier for face stabilization term.
- Description
This value specifies the multiplier applied to the stabilization terms activated by the GRAD_JUMP_PENALTY or DMP stabilization terms on the specified equation.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
Multiplier |
real |
1.0 |
Force Non Tale
- Syntax
Force Non Tale
- Summary
Enable (true) to force simulation not to use TALE.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{false | no | off | on | true | yes} |
FALSE |
Free Stream Reynolds Number
- Syntax
Free Stream Reynolds Number input_Re
- Summary
Input Reynolds number is used for solving nondimensional viscous problems using the GasDyn equations.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
input_Re |
real |
– |
Ignore Coordinate Displacements
- Syntax
Ignore Coordinate Displacements
- Summary
Enable (true) or disable (false) displacing the physical coordinates by either MESH_DISPLACEMENTS or SOLID_DISPLACEMENTS. By default, this is false, and physical_coordinates are displaced. However, this can be disabled by setting this to true, and physical_coordinates will be equal to model_coordinates.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{false | no | off | on | true | yes} |
FALSE |
Maximum Temperature Allowed From Temperature Extraction
- Syntax
Maximum Temperature Allowed From Temperature Extraction MaxTemp
- Summary
Specify a maximum cutoff temperature for extraction from enthalpy and composition
- Description
This option specifies the maximum temperature to be allowed to be extracted from enthalpy, given the mixture composition. If a temperature is computed that is greater than this value, the temperature is reset to equal the maximum allowed value.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
MaxTemp |
real |
2400.0 K |
Maximum Wall Time
- Syntax
Maximum Wall Time WallTime Hours
- Summary
Specify a maximum wall time to let the simulation end gracefully and output before slurm kills it.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
WallTime |
real |
Infinite |
Minimum Temperature Allowed From Temperature Extraction
- Syntax
Minimum Temperature Allowed From Temperature Extraction MinTemp
- Summary
Specify a minimum cutoff temperature for extraction from enthalpy and composition
- Description
This option specifies the minimum temperature to be allowed to be extracted from enthalpy, given the mixture composition. If a temperature is computed that is less than this value, the temperature is reset to equal the minimum allowed value.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
MinTemp |
real |
250.0 K |
Omit Enthalpy Adjustment After Temperature Clipping
- Syntax
Omit Enthalpy Adjustment After Temperature Clipping
- Summary
Do not adjust enthalpy to be consistent with clipped temperatures
- Description
When temperature extraction fails to produce a viable result, the temperature will usually be clipped at either the upper or lower limit temperature. By default, the enthalpy will then be adjusted up or down to match the clipped temperature so that the thermochemical state is internally consistent. This omits the enthalpy adjustment, leaving clipped nodes in an inconsistent state.
Omit Finite Difference Sensitivities For Cantera Properties
- Syntax
Omit Finite Difference Sensitivities For Cantera Properties
- Summary
Do not populate any Cantera property sensitivities via finite difference
Use Inverse Density Continuity Scaling
- Syntax
Use Inverse Density Continuity Scaling
- Summary
Enable (true) or disable (false) the inverse element scaling of the continuity equation.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{false | no | off | on | true | yes} |
TRUE |
7.38.1.2. Cvfem Algorithm Specification
- Summary
Specify CVFEM algorithmic modeling options.
begin Cvfem Algorithm Specification PStabName Activate Acoustic Compressibility Algorithm Activate Ausm Plus Scheme Activate Edge Based Diffusion Operator [ With ] Activate Edge Based Fourth Order Advection Activate Kexact Muscl Scheme For Equation EquationString [ SpeciesName | MaterialPhaseName] [ Using K kappa ] Activate Mixture Fraction Clipping Utility At Activate Muscl Scheme For Equation EquationString [ SpeciesName | MaterialPhaseName] Activate Pressure Projection Algorithm Activate Projected Stress Stabilization Activate Scv Nodal Gradient Activate Shakib Scaling Activate Vrtm In Mass Flux Vector Ausm Alpha alpha Ausm Beta beta Clip Cvfem Level Set Dof First Order Upwind Factor RealValue For Equation EquationString [ SpeciesName | MaterialPhaseName] Flux Scheme Freeze Muscl Limiter At Global Step freezeStep Hybrid Upwind Factor RealValue For Equation EquationString [ SpeciesName | MaterialPhaseName] Interpolate Density And Velocity Separately In Mass Flux Vector Lag Nodal Pressure Gradient In Mass Flux Vector Expression Lag Nodal Tau In Mass Flux Vector Expression Muscl Limiter For Equation EquationString [ SpeciesName | MaterialPhaseName] Omit Diffusion Term From Sucv Tau Omit Disting Bc Ip Sensitivities Omit Dt Term From Sucv Tau Pressure Stabilization Characteristic Length CharLength Pressure Stabilization Order Pressure Stabilization Parameter Scaling TauScaling Pressure Stabilization Scaling [ With Value ConstantTau ] Roe Entropy Fix C epsc Roe Entropy Fix U epsu Upwind Method For Equation EquationString [ SpeciesName | MaterialPhaseName] Use Approximate Roe Sensitivities Use Opposing Subface In Open Mass Flux Use Specified Pressure In Open Mass Flux end Cvfem Algorithm Specification PStabName
7.38.1.2.1. Line Commands
Activate Acoustic Compressibility Algorithm
- Syntax
Activate Acoustic Compressibility Algorithm
- Summary
Variable thermodynamic pressure to allow for closed system pressurization
Activate Ausm Plus Scheme
- Syntax
Activate Ausm Plus Scheme
- Summary
Activate AUSM plus with standard values for alpha and beta
- Description
Activate AUSM plus scheme.
Activate Edge Based Diffusion Operator
- Syntax
Activate Edge Based Diffusion Operator [ With ]
- Summary
Activate edge-based scheme for diffusion operator.
- Description
Only implemented now for tke and sdr - interior only
Activate Edge Based Fourth Order Advection
- Syntax
Activate Edge Based Fourth Order Advection
- Summary
Activate edge-based advection for fourth order LES scheme
- Description
Activate edge-based advection for fourth order LES scheme
Activate Kexact Muscl Scheme For Equation
- Syntax
Activate Kexact Muscl Scheme For Equation EquationString [ SpeciesName | MaterialPhaseName] [ Using K kappa ]
- Summary
Use kexact MUSCL variable extrapolation for the specified equation
- Description
Use kexact MUSCL variable extrapolation for the specified equation. The projected gradients for the necessary variables must be computed using a cvfem_lumped_muscl_projection equation.
Parameter |
Value |
Default |
|---|---|---|
EquationString |
string |
– |
{of | species} |
– |
|
SpeciesName |
string |
– |
{in | material_phase} |
– |
|
MaterialPhaseName |
string |
– |
Activate Mixture Fraction Clipping Utility At
- Syntax
Activate Mixture Fraction Clipping Utility At
- Summary
Activate clipping utility for mixture fraction
- Description
Sometimes it helps to clip the mixture fraction. This is a utility that provides this support.
Parameter |
Value |
Default |
|---|---|---|
{begin_nonlinear_solve | end_nonlinear_solve | manually_run | post_iterate | post_linear_solve | post_nonlinear_solve | pre_iterate | pre_linear_solve | pre_nonlinear_solve | run_initially | run_once | run_post_linear_system_initialization} |
– |
Activate Muscl Scheme For Equation
- Syntax
Activate Muscl Scheme For Equation EquationString [ SpeciesName | MaterialPhaseName]
- Summary
Use MUSCL variable extrapolation for the specified equation
- Description
Use MUSCL variable extrapolation for the specified equation. The projected gradients for the necessary variables must be computed using a cvfem_lumped_muscl_projection equation.
Parameter |
Value |
Default |
|---|---|---|
EquationString |
string |
– |
{of | species} |
– |
|
SpeciesName |
string |
– |
{in | material_phase} |
– |
|
MaterialPhaseName |
string |
– |
Activate Pressure Projection Algorithm
- Syntax
Activate Pressure Projection Algorithm
- Summary
Activate PP alg.
- Description
Rather than fully coupling uvwp, activate a pressure projection algorithm. This will require creating two EQ systems: uvw and p. However, once this is created, the code will handle supplemental utilities. This option can only be used in the context of a momentum lumped mass matrix
Activate Projected Stress Stabilization
- Syntax
Activate Projected Stress Stabilization
- Summary
Activate full momentum stress term for residual stabilization
- Description
Activate full momentum stress term for residual stabilization
Activate Scv Nodal Gradient
- Syntax
Activate Scv Nodal Gradient
- Summary
Use scv nodal gradient for MUSCL and edge-based diffusion terms
- Description
Use scv nodal gradient for MUSCL and edge-based diffusion terms; default is to use nodal grad based on Green Gauss over the duel mesh with edge based integration points.
Activate Shakib Scaling
- Syntax
Activate Shakib Scaling
- Summary
Specify Shakib scaling; temp line command
Activate Vrtm In Mass Flux Vector
- Syntax
Activate Vrtm In Mass Flux Vector
- Summary
Activate velocity relative to mesh in mass flux vector
- Description
In some cases, the volume may be constant, although there is mesh motion. This is the case in wind energy sliding mesh applications. This algorithm pays not attention to GCL and assumes that the time rate of volume is zero. Again, this is fine in solid rotation.
Ausm Alpha
- Syntax
Ausm Alpha alpha
- Summary
Set constant alpha in Mach splitting function.
- Description
Default is 0, unless ausm+ is chosen, then the default is 3/16.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
alpha |
real |
0.0 |
Ausm Beta
- Syntax
Ausm Beta beta
- Summary
Set constant beta in Mach splitting function.
- Description
Default is 0, unless ausm+ is chosen, then the default is 1/8..
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
beta |
real |
0.0 |
Clip Cvfem Level Set Dof
- Syntax
Clip Cvfem Level Set Dof
- Summary
Clip level set; only germane for conserved level set formulation that has bounds between zero and unity
First Order Upwind Factor
- Syntax
First Order Upwind Factor RealValue For Equation EquationString [ SpeciesName | MaterialPhaseName]
- Summary
First-order upwind factor,
.
- Description
This value specifies the explicit upwind blending between pure upwind and the chosen convection operator, e.g., UPW*(firstOrderUpwind) + (1-firstOrderUpwind)*(blendedUpwindCentral).
where UPW is the pure first order upwind value and blendedUpwindCentral is a blend between the selected upwind method and central difference operator based on the local cell Peclet number (see Hybrid Upwind Factor line command).
For now, the blendedUpwindCentral is pure central.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
RealValue |
real |
1.0 |
EquationString |
string |
– |
{of | species} |
– |
|
SpeciesName |
string |
– |
{in | material_phase} |
– |
|
MaterialPhaseName |
string |
– |
Flux Scheme
- Syntax
Flux Scheme
- Summary
Set flux scheme used by all equations in the high-Mach CVFEM formulation.
- Description
Set flux scheme used by all equations in the high-Mach CVFEM formulation.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{ausm | ausm_plus | roe | van_leer} |
– |
Freeze Muscl Limiter At Global Step
- Syntax
Freeze Muscl Limiter At Global Step freezeStep
- Summary
Freeze MUSCL limiter at a given global step
- Description
Freeze the MUSCL limiter
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
freezeStep |
real |
– |
Hybrid Upwind Factor
- Syntax
Hybrid Upwind Factor RealValue For Equation EquationString [ SpeciesName | MaterialPhaseName]
- Summary
Hybrid upwind factor dials in blending between user specified operator and central.
- Description
Allows blending of the Peclet factor. A value of zero produces pure central. Higher values blend more user specified upwind (currently, pure first order upwind).
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
RealValue |
real |
1.0 |
EquationString |
string |
– |
{of | species} |
– |
|
SpeciesName |
string |
– |
{in | material_phase} |
– |
|
MaterialPhaseName |
string |
– |
Interpolate Density And Velocity Separately In Mass Flux Vector
- Syntax
Interpolate Density And Velocity Separately In Mass Flux Vector
- Summary
use (rho)ip*(uj)ip rather than default (rho*uj)ip
Lag Nodal Pressure Gradient In Mass Flux Vector Expression
- Syntax
Lag Nodal Pressure Gradient In Mass Flux Vector Expression
- Summary
Compute the nodal pressure gradient calculation.
- Description
Lag the nodal pressure gradient assembly for use in the stabilized mass flux vector expression. This command will place the calculation at the top of the non-linear iteration. In general, it will not be wise to use this option for steady simulations as there is one nonlinear loop.
Lag Nodal Tau In Mass Flux Vector Expression
- Syntax
Lag Nodal Tau In Mass Flux Vector Expression
- Summary
Compute the nodal tau calculation.
- Description
Lag the nodal tau assembly for use in the stabilized mass flux vector expression. This command will place the calculation at the top of the non-linear iteration. In general, it will not be wise to use this option for steady simulations as there is one nonlinear loop.
Muscl Limiter
- Syntax
Muscl Limiter For Equation EquationString [ SpeciesName | MaterialPhaseName]
- Summary
Specify the MUSCL limiter method.
- Description
TVD limiter.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{muscl_minmod | muscl_none | muscl_superbee | muscl_van_albada | muscl_van_leer} |
– |
|
EquationString |
string |
– |
{of | species} |
– |
|
SpeciesName |
string |
– |
{in | material_phase} |
– |
|
MaterialPhaseName |
string |
– |
Omit Diffusion Term From Sucv Tau
- Syntax
Omit Diffusion Term From Sucv Tau
- Summary
Do not use timestep in the expression for the SUCV stabilization coefficient
Omit Disting Bc Ip Sensitivities
- Syntax
Omit Disting Bc Ip Sensitivities
- Summary
Drop distinguishing bc sensitivities for ip values.
- Description
Drop distinguishing bc sensitivities for ip values.
Omit Dt Term From Sucv Tau
- Syntax
Omit Dt Term From Sucv Tau
- Summary
Do not use timestep in the expression for the SUCV stabilization coefficient
Pressure Stabilization Characteristic Length
- Syntax
Pressure Stabilization Characteristic Length CharLength
- Summary
Specify a constant length scale to compute tau; only applicable for characteristic scaling
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
CharLength |
real |
– |
Pressure Stabilization Order
- Syntax
Pressure Stabilization Order
- Summary
Order of pressure stabilization
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{fourth_order | second_order | zeroth_order} |
– |
Pressure Stabilization Parameter Scaling
- Syntax
Pressure Stabilization Parameter Scaling TauScaling
- Summary
Scaling of tau
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
TauScaling |
real |
– |
Pressure Stabilization Scaling
- Syntax
Pressure Stabilization Scaling [ With Value ConstantTau ]
- Summary
Scaling coefficient for pressure stabilization
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{characteristic | constant | shakib | stabilized | time_step} |
– |
Roe Entropy Fix C
- Syntax
Roe Entropy Fix C epsc
- Summary
Small constant for entropy fix (modification of |U +/- c| eigenvalues in Roe scheme)
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
epsc |
real |
0.1 |
Roe Entropy Fix U
- Syntax
Roe Entropy Fix U epsu
- Summary
Small constant for entropy fix (modification of |U| eigenvalues in Roe scheme)
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
epsu |
real |
0.1 |
Upwind Method
- Syntax
Upwind Method For Equation EquationString [ SpeciesName | MaterialPhaseName]
- Summary
Specify method that is blended with pure second order.
- Description
This user defined method will be blended with pure second order based on cell Peclet blending. In most cases, this operator is upwinded, however, in the case of 4th order a higher order centered scheme is used.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{fourth | gupw | muscl | sucv | upw} |
UPW |
|
EquationString |
string |
– |
{of | species} |
– |
|
SpeciesName |
string |
– |
{in | material_phase} |
– |
|
MaterialPhaseName |
string |
– |
Use Approximate Roe Sensitivities
- Syntax
Use Approximate Roe Sensitivities
- Summary
Use approximate Roe sensitivities for the LHS instead of Van Leer
- Description
By default, the Roe flux uses the sensitivities for the Van Leer flux scheme form the LHS matrix. This command turns on a different approximation, based more closely on the Roe flux itself; this approximation converges more quickly for some problems, but is less robust for others. Currently this option only has an effect when the “NC_ADV” equation term is used.
Use Opposing Subface In Open Mass Flux
- Syntax
Use Opposing Subface In Open Mass Flux
- Summary
Open mass flux will be computed using the interpolated pressure at the opposing subface
Use Specified Pressure In Open Mass Flux
- Syntax
Use Specified Pressure In Open Mass Flux
- Summary
User specified pressure in open BC will be used to compute gradp in open mass flux BC
7.38.1.3. Edc Model Specification
- Summary
Specify EDC combustion model options.
begin Edc Model Specification EdcSpecName Activate Co2 Dissociation Model Activate Hydrogen Dissociation Model Activate Ignition Model IgnPart Activate Laminar Limit Model Activate Lumped Source Term Model Activate Separate Co Irreversible Oxidation Pathway Activation Time Time Fuel Name Fuel Ignition Threshold Temperature IgnTemp Minimum Product Fraction Prmin Reaction Time Scale Tchem Reference Property Value Reference Property Of SpeciesName Value begin Oxidizer Mixture Specification OxMixName end end Edc Model Specification EdcSpecName
7.38.1.3.1. Line Commands
Activate Co2 Dissociation Model
- Syntax
Activate Co2 Dissociation Model
- Summary
Include effects of CO2 dissociation into CO and O2 at high temperatures
- Description
At high temperatures, the equilibrium between CO2, CO, and O2 shifts away from CO2, which can significantly decrease the flame temperature. Activating this model will add this effect to the standard EDC combustion model.
Activate Hydrogen Dissociation Model
- Syntax
Activate Hydrogen Dissociation Model
- Summary
Include effects of H2 dissociation into H
- Description
At temperatures greater than about 2000K, the equilibrium between H2 and H will yield non-negligible concentrations of H which can significantly decrease flame temperatures. Activating this model will add this effect to the standard EDC combustion model using the correlations of W.W. Erikson, which are derived from the NASA CEA code [59, 60].
Note that the H species must be included in the Cantera input XML file, and neither H nor H2 should be the “last” species in the list since this species is not independent of the rest (to enforce unity sum) and may be susceptible to more noise than the others. Since temperature and other properties are very sensitive to oscillations in the H and H2 equilibrium, this noise could be problematic.
Activate Ignition Model
- Syntax
Activate Ignition Model IgnPart
- Summary
MeshPart on which to use the EDC ignition model
- Description
Turn on the ignition model for this MeshPart. If fuel and oxidizer are present and the temperature is below the ignition threshold temperature everywhere in the part, reaction will begin. Volume block names and surface names are valid for this command, as well as the alias “all_blocks” and “all_surfaces”. Multiple parts must be specified with multiple instances of this line command.
Parameter |
Value |
Default |
|---|---|---|
{@ | at | for | in | on | over} |
– |
|
IgnPart |
string |
– |
Activate Laminar Limit Model
- Syntax
Activate Laminar Limit Model
- Summary
Turn on the EDC laminar limit model for low-turbulence situations
- Description
Turn on the EDC laminar limit model. This model requires setting three model constants: CtauLam, CgammaLam, and ClamTrans. The model uses a time scale based on a velocity gradient rather than the turb_ke/turb_diss. This appropriate time scale permits the flame to anchor in laminar regions.
Activate Lumped Source Term Model
- Syntax
Activate Lumped Source Term Model
- Summary
Nodally lump the EDC source term
- Description
If set, the EDC source terms are nodally lumped, rather than using the default implementation of a consistent approach at the Gauss points.
Activate Separate Co Irreversible Oxidation Pathway
- Syntax
Activate Separate Co Irreversible Oxidation Pathway
- Summary
Add CO oxidation pathway as a separate reaction pathway. This should really be used only in the context of a propellant fire in the presence of hydrogen combustion.
Activation Time
- Syntax
Activation Time Time
- Summary
The time at which the EDC combustion model is activated. No combustion will occur before this time.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
Time |
real |
0.0 |
Fuel Name
- Syntax
Fuel Name Fuel
- Summary
The name of the EDC fuel species, typically either H2 or a major hydrocarbon
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
Fuel |
string |
– |
Ignition Threshold Temperature
- Syntax
Ignition Threshold Temperature IgnTemp
- Summary
The temperature below which the ignition model is activated
- Description
If the ignition model is requested (through the “ACTIVATE IGNITION MODEL” line command, then it will be activated if all temperatures in the corresponding block are below this temperature.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
IgnTemp |
real |
1000 K |
Minimum Product Fraction
- Syntax
Minimum Product Fraction Prmin
- Summary
The minimum product fraction, below which the EDC model will be deactivated.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
Prmin |
real |
1.0e-6 |
Reaction Time Scale
- Syntax
Reaction Time Scale Tchem
- Summary
Reaction time scale to set extinction
- Description
Characteristic time scale of the chemical kinetics. Residence time in the fine structure region will be compared to this to determine if extinction will result.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
Tchem |
real |
7.0e-5 |
Reference
- Syntax
Reference Property Value
- Summary
Reference property for initial diagnostic output
- Description
If all required properties are set, the EDC model will print the adiabatic flame temperature and heat of combustion for the mechanism defined by the specified fuel.
Parameter |
Value |
Default |
|---|---|---|
Property |
string |
– |
{= | are | is} |
– |
|
Value |
real |
– |
Reference
- Syntax
Reference Property Of SpeciesName Value
- Summary
Reference species-dimensioned property for initial diagnostic output
- Description
If all required properties are set, the EDC model will print the adiabatic flame temperature and heat of combustion for the mechanism defined by the specified fuel.
Parameter |
Value |
Default |
|---|---|---|
Property |
string |
– |
SpeciesName |
string |
– |
{= | are | is} |
– |
|
Value |
real |
– |
7.38.1.3.2. Oxidizer Mixture Specification
- Summary
Specify either mass fractions or mole fractions for the oxidizer mixture. Only non-zero species need to be included, and the mass or mole fractions must sum to unity. The default is air, with a 0.2095:0.7905 molar ratio between O2 and N2.
begin Oxidizer Mixture Specification OxMixName Mass_Fraction SpeciesName Value Mole_Fraction SpeciesName Value end Oxidizer Mixture Specification OxMixName
Line Commands
Mass_Fraction
- Syntax
Mass_Fraction SpeciesName Value
- Summary
Oxidizer mixture mass fraction for the given species
Parameter |
Value |
Default |
|---|---|---|
SpeciesName |
string |
– |
{= | are | is} |
– |
|
Value |
real |
– |
Mole_Fraction
- Syntax
Mole_Fraction SpeciesName Value
- Summary
Oxidizer mixture mole fraction for the given species
Parameter |
Value |
Default |
|---|---|---|
SpeciesName |
string |
– |
{= | are | is} |
– |
|
Value |
real |
– |
7.38.1.4. Hdiff Model Specification
- Summary
Specify hydrogen diffusion model options
begin Hdiff Model Specification HdiffOptionsName Use Reference System Flux end Hdiff Model Specification HdiffOptionsName
7.38.1.4.1. Line Commands
Use Reference System Flux
- Syntax
Use Reference System Flux
- Summary
Use flux defined in the reference (if true) or current (if false) coordinate system.
- Description
If the hydrogen flux is written in the current configuration coordinate system, the formulation includes a tensor multiplication by the inverse right Cauchy-Green tensor. This gives the most accurate formulation when the entire equation is being solved in the current configuration. If the flux is written in the reference system (i.e. the parameter value is “true”), no such tensor multiplication is included.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{false | no | off | on | true | yes} |
TRUE |
7.38.1.5. Porous Flow Options
- Summary
Specify solution options for porous flow.
begin Porous Flow Options blockName Integrate Advection By Parts Use Cvfem end Porous Flow Options blockName
7.38.1.5.1. Line Commands
Integrate Advection By Parts
- Syntax
Integrate Advection By Parts
- Summary
Do you wish to integrate the advection associated with porous flow species by parts?
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{false | no | off | on | true | yes} |
– |
Use Cvfem
- Syntax
Use Cvfem
- Summary
Specify whether to use CVFEM or Galerkin discretization.
Default is Galerkin.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{false | no | off | on | true | yes} |
– |
7.38.1.6. Species Options
- Summary
Specify solution options for species equations
begin Species Options blockName Use Cvfem end Species Options blockName
7.38.1.6.1. Line Commands
Use Cvfem
- Syntax
Use Cvfem
- Summary
Specify whether to use CVFEM or Galerkin discretization. Default is Galerkin.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{false | no | off | on | true | yes} |
– |
7.38.1.7. Turbulence Model Specification
- Summary
Specify turbulence modeling options.
begin Turbulence Model Specification TurbSpecName Activate Cvfem Lumped Turbulent Source Term Algorithm Activate Kepsilon Source Term Trickster Linearization Activate New Komega Src Linearization Activate Rhs Sdr Sensitivities To Activate Rhs Tke Sensitivities To Activate Turbulence Clipping Utility At Implicit Les Filter Scale Value Limit Turbulent Ke Production To Value Times Dissipation Omit Finite Difference Sensitivity Due To Utau Omit Sensitivities In Turbulent Production Term Omit Sensitivities To Turbulent Production From Ke Source Only Omit Velocity Divergence In Turbulent Production Term Time Filter Value Turbulence Model Turbulence Model Parameter Value end Turbulence Model Specification TurbSpecName
7.38.1.7.1. Line Commands
Activate Cvfem Lumped Turbulent Source Term Algorithm
- Syntax
Activate Cvfem Lumped Turbulent Source Term Algorithm
- Summary
Lump cvfem turbulent ke, tdr and ksgs rhs source terms
- Description
This is appropriate for CVFEM only as it uses a special flavor of lumping source terms.
Activate Kepsilon Source Term Trickster Linearization
- Syntax
Activate Kepsilon Source Term Trickster Linearization
- Summary
Follow classic Patankar approach to linearization of k rhs
- Description
The dissipation rate in the k equation includes sensitivities to k by using the Prandtl Kolmorgorov relationship to for the model for of the dissipation rate. This procedure provides additional diagonal dominance for the k rhs source term.
Activate New Komega Src Linearization
- Syntax
Activate New Komega Src Linearization
- Summary
Alternate komega src linearization
- Description
Alt komega src linearization
Activate Rhs Sdr Sensitivities To
- Syntax
Activate Rhs Sdr Sensitivities To
- Summary
Dial in rhs sens for sdr equation
Parameter |
Value |
Default |
|---|---|---|
{dens_sens | sdr_sens | tke_sens | turb_prod_sens | tvisc_sens} |
– |
Activate Rhs Tke Sensitivities To
- Syntax
Activate Rhs Tke Sensitivities To
- Summary
Dial in rhs sens for tke equation
Parameter |
Value |
Default |
|---|---|---|
{dens_sens | sdr_sens | tke_sens | turb_prod_sens | tvisc_sens} |
– |
Activate Turbulence Clipping Utility At
- Syntax
Activate Turbulence Clipping Utility At
- Summary
Activate clipping utility for turbulence quantities
- Description
Sometimes it helps to clip the turbulence quantities. This is a utility that provides this support.
Parameter |
Value |
Default |
|---|---|---|
{begin_nonlinear_solve | end_nonlinear_solve | manually_run | post_iterate | post_linear_solve | post_nonlinear_solve | pre_iterate | pre_linear_solve | pre_nonlinear_solve | run_initially | run_once | run_post_linear_system_initialization} |
– |
Implicit Les Filter Scale
- Syntax
Implicit Les Filter Scale Value
- Summary
Provide implicit filter length
- Description
In constant coefficient LES models, allow the user to specify and implicit filter length. The default is to determine a length scale tied to the mesh.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
Value |
real |
– |
Limit Turbulent Ke Production
- Syntax
Limit Turbulent Ke Production To Value Times Dissipation
- Summary
Choose to limit production source terms
- Description
This option limits the turbulent ke production to a scale factor of dissipation, prod = min(prod, limit*den*en1). In practice, the ratio of production to dissipation is not very high. In some flows, it is useful to specify a value of approximately 1000. The ratio should be checked as part of the analysis to make sure that violation of the physical ratio has not been done. In general, this option is only activated in domain locations where dissipation rate is very small.
Parameter |
Value |
Default |
|---|---|---|
Value |
real |
1.0e-8 |
Omit Finite Difference Sensitivity Due To Utau
- Syntax
Omit Finite Difference Sensitivity Due To Utau
- Summary
Omit FD sensitivity from utau
- Description
The wall friction velocity, utau, can be complex to evaluate in the context of the law of the wall. The default is to compute sensitivities via finite difference. Sometimes, this seems to add some overhead and spurious sensitivities.
Omit Sensitivities In Turbulent Production Term
- Syntax
Omit Sensitivities In Turbulent Production Term
- Summary
Do not include sensitivities for turbulence production
- Description
This option removes the analytical sensitivities for the production of turbulent kinetic energy. It seems that most simulations are more stable if this option is activated.
Omit Sensitivities To Turbulent Production From Ke Source Only
- Syntax
Omit Sensitivities To Turbulent Production From Ke Source Only
- Summary
Omit sensitivities to turbulence production from the KE source term
- Description
This option removes the analytical sensitivities for the production of turbulent kinetic energy in the KE source terms (where they may be destabilizing) but retains them elsewhere (where they may be helpful). Mutually exclusive w/ the previous option.
Omit Velocity Divergence In Turbulent Production Term
- Syntax
Omit Velocity Divergence In Turbulent Production Term
- Summary
Do not include divergence term in turbulence production
- Description
This option removes the divergence term from the turbulent production of kinetic energy. The default is to include this term.
Time Filter
- Syntax
Time Filter Value
- Summary
Time filter size for Time Filtered Navier-Stokes model
- Description
Turbulent viscosity is normally calculated based on a time scale given by k/epsilon (for k-epsilon models) or T (v2f model). The TFNS model substitutes the minimum of the normal computed value and the user-specified time filter size in the turbulent viscosity calculation. In general, this filter should be no less than twice the physical time step. A non-fatal warning is issued if this condition is violated.
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
Value |
real |
1.0e32 |
Turbulence Model
- Syntax
Turbulence Model
- Summary
Specify type of turbulence model to be used
Parameter |
Value |
Default |
|---|---|---|
{= | are | is} |
– |
|
{dsmag | kepsilon | komega | ksgs | laminar | sarans | smag | sst} |
– |
Turbulence Model Parameter
- Syntax
Turbulence Model Parameter Value
- Summary
Turbulence model parameters
Parameter |
Value |
Default |
|---|---|---|
{a_1 | beta | beta_1 | beta_star | c_epsilon | c_epsilon_1 | c_epsilon_2 | c_mu | c_mu_cs | c_mu_epsilon | edc_c_gamma_lam | edc_c_lam_trans | edc_c_tau_lam | gamma | gamma_1 | kappa | lr_omega | minimum_turbulent_viscosity | pr_t | ramp_time | sa_cb1 | sa_cb2 | sa_cv1 | sa_cw2 | sa_cw3 | sa_sigma | sc_t | sigma_epsilon_lam | sigma_epsilon_trb | sigma_k1_trb | sigma_k_lam | sigma_k_trb | sigma_omega1_trb | sigma_omega_lam | sigma_omega_trb | von_karman | wall_length_factor | y_plus_crit} |
– |
|
{= | are | is} |
– |
|
Value |
real |
– |