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cs_equation_param_t Struct Reference

Set of parameters to handle an unsteady convection-diffusion-reaction equation with term sources. More...

#include <cs_equation_param.h>

Collaboration diagram for cs_equation_param_t:

Data Fields

bool time_control_owner
cs_time_control_t * time_control
General settings
char *restrict name
cs_equation_type_t type
int dim
union { 
   int   verbosity 
   int   iwarni 
}; 
cs_flag_t flag
cs_flag_t post_flag
cs_param_space_scheme_t space_scheme
cs_param_dof_reduction_t dof_reduction
int space_poly_degree
Legacy Settings
int iconv
int istat
int idircl
int ndircl
int idiff
int idifft
int idften
int iswdyn
int ischcv
int ibdtso
int isstpc
int nswrgr
int nswrsm
int imvisf
int imrgra
int imligr
int ircflu
int iwgrec
int icoupl
union { 
   double   theta 
   double   thetav 
}; 
double blencv
double blend_st
double epsilo
double epsrsm
double epsrgr
double climgr
cs_real_t b_climgr
double relaxv
int b_gradient_r
int b_diff_flux_rc
Settings for the boundary conditions
cs_param_bc_type_t default_bc
int n_bc_defs
cs_xdef_t ** bc_defs
cs_param_bc_enforce_t default_enforcement
cs_real_t strong_pena_bc_coeff
cs_real_t weak_pena_bc_coeff
Numerical settings for the time-dependent parameters
int n_ic_defs
cs_xdef_t ** ic_defs
bool do_lumping
cs_hodge_param_t time_hodgep
cs_property_t * time_property
cs_param_time_scheme_t time_scheme
Numerical settings for the diffusion (Laplacian div-grad) term
cs_hodge_param_t diffusion_hodgep
cs_property_t * diffusion_property
Numerical settings for the curl-curl term
cs_hodge_param_t curlcurl_hodgep
cs_property_t * curlcurl_property
Numerical settings for the grad-div term
cs_hodge_param_t graddiv_hodgep
cs_property_t * graddiv_property
Numerical settings for the advection term
cs_param_advection_form_t adv_formulation
cs_param_advection_scheme_t adv_scheme
cs_param_advection_strategy_t adv_strategy
cs_param_advection_extrapol_t adv_extrapol
cs_real_t upwind_portion
double cip_scaling_coef
cs_adv_field_t * adv_field
cs_property_t * adv_scaling_property
Numerical settings for the reaction term

The contribution of a reaction term to the algebraic system is either at the left-hand and/or right-hand side according to the choice of time scheme

cs_hodge_param_t reaction_hodgep
int n_reaction_terms
cs_property_t ** reaction_properties
Definition of the related source terms

The contribution of a source term to the algebraic system is always at right-hand side whatever is the choice of time scheme

int n_source_terms
cs_xdef_t ** source_terms
Definition of the related volume mass injection

The contribution of a volume mass injection to the algebraic system is always at right-hand side whatever is the choice of time scheme, and is defined in a manner similar to boundary conditions. For variables whose injection value matches the "ambient" value, no term needs to be added.

int n_volume_mass_injections
cs_xdef_t ** volume_mass_injections
Enforcement of values inside the computational domain

This is different from the enforcement of boundary conditions but rely on the same algebraic manipulation. Only an algebraic manipulation is used to enforce interior/border DoFs.

int n_enforcements
cs_enforcement_param_t ** enforcement_params
Settings related to the resolution of the algebraic system
cs_param_sles_t * sles_param
cs_param_saddle_t * saddle_param
cs_param_nl_algo_t incremental_algo_type
cs_param_convergence_t incremental_algo_cvg
cs_real_t incremental_relax_factor
cs_iter_algo_param_aac_t incremental_anderson_param

Detailed Description

Set of parameters to handle an unsteady convection-diffusion-reaction equation with term sources.

Field Documentation

◆ [union]

union { ... }

Indicate if the convection is taken into account (1) or not (0). By default, 0 for the pressure or f in v2f model, 1 for the other unknowns.

◆ [union]

union { ... }

name of the equation

◆ adv_extrapol

cs_param_advection_extrapol_t adv_extrapol

Extrapolation used to estimate the advection field (please refer to cs_param_advection_extrapol_t)

◆ adv_field

cs_adv_field_t* adv_field

Pointer to the cs_adv_field_t structure associated to the advection term

◆ adv_formulation

cs_param_advection_form_t adv_formulation

Type of formulation (conservative, non-conservative...) for the advective term

◆ adv_scaling_property

cs_property_t* adv_scaling_property

May be set to NULL even if the advection term is activated. The value of this property in each cell is a multiplicative coefficient in front of the advection term (boundary terms are also considered) This is useful to treat the thermal module using the variable temperature instead of the enthalpy for instance or in the solidification module.

◆ adv_scheme

cs_param_advection_scheme_t adv_scheme

Numerical scheme used for the discretization of the advection term

◆ adv_strategy

cs_param_advection_strategy_t adv_strategy

Strategy used to handle the advection term (please refer to cs_param_advection_strategy_t)

◆ b_climgr

cs_real_t b_climgr

For least squares gradients, boundary factor of gradient limitation (high value means little limitation).
Relevant for all the variables using least-squares gradients for which imligr > CS_GRADIENT_LIMIT_NONE.

◆ b_diff_flux_rc

int b_diff_flux_rc

Indicate whether the fluxes (convective and diffusive) and boundary conditions at the faces should be reconstructed:

  • 0: no reconstruction
  • 1: reconstruction
  • Finer-grained limiters may be added in the future. Deactivating the reconstruction of the fluxes can have a stabilizing effect on the calculation, and help follow the maximum principal, with less degradation of the global precision than deactivating the reconstruction on the volume mesh.

◆ b_gradient_r

int b_gradient_r

Type of boundary gradient reconstruction Same codes as for imrgra (default is 2: least-squares, using extended neighborhood if available)

◆ bc_defs

cs_xdef_t** bc_defs

Pointers to the definitions of the boundary conditions

◆ blencv

double blencv

Proportion of second-order convective scheme (0 corresponds to an upwind first-order scheme); in case of LES calculation, a second-order scheme is recommended and activated by default (blencv = 1).
Relevant where iconv = 1.

◆ blend_st

double blend_st

Proportion of second-order convective scheme (0 corresponds to an upwind first-order scheme) after the slope test is activated; in case of LES calculation, a second-order scheme is recommended and activated by default (blend_st = 1).
Relevant whereiconv = 1.

◆ cip_scaling_coef

double cip_scaling_coef

Value of the scaling coefficient in front of the stabilization term when a CIP scheme is used (cf. CS_PARAM_ADVECTION_SCHEME_CIP or CS_PARAM_ADVECTION_SCHEME_CIP_CW). By default, this is set to -1.0 and later modified automatically if not modified by a user. Should be > 0.

◆ climgr

double climgr

For least squares gradients, volumic factor of gradient limitation (high value means little limitation).
Relevant for all the variables using least-squares gradients for which imligr > CS_GRADIENT_LIMIT_NONE.

◆ curlcurl_hodgep

cs_hodge_param_t curlcurl_hodgep

Set of parameters for the discrete Hodge operator related to the curl-curl operator

◆ curlcurl_property

cs_property_t* curlcurl_property

Pointer to the property related to the curl-curl term

◆ default_bc

cs_param_bc_type_t default_bc

Default boundary condition related to this equation. Valid choices:

◆ default_enforcement

cs_param_bc_enforce_t default_enforcement

Type of strategy to enforce an essential boundary conditions (Dirichlet for instance) when no predefined strategy is prescribed. See cs_param_bc_enforce_t for more details.

◆ diffusion_hodgep

cs_hodge_param_t diffusion_hodgep

Set of parameters for the discrete Hodge operator related to the diffusion

◆ diffusion_property

cs_property_t* diffusion_property

Pointer to the property related to the diffusion term

◆ dim

int dim

Dimension of the unknown

◆ do_lumping

bool do_lumping

Set to true or false. Activate several actions: Perform a mass lumping of the matrices related to the time and reaction discretization. All source terms are evaluated using a barycentric quadrature.

◆ dof_reduction

cs_param_dof_reduction_t dof_reduction

How is defined DoF

◆ enforcement_params

cs_enforcement_param_t** enforcement_params

Array of cs_enforcement_param_t structures storing the settings of each enforcement

◆ epsilo

double epsilo

Relative precision for the solution of the linear system. The default is epsilo = $ 10^-8 $. When there are enough iterations on the reconstruction of the right-hand side of the equation, the value may be increased (by default, in case of second-order in time, with nswrsm = 5 or 10, epsilo is increased to $ 10^-5 $.

◆ epsrgr

double epsrgr

Relative precision for the iterative gradient reconstruction. (when imrgra = 0).

◆ epsrsm

double epsrsm

Relative precision on the reconstruction of the right hand-side. The default is epsrsm = $ 10^-8 $. When there are not enough iterations on the reconstruction of the right-hand side of the equation, the value may be increased (by default, in case of second-order in time, with nswrsm = 5 or 10, epsrsm is increased to $ 10^-5 $ ).

◆ flag

cs_flag_t flag

Flag to know if unsteady or diffusion or convection or reaction or source terms are activated or not

◆ graddiv_hodgep

cs_hodge_param_t graddiv_hodgep

Set of parameters for the discrete Hodge operator related to the grad-div operator

◆ graddiv_property

cs_property_t* graddiv_property

Pointer to the property related to the grad-div term

◆ ibdtso

int ibdtso

Backward differential scheme in time order.

◆ ic_defs

cs_xdef_t** ic_defs

List of pointers to the definition of the inititial condition

◆ iconv

int iconv

Indicate if the convection is taken into account (1) or not (0). By default, 0 for the pressure or f in v2f model, 1 for the other unknowns.

◆ icoupl

int icoupl

Internal coupling indicator

  • -1: not coupled (default)
  • 1: coupled

◆ idften

int idften

Type of diffusivity flag (sum of mask constants defining if diffusivity is isotropic, anisotropic, ... Masks are defined in Transported scalars parameters).

◆ idiff

int idiff

Indifcate if diffusion is taken into account (1) or not (0).

◆ idifft

int idifft

When diffusion is taken into account (idiff = 1), indicate if the turbulent diffusion is taken into account (idifft = 1) or not (0).

◆ idircl

int idircl

Indicate whether the diagonal of the matrix should be slightly shifted if there is no Dirichlet boundary condition and if istat = 0 (0: false / 1: true). Indeed, in such a case, the matrix for the general advection/diffusion equation is singular. A slight shift in the diagonal will make it invertible again. By default, idircl is set to 1 for all the unknowns, except $\overline{f}$ in the v2f model (whose equation already contain another diagonal term).

Remarks
this code is defined automatically based on the presence of Dirichlet BCs.

◆ imligr

int imligr

Type of gradient limiter

  • -1 (CS_GRADIENT_LIMIT_NONE): no limitation
  • 0 (CS_GRADIENT_LIMIT_CELL): based on the neighbors
  • 1 (CS_GRADIENT_LIMIT_FACE): superior order

◆ imrgra

int imrgra

Type of gradient reconstruction

  • 0: iterative reconstruction of the non-orthogonalities
  • 1: least squares method based on the first neighbor cells (those which share a face with the treated cell)
  • 2, 3: least squares method using the extended neighborhood
  • 4: Green-Gauss based using the least squares method (first neighbors) to compute face values
  • 5, 6: Green-Gauss based using the least squares method with an extended neighborhood to compute face values
    If the computation fails due to mesh quality aspects, it is usually effective to use imrgra = 3, 5, or 6.

◆ imvisf

int imvisf

Face viscosity field interpolation

  • 0: aritmetic (default)
  • 1: harmonic

◆ incremental_algo_cvg

cs_param_convergence_t incremental_algo_cvg

Set of parameters to drive the convergence of the incremental algorithm

◆ incremental_algo_type

cs_param_nl_algo_t incremental_algo_type

Type of algorithm used to handle a (non-linear) incremental resolution

◆ incremental_anderson_param

cs_iter_algo_param_aac_t incremental_anderson_param

Set of parameters dedicated to the driving of the Anderson acceleration. This is only useful if the incremental_algo_type is set to the Anderson acceleration.

◆ incremental_relax_factor

cs_real_t incremental_relax_factor

strictly positive value for the relaxation of the incremental algorithm A recommanded range is between 0.5 and 0.9

◆ ircflu

int ircflu

Indicate whether the convective and diffusive fluxes at the faces should be reconstructed:

  • 0: no reconstruction
  • 1: reconstruction Deactivating the reconstruction of the fluxes can have a stabilizing effect on the calculation. It is sometimes useful with the $ k-\epsilon $ model, if the mesh is strongly non-orthogonal in the near-wall region, where the gradients of k and $ \epsilon $ are strong. In such a case, setting ircflu = 0 will probably help (switching to a first order convective scheme, blencv = 0, for k and $ \epsilon $ might also help in that case).

◆ ischcv

int ischcv

Indicate the type of second-order convective scheme

  • 0: Second Order Linear Upwind
  • 1: Centered
  • 2: Second Order with upwind-gradient reconstruction (SOLU)
  • 3: Blending between SOLU and Centered scheme
  • 4: NVD/TVD Scheme Then "limiter_choice" keyword must be set:
  • 0: Gamma
  • 1: SMART
  • 2: CUBISTA
  • 3: SUPERBEE
  • 4: MUSCL
  • 5: MINMOD
  • 6: CLAM
  • 7: STOIC
  • 8: OSHER
  • 9: WASEB — VOF scheme —
  • 10: M-HRIC
  • 11: M-CICSAM
  • 12: M-STACS

◆ isstpc

int isstpc

Indicate whether a slope test should be used to switch from a second-order to an upwind convective scheme under certain conditions, to ensure stability.

  • 0: slope test activated
  • 1: slope test deactivated
  • 2: continuous limiter ensuring boundedness (beta limiter) The use of the slope test stabilises the calculation but may reduce the spatial convergence order.

◆ istat

int istat

Indicate whether unsteady terms are present (1) or not (0) in the matrices. By default, 0 for the pressure or f in v2f model, 1 for the other unknowns.

◆ iswdyn

int iswdyn

Dynamic relaxation type:

  • 0 no dynamic relaxation
  • 1 dynamic relaxation depending on $ \delta \varia^k $
  • 2 dynamic relaxation depending on $ \delta \varia^k $ and $ \delta \varia^{k-1} $.

◆ iwarni

int iwarni
Deprecated
use verbosity instead (iwarni is an alias to verbosity)

◆ iwgrec

int iwgrec

Gradient calculation weighting

  • 0: standard
  • 1: weighted

◆ n_bc_defs

int n_bc_defs

Number of boundary conditions which are defined for this equation

◆ n_enforcements

int n_enforcements

Number of enforcements which have been specified

◆ n_ic_defs

int n_ic_defs

Number of definitions for setting the intial condition

◆ n_reaction_terms

int n_reaction_terms

Number of reaction terms to consider.

◆ n_source_terms

int n_source_terms

Number of source terms to consider.

◆ n_volume_mass_injections

int n_volume_mass_injections

Number of volume injections to consider.

◆ name

char* restrict name

name of the equation

◆ ndircl

int ndircl

Number of Dirichlet BCs

◆ nswrgr

int nswrgr

Iteration limit for the iterative gradient reconstruction (imrgra = 0). If imrgra = 0 and nswrgr <= 1, gradients are not reconstructed.

◆ nswrsm

int nswrsm

Iteration limit for the reconstruction of the right-hand sides of the equations with a first-order scheme in time (standard case), the default values are 2 for pressure and 1 for the other variables. With a second-order scheme in time (ischtp = 2) or LES, the default values are 5 for pressure and 10 for the other variables.

◆ post_flag

cs_flag_t post_flag

Flag to determine if predefined post-treatments such as Peclet, are requested

◆ reaction_hodgep

cs_hodge_param_t reaction_hodgep

Set of parameters for the discrete Hodge operator related to the reaction terms

◆ reaction_properties

cs_property_t** reaction_properties

List of properties associated to each reaction term

◆ relaxv

double relaxv

Relaxation coefficient for the associated variable. This relaxation parameter is only useful for the pressure with the unsteady algorithm (so as to improve the convergence in case of meshes of insufficient quality or of some turbulent models (k-epsilon, v2f, k-omega) and ikecou = 0; if ikecou = 1, relaxv is ignored.
Default values are 0.7 for turbulent variables and 1. for pressure. relaxv also stores the value of the relaxation coefficient when using the steady algorithm, deduced from the value of relxst (defaulting to relaxv = 1. - relxst).
Used only for the pressure and for turbulent variables ( $ k-\epsilon $, v2f or $ k-\omega $ models without coupling) with the unsteady algorithm. Always used with the steady algorithm.

◆ saddle_param

cs_param_saddle_t* saddle_param

Set of parameters to specify how to solve a saddle-point system. Up to now, only CDO cell-based schemes yield this type of problem. Other saddle-point problems arise when dealing with Stokes or Navier-Stokes equations with a monolithic velocity/pressure coupling. In the latter case, this is directly handled by the structures dedicated to the Navier-Stokes solver.

◆ sles_param

cs_param_sles_t* sles_param

Set of parameters to specify how to to solve the algebraic system

  • iterative solver
  • preconditioner
  • tolerance...

◆ source_terms

cs_xdef_t** source_terms

List of definition of each source term

◆ space_poly_degree

int space_poly_degree

Maximum degree of the polynomial basis

◆ space_scheme

cs_param_space_scheme_t space_scheme

Space discretization scheme

◆ strong_pena_bc_coeff

cs_real_t strong_pena_bc_coeff

Value of the penalization coefficient used to enforce the Dirichlet boundary conditions when CS_PARAM_BC_ENFORCE_PENALIZED is set. This value should be sufficiently large in order to neglect off-diagonal terms.

◆ theta

double theta

Value of $ \theta $ used to express at the second order the terms of convection, diffusion and the source terms which are linear functions of the solved variable, according to the formula $ \phi^{n+\theta} = (1-\theta) \phi^n + \theta \phi^{n+1} $. Generally, only the values 1 and 0.5 are used. The user is not allowed to modify this variable.

  • 1: first-order
  • 0.5: second-order
    For the pressure, theta is always 1. For the other variables, theta = 0.5 is used when the second-order time scheme is activated (ischtp = 2, standard for LES calculations), otherwise theta = 1.

◆ thetav

double thetav

◆ time_control

cs_time_control_t* time_control

◆ time_control_owner

bool time_control_owner

◆ time_hodgep

cs_hodge_param_t time_hodgep

Set of parameters for the discrete Hodge operator related to the unsteady term

◆ time_property

cs_property_t* time_property

Pointer to the cs_property_t structure related to the unsteady term

◆ time_scheme

cs_param_time_scheme_t time_scheme

Type of numerical scheme used for the time discretization

NB: theta is share with the legacy scheme

◆ type

cs_equation_type_t type

type of equation: predefined...

◆ upwind_portion

cs_real_t upwind_portion

Value between 0. and 1. (0: centered scheme, 1: pure upwind scheme) Introduce a constant portion of upwinding in a centered scheme Only useful if the advection scheme is set to CS_PARAM_ADVECTION_SCHEME_HYBRID_CENTERED_UPWIND

◆ verbosity

int verbosity

Verbosity for the resolution (0 or 1 for a reasonable log size, 2 or more for troubleshooting).

◆ volume_mass_injections

cs_xdef_t** volume_mass_injections

List of definitions of injection values

◆ weak_pena_bc_coeff

cs_real_t weak_pena_bc_coeff

Value of the penalization coefficient used to enforce the Dirichlet boundary condition when CS_PARAM_BC_ENFORCE_WEAK_NITSCHE or CS_PARAM_BC_ENFORCE_WEAK_SYM is set. This two latter strategies have a lesser influence on the conditioning number of the linear system than the choice CS_PARAM_BC_ENFORCE_PENALIZED

The documentation for this struct was generated from the following file: