mod_turb_hyd_ss_maille

Inherits from: modele_turbulence_hyd_deriv

Class for sub-grid turbulence model for Navier-Stokes equations.

Parameters:

[formulation_a_nb_points] (type: form_a_nb_points) The structure fonction is calculated on nb points and we should add the 2 directions (0:OX, 1:OY, 2:OZ) constituting the homegeneity planes. Example for channel flows, planes parallel to the walls.
[longueur_maille] (type: string into ['volume', 'volume_sans_lissage', 'scotti', 'arrete']) Different ways to calculate the characteristic length may be specified : volume : It is the default option. Characteristic length is based on the cubic root of the volume cells. A smoothing procedure is applied to avoid discontinuities of this quantity in VEF from a cell to another. volume_sans_lissage : For VEF only. Characteristic length is based on the cubic root of the volume cells (without smoothing procedure). scotti : Characteristic length is based on the cubic root of the volume cells and the Scotti correction is applied to take into account the stretching of the cell in the case of anisotropic meshes. arete : For VEF only. Characteristic length relies on the max edge (+ smoothing procedure) is taken into account.
[turbulence_paroi] (type: turbulence_paroi_base) Keyword to set the wall law.
[dt_impr_ustar] (type: float) This keyword is used to print the values (U +, d+, u$\star$) obtained with the wall laws into a file named datafile_ProblemName_Ustar.face and periode refers to the printing period, this value is expressed in seconds.
[dt_impr_ustar_mean_only] (type: dt_impr_ustar_mean_only) This keyword is used to print the mean values of u* ( obtained with the wall laws) on each boundary, into a file named datafile_ProblemName_Ustar_mean_only.out. periode refers to the printing period, this value is expressed in seconds. If you don\'t use the optional keyword boundaries, all the boundaries will be considered. If you use it, you must specify nb_boundaries which is the number of boundaries on which you want to calculate the mean values of u*, then you have to specify their names.
[nut_max] (type: float) Upper limitation of turbulent viscosity (default value 1.e8).
[correction_visco_turb_pour_controle_pas_de_temps] (type: flag) Keyword to set a limitation to low time steps due to high values of turbulent viscosity. The limit for turbulent viscosity is calculated so that diffusive time-step is equal or higher than convective time-step. For a stationary flow, the correction for turbulent viscosity should apply only during the first time steps and not when permanent state is reached. To check that, we could post process the corr_visco_turb field which is the correction of turbulent viscosity: it should be 1. on the whole domain.
[correction_visco_turb_pour_controle_pas_de_temps_parametre] (type: float) Keyword to set a limitation to low time steps due to high values of turbulent viscosity. The limit for turbulent viscosity is the ratio between diffusive time-step and convective time-step is higher or equal to the given value [0-1]

longueur_melange

Inherits from: mod_turb_hyd_ss_maille

This model is based on mixing length modelling. For a non academic configuration, formulation used in the code can be expressed basically as :

$nu_t=(Kappa.y)^2$.dU/dy

Till a maximum distance (dmax) set by the user in the data file, y is set equal to the distance from the wall (dist_w) calculated previously and saved in file Wall_length.xyz. [see Distance_paroi keyword]

Then (from y=dmax), y decreases as an exponential function : y=dmax*exp[-2.*(dist_w- dmax)/dmax]

Parameters:

[canalx] (type: float) [height] : plane channel according to Ox direction (for the moment, formulation in the code relies on fixed heigh : H=2).
[tuyauz] (type: float) [diameter] : pipe according to Oz direction (for the moment, formulation in the code relies on fixed diameter : D=2).
[dmax] (type: float) Maximum distance.
[fichier] (type: string) not_set
[fichier_ecriture_k_eps] (type: string) When a resume with k-epsilon model is envisaged, this keyword allows to generate external MED-format file with evaluation of k and epsilon quantities (based on eddy turbulent viscosity and turbulent characteristic length returned by mixing length model). The frequency of the MED file print is set equal to dt_impr_ustar. Moreover, k-eps MED field is automatically saved at the last time step. MED file is then used for resuming a K-Epsilon calculation with the Champ_Fonc_Med keyword.
[formulation_a_nb_points] (type: form_a_nb_points) The structure fonction is calculated on nb points and we should add the 2 directions (0:OX, 1:OY, 2:OZ) constituting the homegeneity planes. Example for channel flows, planes parallel to the walls.
[longueur_maille] (type: string into ['volume', 'volume_sans_lissage', 'scotti', 'arrete']) Different ways to calculate the characteristic length may be specified : volume : It is the default option. Characteristic length is based on the cubic root of the volume cells. A smoothing procedure is applied to avoid discontinuities of this quantity in VEF from a cell to another. volume_sans_lissage : For VEF only. Characteristic length is based on the cubic root of the volume cells (without smoothing procedure). scotti : Characteristic length is based on the cubic root of the volume cells and the Scotti correction is applied to take into account the stretching of the cell in the case of anisotropic meshes. arete : For VEF only. Characteristic length relies on the max edge (+ smoothing procedure) is taken into account.
[turbulence_paroi] (type: turbulence_paroi_base) Keyword to set the wall law.
[dt_impr_ustar] (type: float) This keyword is used to print the values (U +, d+, u$\star$) obtained with the wall laws into a file named datafile_ProblemName_Ustar.face and periode refers to the printing period, this value is expressed in seconds.
[dt_impr_ustar_mean_only] (type: dt_impr_ustar_mean_only) This keyword is used to print the mean values of u* ( obtained with the wall laws) on each boundary, into a file named datafile_ProblemName_Ustar_mean_only.out. periode refers to the printing period, this value is expressed in seconds. If you don\'t use the optional keyword boundaries, all the boundaries will be considered. If you use it, you must specify nb_boundaries which is the number of boundaries on which you want to calculate the mean values of u*, then you have to specify their names.
[nut_max] (type: float) Upper limitation of turbulent viscosity (default value 1.e8).
[correction_visco_turb_pour_controle_pas_de_temps] (type: flag) Keyword to set a limitation to low time steps due to high values of turbulent viscosity. The limit for turbulent viscosity is calculated so that diffusive time-step is equal or higher than convective time-step. For a stationary flow, the correction for turbulent viscosity should apply only during the first time steps and not when permanent state is reached. To check that, we could post process the corr_visco_turb field which is the correction of turbulent viscosity: it should be 1. on the whole domain.
[correction_visco_turb_pour_controle_pas_de_temps_parametre] (type: float) Keyword to set a limitation to low time steps due to high values of turbulent viscosity. The limit for turbulent viscosity is the ratio between diffusive time-step and convective time-step is higher or equal to the given value [0-1]

sous_maille_smago

Inherits from: mod_turb_hyd_ss_maille

Smagorinsky sub-grid turbulence model.

Nut=Cs1*Cs1*l*l*sqrt(2*S*S)

K=Cs2*Cs2*l*l*2*S

Parameters:

[cs] (type: float) This is an optional keyword and the value is used to set the constant used in the Smagorinsky model (This is currently only valid for Smagorinsky models and it is set to 0.18 by default) .
[formulation_a_nb_points] (type: form_a_nb_points) The structure fonction is calculated on nb points and we should add the 2 directions (0:OX, 1:OY, 2:OZ) constituting the homegeneity planes. Example for channel flows, planes parallel to the walls.
[longueur_maille] (type: string into ['volume', 'volume_sans_lissage', 'scotti', 'arrete']) Different ways to calculate the characteristic length may be specified : volume : It is the default option. Characteristic length is based on the cubic root of the volume cells. A smoothing procedure is applied to avoid discontinuities of this quantity in VEF from a cell to another. volume_sans_lissage : For VEF only. Characteristic length is based on the cubic root of the volume cells (without smoothing procedure). scotti : Characteristic length is based on the cubic root of the volume cells and the Scotti correction is applied to take into account the stretching of the cell in the case of anisotropic meshes. arete : For VEF only. Characteristic length relies on the max edge (+ smoothing procedure) is taken into account.
[turbulence_paroi] (type: turbulence_paroi_base) Keyword to set the wall law.
[dt_impr_ustar] (type: float) This keyword is used to print the values (U +, d+, u$\star$) obtained with the wall laws into a file named datafile_ProblemName_Ustar.face and periode refers to the printing period, this value is expressed in seconds.
[dt_impr_ustar_mean_only] (type: dt_impr_ustar_mean_only) This keyword is used to print the mean values of u* ( obtained with the wall laws) on each boundary, into a file named datafile_ProblemName_Ustar_mean_only.out. periode refers to the printing period, this value is expressed in seconds. If you don\'t use the optional keyword boundaries, all the boundaries will be considered. If you use it, you must specify nb_boundaries which is the number of boundaries on which you want to calculate the mean values of u*, then you have to specify their names.
[nut_max] (type: float) Upper limitation of turbulent viscosity (default value 1.e8).
[correction_visco_turb_pour_controle_pas_de_temps] (type: flag) Keyword to set a limitation to low time steps due to high values of turbulent viscosity. The limit for turbulent viscosity is calculated so that diffusive time-step is equal or higher than convective time-step. For a stationary flow, the correction for turbulent viscosity should apply only during the first time steps and not when permanent state is reached. To check that, we could post process the corr_visco_turb field which is the correction of turbulent viscosity: it should be 1. on the whole domain.
[correction_visco_turb_pour_controle_pas_de_temps_parametre] (type: float) Keyword to set a limitation to low time steps due to high values of turbulent viscosity. The limit for turbulent viscosity is the ratio between diffusive time-step and convective time-step is higher or equal to the given value [0-1]

sous_maille_wale

Inherits from: mod_turb_hyd_ss_maille

This is the WALE-model. It is a new sub-grid scale model for eddy-viscosity in LES that has the following properties :

it goes naturally to 0 at the wall (it doesn\'t need any information on the wall position or geometry)
it has the proper wall scaling in o(y3) in the vicinity of the wall
it reproduces correctly the laminar to turbulent transition.

Parameters:

[cw] (type: float) The unique parameter (constant) of the WALE-model (by default value 0.5).
[formulation_a_nb_points] (type: form_a_nb_points) The structure fonction is calculated on nb points and we should add the 2 directions (0:OX, 1:OY, 2:OZ) constituting the homegeneity planes. Example for channel flows, planes parallel to the walls.
[longueur_maille] (type: string into ['volume', 'volume_sans_lissage', 'scotti', 'arrete']) Different ways to calculate the characteristic length may be specified : volume : It is the default option. Characteristic length is based on the cubic root of the volume cells. A smoothing procedure is applied to avoid discontinuities of this quantity in VEF from a cell to another. volume_sans_lissage : For VEF only. Characteristic length is based on the cubic root of the volume cells (without smoothing procedure). scotti : Characteristic length is based on the cubic root of the volume cells and the Scotti correction is applied to take into account the stretching of the cell in the case of anisotropic meshes. arete : For VEF only. Characteristic length relies on the max edge (+ smoothing procedure) is taken into account.
[turbulence_paroi] (type: turbulence_paroi_base) Keyword to set the wall law.
[dt_impr_ustar] (type: float) This keyword is used to print the values (U +, d+, u$\star$) obtained with the wall laws into a file named datafile_ProblemName_Ustar.face and periode refers to the printing period, this value is expressed in seconds.
[dt_impr_ustar_mean_only] (type: dt_impr_ustar_mean_only) This keyword is used to print the mean values of u* ( obtained with the wall laws) on each boundary, into a file named datafile_ProblemName_Ustar_mean_only.out. periode refers to the printing period, this value is expressed in seconds. If you don\'t use the optional keyword boundaries, all the boundaries will be considered. If you use it, you must specify nb_boundaries which is the number of boundaries on which you want to calculate the mean values of u*, then you have to specify their names.
[nut_max] (type: float) Upper limitation of turbulent viscosity (default value 1.e8).
[correction_visco_turb_pour_controle_pas_de_temps] (type: flag) Keyword to set a limitation to low time steps due to high values of turbulent viscosity. The limit for turbulent viscosity is calculated so that diffusive time-step is equal or higher than convective time-step. For a stationary flow, the correction for turbulent viscosity should apply only during the first time steps and not when permanent state is reached. To check that, we could post process the corr_visco_turb field which is the correction of turbulent viscosity: it should be 1. on the whole domain.
[correction_visco_turb_pour_controle_pas_de_temps_parametre] (type: float) Keyword to set a limitation to low time steps due to high values of turbulent viscosity. The limit for turbulent viscosity is the ratio between diffusive time-step and convective time-step is higher or equal to the given value [0-1]