multiphase_numerics#

class ansys.fluent.core.solver.tui_231.main_menu.solve.set.multiphase_numerics(path, service)#

Bases: TUIMenu

Sets multiphase numerics options.

Classes:

advanced_stability_controls(path, service)

Enters the menu for the stability controls for multiphase flows.

boiling_parameters(path, service)

Enters the menu for the multiphase boiling model parameters.

compressible_flow(path, service)

Enters the compressible multiphase flow numerics menu.

default_controls(path, service)

Enters the default controls menu.

face_pressure_controls(path, service)

Enter the face pressure expert controls menu.

heat_mass_transfer(path, service)

Enters the menu for the multiphase heat mass transfer parameters.

porous_media(path, service)

Enters the porous media numerics menu.

solution_stabilization(path, service)

Enters the solution-stabilization numerics menu.

viscous_flow(path, service)

Enters the viscous multiphase flow numerics menu.
class advanced_stability_controls(path, service)#

Bases: TUIMenu

Enters the menu for the stability controls for multiphase flows. For more information about the below option, see and .

Classes:

anti_diffusion(path, service)

Enters the anti-diffusion menu.

equation_order(path, service)

Enters the equation order menu for homogeneous multiphase flow models.

hybrid_nita(path, service)

Enters the equation order menu for homogeneous multiphase flow models.

num_ventilation(path, service)

Numerical Ventilation Menu for VOF Model.

p_v_coupling(path, service)

Enters the menu for the pressure-velocity coupling controls.

pseudo_time(path, service)

Pseudo-Time stability controls for multiphase flow.
class anti_diffusion(path, service)#

Bases: TUIMenu

Enters the anti-diffusion menu. This item is available for VOF cases with the Interfacial Anti-Diffusion option enabled.

Methods:

enable_dynamic_strength(*args, **kwargs)

Enables dynamic strength to reduce compression in the direction tangential to the interface.

set_dynamic_strength_exponent(*args, **kwargs)

Sets the cosine exponent in the dynamic strength treatment in ).

set_maximum_dynamic_strength(*args, **kwargs)

Sets the maximum value of dynamic anti-diffusion strength in ).
enable_dynamic_strength(*args, **kwargs)#

Enables dynamic strength to reduce compression in the direction tangential to the interface.

set_dynamic_strength_exponent(*args, **kwargs)#

Sets the cosine exponent in the dynamic strength treatment in ).

set_maximum_dynamic_strength(*args, **kwargs)#

Sets the maximum value of dynamic anti-diffusion strength in ).

class equation_order(path, service)#

Bases: TUIMenu

Enters the equation order menu for homogeneous multiphase flow models.

Methods:

solve_exp_vof_at_end(*args, **kwargs)

Solve Explicit VOF at the end of time-step as an alternative.

solve_flow_last(*args, **kwargs)

When enabled, solves the flow equation at the end of the iteration.
solve_exp_vof_at_end(*args, **kwargs)#

Solve Explicit VOF at the end of time-step as an alternative.

solve_flow_last(*args, **kwargs)#

When enabled, solves the flow equation at the end of the iteration. This improves the behavior at the start of new time-step if the solution does not converge properly.

class hybrid_nita(path, service)#

Bases: TUIMenu

Enters the equation order menu for homogeneous multiphase flow models.

Methods:

initial_outer_iterations(*args, **kwargs)

Allows you to change the number of initial time-steps and the number of initial outer iterations to control solution stability.

outer_iterations(*args, **kwargs)

Sets the number of outer iterations.

Classes:

instability_detector(path, service)

Enters the menu for the instability detector controls.
initial_outer_iterations(*args, **kwargs)#

Allows you to change the number of initial time-steps and the number of initial outer iterations to control solution stability.

class instability_detector(path, service)#

Bases: TUIMenu

Enters the menu for the instability detector controls.

Methods:

enable_instability_detector(*args, **kwargs)

Enables/disables the instability detector to deal with possible instability problems.

set_cfl_limit(*args, **kwargs)

Sets the Courant number limit for detecting unstable events.

set_cfl_type(*args, **kwargs)

Selects the CFL number type for detection of an unstable event.

set_velocity_limit(*args, **kwargs)

Sets the velocity limit for detecting unstable events.

unstable_event_outer_iterations(*args, **kwargs)

Sets the number of outer iterations for an unstable event.
enable_instability_detector(*args, **kwargs)#

Enables/disables the instability detector to deal with possible instability problems. Once this option is enabled, additional instability detection options become available.

set_cfl_limit(*args, **kwargs)#

Sets the Courant number limit for detecting unstable events. This command becomes available once the enable-instability-detector? text option has been enabled.

set_cfl_type(*args, **kwargs)#

Selects the CFL number type for detection of an unstable event. This command becomes available once the enable-instability-detector? text option has been enabled.

set_velocity_limit(*args, **kwargs)#

Sets the velocity limit for detecting unstable events. This command becomes available once the enable-instability-detector? text option has been enabled.

unstable_event_outer_iterations(*args, **kwargs)#

Sets the number of outer iterations for an unstable event.

outer_iterations(*args, **kwargs)#

Sets the number of outer iterations.

class num_ventilation(path, service)#

Bases: TUIMenu

Numerical Ventilation Menu for VOF Model.

Methods:

enable(*args, **kwargs)

Enable numerical ventilation treatment to remove trapped phase adjacent to wall.

near_wall_treatment_options(*args, **kwargs)

Set near wall treatment options.

tau_estimation_options(*args, **kwargs)

Set time step size option for numerical ventilation treatment.

trapped_phase_vof_max(*args, **kwargs)

Set trapped phase maximum volume fraction to activate numerical ventilation treatment for non-trapped phases.

trapped_phase_vof_min(*args, **kwargs)

Set trapped phase minimum volume fraction to activate numerical ventilation treatment for trapped phase.
enable(*args, **kwargs)#

Enable numerical ventilation treatment to remove trapped phase adjacent to wall.

near_wall_treatment_options(*args, **kwargs)#

Set near wall treatment options.

tau_estimation_options(*args, **kwargs)#

Set time step size option for numerical ventilation treatment.

trapped_phase_vof_max(*args, **kwargs)#

Set trapped phase maximum volume fraction to activate numerical ventilation treatment for non-trapped phases.

trapped_phase_vof_min(*args, **kwargs)#

Set trapped phase minimum volume fraction to activate numerical ventilation treatment for trapped phase.

class p_v_coupling(path, service)#

Bases: TUIMenu

Enters the menu for the pressure-velocity coupling controls.

Classes:

coupled_vof(path, service)

Enters the stability control menu for VOF cases that involve the Coupled pressure-velocity coupling scheme.

rhie_chow_flux(path, service)

Enters the stability controls menu for the Rhie-Chow interpolation.

skewness_correction(path, service)

Enters the skewness correction menu.
class coupled_vof(path, service)#

Bases: TUIMenu

Enters the stability control menu for VOF cases that involve the Coupled pressure-velocity coupling scheme.

Methods:

buoyancy_force_linearization(*args, **kwargs)

Allows you to use the linearized buoyancy force and the blended treatment for the buoyancy force.
buoyancy_force_linearization(*args, **kwargs)#

Allows you to use the linearized buoyancy force and the blended treatment for the buoyancy force.

class rhie_chow_flux(path, service)#

Bases: TUIMenu

Enters the stability controls menu for the Rhie-Chow interpolation.

Methods:

low_order_rhie_chow(*args, **kwargs)

Enables/disables the low-order velocity interpolation in the flux calculation.
low_order_rhie_chow(*args, **kwargs)#

Enables/disables the low-order velocity interpolation in the flux calculation.

class skewness_correction(path, service)#

Bases: TUIMenu

Enters the skewness correction menu.

Methods:

limit_pressure_correction_gradient(*args, ...)

Enables/disables the limited pressure correction gradient in skewness terms for the PISO, SIMPLEC, or fractional step pressure-coupling schemes.
limit_pressure_correction_gradient(*args, **kwargs)#

Enables/disables the limited pressure correction gradient in skewness terms for the PISO, SIMPLEC, or fractional step pressure-coupling schemes.

class pseudo_time(path, service)#

Bases: TUIMenu

Pseudo-Time stability controls for multiphase flow.

Classes:

auto_dt_advanced_controls(path, service)

Set automatic time-stepping controls for better solution stability.

Methods:

false_time_step_linearization(*args, **kwargs)

Set false time-step linearization for added stability.

smoothed_density_stabilization_method(*args, ...)

Set smoothed density stabilization method.
class auto_dt_advanced_controls(path, service)#

Bases: TUIMenu

Set automatic time-stepping controls for better solution stability.

Methods:

dt_factor_max(*args, **kwargs)

Set maximum limit for increase in pseudo time step size.

dt_factor_min(*args, **kwargs)

Set minimum limit for reduction in pseudo time step size.

dt_init_limit(*args, **kwargs)

Set maximum value for pseudo time step size during first iteration.

dt_max(*args, **kwargs)

Set maximum value for pseudo time step size.

enable(*args, **kwargs)

Enable advanced automatic time stepping for better stability.

max_velocity_ratio(*args, **kwargs)

Set velocity ratio to freeze the time step size for better solution stability.
dt_factor_max(*args, **kwargs)#

Set maximum limit for increase in pseudo time step size.

dt_factor_min(*args, **kwargs)#

Set minimum limit for reduction in pseudo time step size.

dt_init_limit(*args, **kwargs)#

Set maximum value for pseudo time step size during first iteration.

dt_max(*args, **kwargs)#

Set maximum value for pseudo time step size.

enable(*args, **kwargs)#

Enable advanced automatic time stepping for better stability.

max_velocity_ratio(*args, **kwargs)#

Set velocity ratio to freeze the time step size for better solution stability.

false_time_step_linearization(*args, **kwargs)#

Set false time-step linearization for added stability.

smoothed_density_stabilization_method(*args, **kwargs)#

Set smoothed density stabilization method.

class boiling_parameters(path, service)#

Bases: TUIMenu

Enters the menu for the multiphase boiling model parameters.

Methods:

liquid_vof_factor(*args, **kwargs)

When enabled, considers liquid volume fraction effects by multiplying the heat transfer coefficients by the local liquid volume fraction.

thin_film(*args, **kwargs)

When enabled, includes multiphase boiling thin film effects using .
liquid_vof_factor(*args, **kwargs)#

When enabled, considers liquid volume fraction effects by multiplying the heat transfer coefficients by the local liquid volume fraction.

thin_film(*args, **kwargs)#

When enabled, includes multiphase boiling thin film effects using .

class compressible_flow(path, service)#

Bases: TUIMenu

Enters the compressible multiphase flow numerics menu.

Methods:

alternate_bc_formulation(*args, **kwargs)

Enables an alternative formulation for compressible phases at an inlet boundary.

enhanced_numerics(*args, **kwargs)

Enables an enhanced numerical treatment that provides better stability at startup and during calculation of compressible flows.
alternate_bc_formulation(*args, **kwargs)#

Enables an alternative formulation for compressible phases at an inlet boundary. This formulation calculates static temperature and pressure using an iterative method based on fundamental thermodynamic relations.

enhanced_numerics(*args, **kwargs)#

Enables an enhanced numerical treatment that provides better stability at startup and during calculation of compressible flows.

class default_controls(path, service)#

Bases: TUIMenu

Enters the default controls menu. This menu is available only for multiphase flows.

Methods:

recommended_defaults_for_existing_cases(...)

Applies the multiphase defaults (version 2020 R1) to the loaded case file.

revert_to_pre_r20_point_1_default_settings(...)

Revert to pre-R20.1 multiphase flow default settings.
recommended_defaults_for_existing_cases(*args, **kwargs)#

Applies the multiphase defaults (version 2020 R1) to the loaded case file.

revert_to_pre_r20_point_1_default_settings(*args, **kwargs)#

Revert to pre-R20.1 multiphase flow default settings.

class face_pressure_controls(path, service)#

Bases: TUIMenu

Enter the face pressure expert controls menu.

Methods:

face_pressure_options(*args, **kwargs)

Set face pressure options.
face_pressure_options(*args, **kwargs)#

Set face pressure options.

class heat_mass_transfer(path, service)#

Bases: TUIMenu

Enters the menu for the multiphase heat mass transfer parameters.

Methods:

alternative_energy_treatment(*args, **kwargs)

Enables the alternative treatment of the energy sources.

Classes:

area_density(path, service)

Enters the menu for the area density.

boiling(path, service)

Enters the menu for the advanced boiling options for the semi-mechanistic boiling model.

cavitation(path, service)

Enters the cavitation heat mass transfer menu.

evaporation_condensation(path, service)

Evaporation-condensation advanced options menu.
alternative_energy_treatment(*args, **kwargs)#

Enables the alternative treatment of the energy sources. For more information, see .

class area_density(path, service)#

Bases: TUIMenu

Enters the menu for the area density.

Methods:

ia_grad_sym(*args, **kwargs)

Enables/disables the interfacial area density Gradient-Symmetric model.

vof_min_seeding(*args, **kwargs)

Sets the minimum volume fraction for the area density and cavitation.
ia_grad_sym(*args, **kwargs)#

Enables/disables the interfacial area density Gradient-Symmetric model. For more information about this model, see .

vof_min_seeding(*args, **kwargs)#

Sets the minimum volume fraction for the area density and cavitation. This may be useful, for example, in cases when a species mass transfer model (such as the Symmetric model or Particle model) do not consider evaporation or condensation if the volume fraction of one of the phases is zero. The seeding allows for a phase change to occur in the fluid flow. The default value is 1e-6.

class boiling(path, service)#

Bases: TUIMenu

Enters the menu for the advanced boiling options for the semi-mechanistic boiling model.

Methods:

heat_flux_relaxation_factor(*args, **kwargs)

Sets the under-relaxation factor for boiling heat flux.

show_expert_options(*args, **kwargs)

Exposes the expert options for the semi-mechanistic boiling model.

two_resistance_boiling_framework(*args, **kwargs)

Enables/disables the two-resistance boiling framework to improve the robustness and accuracy of the solution of cases with multiple boiling mechanisms.
heat_flux_relaxation_factor(*args, **kwargs)#

Sets the under-relaxation factor for boiling heat flux. See for details.

show_expert_options(*args, **kwargs)#

Exposes the expert options for the semi-mechanistic boiling model. For more information about these options, see .

two_resistance_boiling_framework(*args, **kwargs)#

Enables/disables the two-resistance boiling framework to improve the robustness and accuracy of the solution of cases with multiple boiling mechanisms. For more information about this item, see .

class cavitation(path, service)#

Bases: TUIMenu

Enters the cavitation heat mass transfer menu.

Methods:

display_clipped_pressure(*args, **kwargs)

Clipped pressure is just used for the properties evaluation.

max_vapor_pressure_ratio(*args, **kwargs)

Sets the maximum limit on the vapor pressure after the turbulence and thermal correction.

min_vapor_pressure(*args, **kwargs)

Sets the minimum vapor pressure limit for the cavitation mass-transfer model.

schnerr_cond_coeff(*args, **kwargs)

Sets the condensation coefficient for the Schnerr-Sauer model ( in ).

schnerr_evap_coeff(*args, **kwargs)

Sets the evaporation coefficient for the Schnerr-Sauer model ( in ).

turbulent_diffusion(*args, **kwargs)

Enables/disables the turbulent diffusion treatment for a cavitating turbulent flow.
display_clipped_pressure(*args, **kwargs)#

Clipped pressure is just used for the properties evaluation. Mass Transfer Rate uses unclipped pressure.

max_vapor_pressure_ratio(*args, **kwargs)#

Sets the maximum limit on the vapor pressure after the turbulence and thermal correction. The default value is five times the vapor pressure, with consideration of turbulent and thermal effects for each cell and phase.

min_vapor_pressure(*args, **kwargs)#

Sets the minimum vapor pressure limit for the cavitation mass-transfer model. The default value is 1 Pa.

schnerr_cond_coeff(*args, **kwargs)#

Sets the condensation coefficient for the Schnerr-Sauer model ( in ). The default and recommended value of 0.2.

schnerr_evap_coeff(*args, **kwargs)#

Sets the evaporation coefficient for the Schnerr-Sauer model ( in ). The default and recommended value of 1.

turbulent_diffusion(*args, **kwargs)#

Enables/disables the turbulent diffusion treatment for a cavitating turbulent flow. See for details.

class evaporation_condensation(path, service)#

Bases: TUIMenu

Evaporation-condensation advanced options menu.

Methods:

ia_norm_min_limit(*args, **kwargs)

Minimum normalized area density below which mass transfer rate is set to zero.

max_rel_humidity(*args, **kwargs)

Maximum value of relative humidity to limit condensation rate.

vof_from_max_limit(*args, **kwargs)

Maximum volume fraction above which mass transfer rate is set to zero.

vof_from_min_limit(*args, **kwargs)

Minimum volume fraction below which mass transfer rate is set to zero.

vof_to_max_limit(*args, **kwargs)

Maximum volume fraction above which mass transfer rate is set to zero.

vof_to_min_limit(*args, **kwargs)

Minimum volume fraction below which mass transfer rate is set to zero.
ia_norm_min_limit(*args, **kwargs)#

Minimum normalized area density below which mass transfer rate is set to zero.

max_rel_humidity(*args, **kwargs)#

Maximum value of relative humidity to limit condensation rate.

vof_from_max_limit(*args, **kwargs)#

Maximum volume fraction above which mass transfer rate is set to zero.

vof_from_min_limit(*args, **kwargs)#

Minimum volume fraction below which mass transfer rate is set to zero.

vof_to_max_limit(*args, **kwargs)#

Maximum volume fraction above which mass transfer rate is set to zero.

vof_to_min_limit(*args, **kwargs)#

Minimum volume fraction below which mass transfer rate is set to zero.

class porous_media(path, service)#

Bases: TUIMenu

Enters the porous media numerics menu.

Methods:

capillary_pressure_as_diffusion(*args, **kwargs)

Model capillary pressure as diffusion.

relative_permeability(*args, **kwargs)

Allows you to fix the saturation (volume fraction) of the phase at its user-specified residual saturation value.
capillary_pressure_as_diffusion(*args, **kwargs)#

Model capillary pressure as diffusion.

relative_permeability(*args, **kwargs)#

Allows you to fix the saturation (volume fraction) of the phase at its user-specified residual saturation value.

class solution_stabilization(path, service)#

Bases: TUIMenu

Enters the solution-stabilization numerics menu. This item is available only for the VOF model.

Classes:

additional_stabilization_controls(path, service)

Enters the menu for additional advanced stability controls.

velocity_limiting_treatment(path, service)

Enters the menu for the velocity-limiting-treatment.

Methods:

execute_additional_stability_controls(*args, ...)

When enabled, uses additional controls for improved solution stability.

execute_advanced_stabilization(*args, **kwargs)

When enabled, modifies solver settings for improved solution stability.

execute_settings_optimization(*args, **kwargs)

Execute optimized settings for VOF.
class additional_stabilization_controls(path, service)#

Bases: TUIMenu

Enters the menu for additional advanced stability controls.

Methods:

blended_compressive_scheme(*args, **kwargs)

Enables/disables the blended compressive discretization scheme.

pseudo_time_stabilization(*args, **kwargs)

Pseudo-Time Momentum stabilization and False Time Step Linearization methods for VOF.
blended_compressive_scheme(*args, **kwargs)#

Enables/disables the blended compressive discretization scheme.

pseudo_time_stabilization(*args, **kwargs)#

Pseudo-Time Momentum stabilization and False Time Step Linearization methods for VOF.

execute_additional_stability_controls(*args, **kwargs)#

When enabled, uses additional controls for improved solution stability.

execute_advanced_stabilization(*args, **kwargs)#

When enabled, modifies solver settings for improved solution stability.

execute_settings_optimization(*args, **kwargs)#

Execute optimized settings for VOF.

class velocity_limiting_treatment(path, service)#

Bases: TUIMenu

Enters the menu for the velocity-limiting-treatment.

Methods:

enable_velocity_limiting(*args, **kwargs)

Enables/disables the velocity limiting treatment.

set_damping_strength(*args, **kwargs)

Enter damping strength.

set_damping_strengths(*args, **kwargs)

Set phase based damping strength.

set_velocity_and_vof_cutoffs(*args, **kwargs)

Set phase based velocity limiting controls.

set_velocity_cutoff(*args, **kwargs)

Specifies the maximum velocity magnitude.

verbosity(*args, **kwargs)

When enabled, the solver prints the number of velocity limited cells at each iteration.
enable_velocity_limiting(*args, **kwargs)#

Enables/disables the velocity limiting treatment.

set_damping_strength(*args, **kwargs)#

Enter damping strength.

set_damping_strengths(*args, **kwargs)#

Set phase based damping strength.

set_velocity_and_vof_cutoffs(*args, **kwargs)#

Set phase based velocity limiting controls.

set_velocity_cutoff(*args, **kwargs)#

Specifies the maximum velocity magnitude.

verbosity(*args, **kwargs)#

When enabled, the solver prints the number of velocity limited cells at each iteration.

class viscous_flow(path, service)#

Bases: TUIMenu

Enters the viscous multiphase flow numerics menu.

Methods:

interfacial_artificial_viscosity(*args, **kwargs)

Interfacial artifical viscosity controls.

turb_visc_based_damping(*args, **kwargs)

Turbulence viscosity based damping controls.

viscosity_averaging(*args, **kwargs)

Forces harmonic averaging of cell viscosities to calculate face viscosity used in momentum equation.
interfacial_artificial_viscosity(*args, **kwargs)#

Interfacial artifical viscosity controls.

turb_visc_based_damping(*args, **kwargs)#

Turbulence viscosity based damping controls.

viscosity_averaging(*args, **kwargs)#

Forces harmonic averaging of cell viscosities to calculate face viscosity used in momentum equation. This can improve convergence for highly viscous flow applications (the VOF model only).