schema_temps_base

Basic class for time schemes. This scheme will be associated with a problem and the equations of this problem.

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

euler_scheme

Synonyms: schema_euler_explicite, scheme_euler_explicit

Inherits from: schema_temps_base

This is the Euler explicit scheme.

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

leap_frog

Inherits from: schema_temps_base

This is the leap-frog scheme.

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

runge_kutta_ordre_2

Inherits from: schema_temps_base

This is a low-storage Runge-Kutta scheme of second order that uses 2 integration points. The method is presented by Williamson (case 1) in https://www.sciencedirect.com/science/article/pii/0021999180900339

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

runge_kutta_ordre_2_classique

Inherits from: schema_temps_base

This is a classical Runge-Kutta scheme of second order that uses 2 integration points.

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

runge_kutta_ordre_3

Inherits from: schema_temps_base

This is a low-storage Runge-Kutta scheme of third order that uses 3 integration points. The method is presented by Williamson (case 7) in https://www.sciencedirect.com/science/article/pii/0021999180900339

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

runge_kutta_ordre_3_classique

Inherits from: schema_temps_base

This is a classical Runge-Kutta scheme of third order that uses 3 integration points.

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

runge_kutta_ordre_4

Synonyms: runge_kutta_ordre_4_d3p

Inherits from: schema_temps_base

This is a low-storage Runge-Kutta scheme of fourth order that uses 3 integration points. The method is presented by Williamson (case 17) in https://www.sciencedirect.com/science/article/pii/0021999180900339

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

runge_kutta_ordre_4_classique

Inherits from: schema_temps_base

This is a classical Runge-Kutta scheme of fourth order that uses 4 integration points.

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

runge_kutta_ordre_4_classique_3_8

Inherits from: schema_temps_base

This is a classical Runge-Kutta scheme of fourth order that uses 4 integration points and the 3/8 rule.

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

runge_kutta_rationnel_ordre_2

Inherits from: schema_temps_base

This is the Runge-Kutta rational scheme of second order. The method is described in the note: Wambeck - Rational Runge-Kutta methods for solving systems of ordinary differential equations, at the link: https://link.springer.com/article/10.1007/BF02252381. Although rational methods require more computational work than linear ones, they can have some other properties, such as a stable behaviour with explicitness, which make them preferable. The CFD application of this RRK2 scheme is described in the note: https://link.springer.com/content/pdf/10.1007%2F3-540-13917-6_112.pdf.

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

schema_adams_bashforth_order_2

Inherits from: schema_temps_base

not_set

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

schema_adams_bashforth_order_3

Inherits from: schema_temps_base

not_set

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.

schema_predictor_corrector

Inherits from: schema_temps_base

This is the predictor-corrector scheme (second order). It is more accurate and economic than MacCormack scheme. It gives best results with a second ordre convective scheme like quick, centre (VDF).

Parameters:

[tinit] (type: float) Value of initial calculation time (0 by default).
[tmax] (type: float) Time during which the calculation will be stopped (1e30s by default).
[tcpumax] (type: float) CPU time limit (must be specified in hours) for which the calculation is stopped (1e30s by default).
[dt_min] (type: float) Minimum calculation time step (1e-16s by default).
[dt_max] (type: string) Maximum calculation time step as function of time (1e30s by default).
[dt_sauv] (type: float) Save time step value (1e30s by default). Every dt_sauv, fields are saved in the .sauv file. The file contains all the information saved over time. If this instruction is not entered, results are saved only upon calculation completion. To disable the writing of the .sauv files, you must specify 0. Note that dt_sauv is in terms of physical time (not cpu time).
[nb_sauv_max] (type: int) Maximum number of timesteps that will be stored in backup file (10 by default). This value is only useful when doing a complete backup of the calculation with parallel PDI (as it needs to allocate the proper amount of dataspace in advance). If this number is reached (ie we already stored the data of nb_sauv_max timesteps in the file), the next checkpoints will overwrite the first ones
[dt_impr] (type: float) Scheme parameter printing time step in time (1e30s by default). The time steps and the flux balances are printed (incorporated onto every side of processed domains) into the .out file.
[facsec] (type: string) Value assigned to the safety factor for the time step (1. by default). It can also be a function of time. The time step calculated is multiplied by the safety factor. The first thing to try when a calculation does not converge with an explicit time scheme is to reduce the facsec to 0.5. Warning: Some schemes needs a facsec lower than 1 (0.5 is a good start), for example Schema_Adams_Bashforth_order_3.
[seuil_statio] (type: float) Value of the convergence threshold (1e-12 by default). Problems using this type of time scheme converge when the derivatives dGi/dt of all the unknown transported values Gi have a combined absolute value less than this value. This is the keyword used to set the permanent rating threshold.
[residuals] (type: residuals) To specify how the residuals will be computed (default max norm, possible to choose L2-norm instead).
[diffusion_implicite] (type: int) Keyword to make the diffusive term in the Navier-Stokes equations implicit (in this case, it should be set to 1). The stability time step is then only based on the convection time step (dt=facsec*dt_convection). Thus, in some circumstances, an important gain is achieved with respect to the time step (large diffusion with respect to convection on tightened meshes). Caution: It is however recommended that the user avoids exceeding the convection time step by selecting a too large facsec value. Start with a facsec value of 1 and then increase it gradually if you wish to accelerate calculation. In addition, for a natural convection calculation with a zero initial velocity, in the first time step, the convection time is infinite and therefore dt=facsec*dt_max.
[seuil_diffusion_implicite] (type: float) This keyword changes the default value (1e-6) of convergency criteria for the resolution by conjugate gradient used for implicit diffusion.
[impr_diffusion_implicite] (type: int) Unactivate (default) or not the printing of the convergence during the resolution of the conjugate gradient.
[impr_extremums] (type: int) Print unknowns extremas
[no_error_if_not_converged_diffusion_implicite] (type: int) not_set
[no_conv_subiteration_diffusion_implicite] (type: int) not_set
[dt_start] (type: dt_start) dt_start dt_min : the first iteration is based on dt_min. dt_start dt_calc : the time step at first iteration is calculated in agreement with CFL condition. dt_start dt_fixe value : the first time step is fixed by the user (recommended when resuming calculation with Crank Nicholson temporal scheme to ensure continuity). By default, the first iteration is based on dt_calc.
[nb_pas_dt_max] (type: int) Maximum number of calculation time steps (1e9 by default).
[niter_max_diffusion_implicite] (type: int) This keyword changes the default value (number of unknowns) of the maximal iterations number in the conjugate gradient method used for implicit diffusion.
[precision_impr] (type: int) Optional keyword to define the digit number for flux values printed into .out files (by default 3).
[periode_sauvegarde_securite_en_heures] (type: float) To change the default period (23 hours) between the save of the fields in .sauv file.
[no_check_disk_space] (type: flag) To disable the check of the available amount of disk space during the calculation.
[disable_progress] (type: flag) To disable the writing of the .progress file.
[disable_dt_ev] (type: flag) To disable the writing of the .dt_ev file.
[adapt_dt_tmax] (type: flag) Use to adapt final dt when approaching tmax.
[gnuplot_header] (type: int) Optional keyword to modify the header of the .out files. Allows to use the column title instead of columns number.