PIMPLE

Solves the transient Navier-Stokes equations using the PIMPLE algorithm and linear finite volume variables.

Overview

This transient executioner is based on the algorithm discussed in Greenshields and Weller (2022). It is a combination of SIMPLE and the PISO (Pressure-Implicit with Splitting of Operators) algorithm introduced by Issa (1986).

In PISO, the user iterates between the source term in the pressure equation and the corrected pressure and velocity fields without assembling the momentum system again. With the notation already used in SIMPLE, the PISO iteration is the following:

Take a velocity guess and compute $var element = document.getElementById("moose-equation-e88c61cc-7902-4678-adff-1fe347f54ff4");katex.render("H(u^n)", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ which is the offdiagonals of the momentum system matrix multiplied by the current guess minus the right hand side of the momentum matrix. Note that the face flux is computed using a different quess so this operation is just a matrix-vector multiplication and a vector-vector addition.
Use $var element = document.getElementById("moose-equation-16f6431d-b569-4538-8725-ba13d8a90eee");katex.render("H(u^n)", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ and the diagonal of the momentum matrix $var element = document.getElementById("moose-equation-8b02e125-8912-4a47-ad8e-d56b702f1130");katex.render("A", element, {displayMode:false,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$ to solve the pressure equation:
$var element = document.getElementById("moose-equation-dd45a58f-046a-412e-9909-a1e1781e7964");katex.render("\\nabla \\cdot \\left(A^{-1}H(\\vec{u}^{n})\\right) = -\\nabla \\cdot \\left(A^{-1}\\nabla p^n\\right).", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$
The pressure solution might have to be relaxed in this iteration:
$var element = document.getElementById("moose-equation-23abe10d-07bb-4b4c-9e07-14820bf13fb6");katex.render("p^{n,*} = p^n + \\lambda_p (p^{n}-p^{n-1}).", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$
Once the pressure solution is obtained, update the velocity to the next guess:
$(1)var element = document.getElementById("moose-equation-eaa2ce9c-e027-4e35-9f00-5747b0e74e6a");katex.render("\\vec{u}^{n+1} = - A^{-1}H(\\vec{u}^{n}) -A^{-1}\\nabla p^{n,*},", element, {displayMode:true,throwOnError:false,macros:{"\\eqc":"\\,,","\\eqp":"\\,.","\\pd":"\\frac{\\partial #1}{\\partial #2}","\\pr":"\\left(#1\\right)","\\ddt":"\\frac{d #1}{d t}"}});$
and return to (1) until the maximum number of iterations is reached which can be set using the "num_piso_iterations" parameter.

Example Input Syntax

The problem setup is exactly the same as discussed for SIMPLE, only the executioner block is different:

[Executioner<<<{"href": "../../syntax/Executioner/index.html"}>>>]
  type = PIMPLE
  momentum_l_abs_tol = 1e-12
  pressure_l_abs_tol = 1e-12
  energy_l_abs_tol = 1e-12
  momentum_l_tol = 1e-12
  pressure_l_tol = 1e-12
  energy_l_tol = 1e-12
  rhie_chow_user_object = 'rc'
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  energy_system = 'energy_system'
  momentum_equation_relaxation = 0.8
  pressure_variable_relaxation = 0.3
  energy_equation_relaxation = 0.9
  num_iterations = 100
  pressure_absolute_tolerance = 1e-11
  momentum_absolute_tolerance = 1e-11
  energy_absolute_tolerance = 1e-11
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  energy_petsc_options_iname = '-pc_type -pc_hypre_type'
  energy_petsc_options_value = 'hypre boomeramg'
  print_fields = false
  continue_on_max_its = true
  dt = 0.01
  num_steps = 6
  num_piso_iterations = 0
[]

Input Parameters

rhie_chow_user_objectThe rhie-chow user-object
C++ Type:UserObjectName
Controllable:No
Description:The rhie-chow user-object

Required Parameters

continue_on_max_itsFalseIf solve should continue if maximum number of iterations is hit.
Default:False
C++ Type:bool
Controllable:No
Description:If solve should continue if maximum number of iterations is hit.
dt1The timestep size between solves
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The timestep size between solves
end_time1e+30The end time of the simulation
Default:1e+30
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The end time of the simulation
energy_systemThe solver system for the energy equation.
C++ Type:SolverSystemName
Controllable:No
Description:The solver system for the energy equation.
error_on_dtminTrueThrow error when timestep is less than dtmin instead of just aborting solve.
Default:True
C++ Type:bool
Controllable:No
Description:Throw error when timestep is less than dtmin instead of just aborting solve.
normalize_solution_diff_norm_by_dtTrueWhether to divide the solution difference norm by dt. If taking 'small' time steps you probably want this to be true. If taking very 'large' timesteps in an attempt to *reach* a steady-state, you probably want this parameter to be false.
Default:True
C++ Type:bool
Controllable:No
Description:Whether to divide the solution difference norm by dt. If taking 'small' time steps you probably want this to be true. If taking very 'large' timesteps in an attempt to *reach* a steady-state, you probably want this parameter to be false.
num_iterations1000The number of momentum-pressure-(other fields) iterations needed.
Default:1000
C++ Type:unsigned int
Controllable:No
Description:The number of momentum-pressure-(other fields) iterations needed.
num_piso_iterations0The number of PISO iterations without recomputing the momentum matrix.
Default:0
C++ Type:unsigned int
Controllable:No
Description:The number of PISO iterations without recomputing the momentum matrix.
num_steps4294967295The number of timesteps in a transient run
Default:4294967295
C++ Type:unsigned int
Controllable:No
Description:The number of timesteps in a transient run
print_fieldsFalseUse this to print the coupling and solution fields and matrices throughout the iteration.
Default:False
C++ Type:bool
Controllable:No
Description:Use this to print the coupling and solution fields and matrices throughout the iteration.
reset_dtFalseUse when restarting a calculation to force a change in dt.
Default:False
C++ Type:bool
Controllable:No
Description:Use when restarting a calculation to force a change in dt.
schemeimplicit-eulerTime integration scheme used.
Default:implicit-euler
C++ Type:MooseEnum
Options:implicit-euler, explicit-euler, crank-nicolson, bdf2, explicit-midpoint, dirk, explicit-tvd-rk-2, newmark-beta
Controllable:No
Description:Time integration scheme used.
solid_energy_systemThe solver system for the solid energy equation.
C++ Type:SolverSystemName
Controllable:No
Description:The solver system for the solid energy equation.
verboseFalseSet to true to print additional information
Default:False
C++ Type:bool
Controllable:No
Description:Set to true to print additional information

Optional Parameters

abort_on_solve_failFalseabort if solve not converged rather than cut timestep
Default:False
C++ Type:bool
Controllable:No
Description:abort if solve not converged rather than cut timestep
control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
dtmax1e+30The maximum timestep size in an adaptive run
Default:1e+30
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The maximum timestep size in an adaptive run
dtmin1e-12The minimum timestep size in an adaptive run
Default:1e-12
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The minimum timestep size in an adaptive run
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:No
Description:Set the enabled status of the MooseObject.
n_startup_steps0The number of timesteps during startup
Default:0
C++ Type:int
Controllable:No
Description:The number of timesteps during startup
outputsVector of output names where you would like to restrict the output of variables(s) associated with this object
C++ Type:std::vector<OutputName>
Controllable:No
Description:Vector of output names where you would like to restrict the output of variables(s) associated with this object
start_time0The start time of the simulation
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The start time of the simulation
timestep_tolerance1e-12the tolerance setting for final timestep size and sync times
Default:1e-12
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:the tolerance setting for final timestep size and sync times
use_multiapp_dtFalseIf true then the dt for the simulation will be chosen by the MultiApps. If false (the default) then the minimum over the master dt and the MultiApps is used
Default:False
C++ Type:bool
Controllable:No
Description:If true then the dt for the simulation will be chosen by the MultiApps. If false (the default) then the minimum over the master dt and the MultiApps is used

Advanced Parameters

accept_on_max_fixed_point_iterationFalseTrue to treat reaching the maximum number of fixed point iterations as converged.
Default:False
C++ Type:bool
Controllable:No
Description:True to treat reaching the maximum number of fixed point iterations as converged.
auto_advanceFalseWhether to automatically advance sub-applications regardless of whether their solve converges, for transient executioners only.
Default:False
C++ Type:bool
Controllable:No
Description:Whether to automatically advance sub-applications regardless of whether their solve converges, for transient executioners only.
custom_abs_tol1e-50The absolute nonlinear residual to shoot for during fixed point iterations. This check is performed based on postprocessor defined by the custom_pp residual.
Default:1e-50
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute nonlinear residual to shoot for during fixed point iterations. This check is performed based on postprocessor defined by the custom_pp residual.
custom_ppPostprocessor for custom fixed point convergence check.
C++ Type:PostprocessorName
Unit:(no unit assumed)
Controllable:No
Description:Postprocessor for custom fixed point convergence check.
custom_rel_tol1e-08The relative nonlinear residual drop to shoot for during fixed point iterations. This check is performed based on the postprocessor defined by custom_pp residual.
Default:1e-08
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relative nonlinear residual drop to shoot for during fixed point iterations. This check is performed based on the postprocessor defined by custom_pp residual.
direct_pp_valueFalseTrue to use direct postprocessor value (scaled by value on first iteration). False (default) to use difference in postprocessor value between fixed point iterations.
Default:False
C++ Type:bool
Controllable:No
Description:True to use direct postprocessor value (scaled by value on first iteration). False (default) to use difference in postprocessor value between fixed point iterations.
disable_fixed_point_residual_norm_checkFalseDisable the residual norm evaluation thus the three parameters fixed_point_rel_tol, fixed_point_abs_tol and fixed_point_force_norms.
Default:False
C++ Type:bool
Controllable:No
Description:Disable the residual norm evaluation thus the three parameters fixed_point_rel_tol, fixed_point_abs_tol and fixed_point_force_norms.
fixed_point_abs_tol1e-50The absolute nonlinear residual to shoot for during fixed point iterations. This check is performed based on the main app's nonlinear residual.
Default:1e-50
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute nonlinear residual to shoot for during fixed point iterations. This check is performed based on the main app's nonlinear residual.
fixed_point_algorithmpicardThe fixed point algorithm to converge the sequence of problems.
Default:picard
C++ Type:MooseEnum
Options:picard, secant, steffensen
Controllable:No
Description:The fixed point algorithm to converge the sequence of problems.
fixed_point_force_normsFalseForce the evaluation of both the TIMESTEP_BEGIN and TIMESTEP_END norms regardless of the existence of active MultiApps with those execute_on flags, default: false.
Default:False
C++ Type:bool
Controllable:No
Description:Force the evaluation of both the TIMESTEP_BEGIN and TIMESTEP_END norms regardless of the existence of active MultiApps with those execute_on flags, default: false.
fixed_point_max_its1Specifies the maximum number of fixed point iterations.
Default:1
C++ Type:unsigned int
Controllable:No
Description:Specifies the maximum number of fixed point iterations.
fixed_point_min_its1Specifies the minimum number of fixed point iterations.
Default:1
C++ Type:unsigned int
Controllable:No
Description:Specifies the minimum number of fixed point iterations.
fixed_point_rel_tol1e-08The relative nonlinear residual drop to shoot for during fixed point iterations. This check is performed based on the main app's nonlinear residual.
Default:1e-08
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relative nonlinear residual drop to shoot for during fixed point iterations. This check is performed based on the main app's nonlinear residual.
multiapp_fixed_point_convergenceName of the Convergence object to use to assess convergence of the MultiApp fixed point solve. If not provided, a default Convergence will be constructed internally from the executioner parameters.
C++ Type:ConvergenceName
Controllable:No
Description:Name of the Convergence object to use to assess convergence of the MultiApp fixed point solve. If not provided, a default Convergence will be constructed internally from the executioner parameters.
relaxation_factor1Fraction of newly computed value to keep.Set between 0 and 2.
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Fraction of newly computed value to keep.Set between 0 and 2.
transformed_postprocessorsList of main app postprocessors to transform during fixed point iterations
C++ Type:std::vector<PostprocessorName>
Unit:(no unit assumed)
Controllable:No
Description:List of main app postprocessors to transform during fixed point iterations
transformed_variablesList of main app variables to transform during fixed point iterations
C++ Type:std::vector<std::string>
Controllable:No
Description:List of main app variables to transform during fixed point iterations

Fixed Point Iterations Parameters

active_scalar_absolute_toleranceThe absolute tolerance(s) on the normalized residual(s) of the active scalar equation(s).
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance(s) on the normalized residual(s) of the active scalar equation(s).
active_scalar_equation_relaxationThe relaxation which should be used for the active scalar equations. (=1 for no relaxation, diagonal dominance will still be enforced)
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:The relaxation which should be used for the active scalar equations. (=1 for no relaxation, diagonal dominance will still be enforced)
active_scalar_l_abs_tol1e-10The absolute tolerance on the normalized residual in the linear solver of the active scalar equation(s).
Default:1e-10
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual in the linear solver of the active scalar equation(s).
active_scalar_l_max_its10000The maximum allowed iterations in the linear solver of the turbulence equation.
Default:10000
C++ Type:unsigned int
Controllable:No
Description:The maximum allowed iterations in the linear solver of the turbulence equation.
active_scalar_l_tol1e-05The relative tolerance on the normalized residual in the linear solver of the active scalar equation(s).
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relative tolerance on the normalized residual in the linear solver of the active scalar equation(s).
active_scalar_petsc_optionsSingleton PETSc options for the active scalar equation(s)
C++ Type:MultiMooseEnum
Options:-dm_moose_print_embedding, -dm_view, -KSP_CONVERGED_REASON, -KSP_GMRES_MODIFIEDGRAMSCHMIDT, -KSP_MONITOR, -KSP_MONITOR_SNES_LG, -SNES_KSP_EW, -KSP_SNES_EW, -SNES_CONVERGED_REASON, -SNES_KSP, -SNES_LINESEARCH_MONITOR, -SNES_MF, -SNES_MF_OPERATOR, -SNES_MONITOR, -SNES_TEST_DISPLAY, -SNES_VIEW, -SNES_MONITOR_CANCEL
Controllable:No
Description:Singleton PETSc options for the active scalar equation(s)
active_scalar_petsc_options_inameNames of PETSc name/value pairs for the active scalar equation(s)
C++ Type:MultiMooseEnum
Options:-mat_fd_coloring_err, -mat_fd_type, -mat_mffd_type, -pc_asm_overlap, -pc_factor_levels, -pc_factor_mat_ordering_type, -pc_hypre_boomeramg_grid_sweeps_all, -pc_hypre_boomeramg_max_iter, -pc_hypre_boomeramg_strong_threshold, -pc_hypre_type, -pc_type, -sub_pc_type, -KSP_ATOL, -KSP_GMRES_RESTART, -KSP_MAX_IT, -KSP_PC_SIDE, -KSP_RTOL, -KSP_TYPE, -SUB_KSP_TYPE, -SNES_ATOL, -SNES_LINESEARCH_TYPE, -SNES_LS, -SNES_MAX_IT, -SNES_RTOL, -SNES_DIVERGENCE_TOLERANCE, -SNES_TYPE
Controllable:No
Description:Names of PETSc name/value pairs for the active scalar equation(s)
active_scalar_petsc_options_valueValues of PETSc name/value pairs (must correspond with "petsc_options_iname" for the active scalar equation(s)
C++ Type:std::vector<std::string>
Controllable:No
Description:Values of PETSc name/value pairs (must correspond with "petsc_options_iname" for the active scalar equation(s)
active_scalar_systemsThe solver system for each active scalar advection equation.
C++ Type:std::vector<SolverSystemName>
Controllable:No
Description:The solver system for each active scalar advection equation.

Active Scalars Equations Parameters

check_auxFalseWhether to check the auxiliary system for convergence to steady-state. If false, then the nonlinear system is used.
Default:False
C++ Type:bool
Controllable:No
Description:Whether to check the auxiliary system for convergence to steady-state. If false, then the nonlinear system is used.
steady_state_detectionFalseWhether or not to check for steady state conditions
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to check for steady state conditions
steady_state_start_time0Minimum amount of time to run before checking for steady state conditions.
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Minimum amount of time to run before checking for steady state conditions.
steady_state_tolerance1e-08Whenever the relative residual changes by less than this the solution will be considered to be at steady state.
Default:1e-08
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Whenever the relative residual changes by less than this the solution will be considered to be at steady state.

Steady State Detection Parameters

energy_absolute_tolerance1e-05The absolute tolerance on the normalized residual of the energy equation.
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual of the energy equation.
energy_equation_relaxation1The relaxation which should be used for the energy equation. (=1 for no relaxation, diagonal dominance will still be enforced)
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relaxation which should be used for the energy equation. (=1 for no relaxation, diagonal dominance will still be enforced)
energy_l_abs_tol1e-10The absolute tolerance on the normalized residual in the linear solver of the energy equation.
Default:1e-10
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual in the linear solver of the energy equation.
energy_l_max_its10000The maximum allowed iterations in the linear solver of the energy equation.
Default:10000
C++ Type:unsigned int
Controllable:No
Description:The maximum allowed iterations in the linear solver of the energy equation.
energy_l_tol1e-05The relative tolerance on the normalized residual in the linear solver of the energy equation.
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relative tolerance on the normalized residual in the linear solver of the energy equation.
energy_petsc_optionsSingleton PETSc options for the energy equation
C++ Type:MultiMooseEnum
Options:-dm_moose_print_embedding, -dm_view, -KSP_CONVERGED_REASON, -KSP_GMRES_MODIFIEDGRAMSCHMIDT, -KSP_MONITOR, -KSP_MONITOR_SNES_LG, -SNES_KSP_EW, -KSP_SNES_EW, -SNES_CONVERGED_REASON, -SNES_KSP, -SNES_LINESEARCH_MONITOR, -SNES_MF, -SNES_MF_OPERATOR, -SNES_MONITOR, -SNES_TEST_DISPLAY, -SNES_VIEW, -SNES_MONITOR_CANCEL
Controllable:No
Description:Singleton PETSc options for the energy equation
energy_petsc_options_inameNames of PETSc name/value pairs for the energy equation
C++ Type:MultiMooseEnum
Options:-mat_fd_coloring_err, -mat_fd_type, -mat_mffd_type, -pc_asm_overlap, -pc_factor_levels, -pc_factor_mat_ordering_type, -pc_hypre_boomeramg_grid_sweeps_all, -pc_hypre_boomeramg_max_iter, -pc_hypre_boomeramg_strong_threshold, -pc_hypre_type, -pc_type, -sub_pc_type, -KSP_ATOL, -KSP_GMRES_RESTART, -KSP_MAX_IT, -KSP_PC_SIDE, -KSP_RTOL, -KSP_TYPE, -SUB_KSP_TYPE, -SNES_ATOL, -SNES_LINESEARCH_TYPE, -SNES_LS, -SNES_MAX_IT, -SNES_RTOL, -SNES_DIVERGENCE_TOLERANCE, -SNES_TYPE
Controllable:No
Description:Names of PETSc name/value pairs for the energy equation
energy_petsc_options_valueValues of PETSc name/value pairs (must correspond with "petsc_options_iname" for the energy equation
C++ Type:std::vector<std::string>
Controllable:No
Description:Values of PETSc name/value pairs (must correspond with "petsc_options_iname" for the energy equation

Energy Equation Parameters

max_xfem_update4294967295Maximum number of times to update XFEM crack topology in a step due to evolving cracks
Default:4294967295
C++ Type:unsigned int
Controllable:No
Description:Maximum number of times to update XFEM crack topology in a step due to evolving cracks
update_xfem_at_timestep_beginFalseShould XFEM update the mesh at the beginning of the timestep
Default:False
C++ Type:bool
Controllable:No
Description:Should XFEM update the mesh at the beginning of the timestep

Xfem Fixed Point Iterations Parameters

momentum_absolute_tolerance1e-05The absolute tolerance on the normalized residual of the momentum equation.
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual of the momentum equation.
momentum_equation_relaxation1The relaxation which should be used for the momentum equation. (=1 for no relaxation, diagonal dominance will still be enforced)
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relaxation which should be used for the momentum equation. (=1 for no relaxation, diagonal dominance will still be enforced)
momentum_l_abs_tol1e-50The absolute tolerance on the normalized residual in the linear solver of the momentum equation.
Default:1e-50
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual in the linear solver of the momentum equation.
momentum_l_max_its10000The maximum allowed iterations in the linear solver of the momentum equation.
Default:10000
C++ Type:unsigned int
Controllable:No
Description:The maximum allowed iterations in the linear solver of the momentum equation.
momentum_l_tol1e-05The relative tolerance on the normalized residual in the linear solver of the momentum equation.
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relative tolerance on the normalized residual in the linear solver of the momentum equation.
momentum_petsc_optionsSingleton PETSc options for the momentum equation
C++ Type:MultiMooseEnum
Options:-dm_moose_print_embedding, -dm_view, -KSP_CONVERGED_REASON, -KSP_GMRES_MODIFIEDGRAMSCHMIDT, -KSP_MONITOR, -KSP_MONITOR_SNES_LG, -SNES_KSP_EW, -KSP_SNES_EW, -SNES_CONVERGED_REASON, -SNES_KSP, -SNES_LINESEARCH_MONITOR, -SNES_MF, -SNES_MF_OPERATOR, -SNES_MONITOR, -SNES_TEST_DISPLAY, -SNES_VIEW, -SNES_MONITOR_CANCEL
Controllable:No
Description:Singleton PETSc options for the momentum equation
momentum_petsc_options_inameNames of PETSc name/value pairs for the momentum equation
C++ Type:MultiMooseEnum
Options:-mat_fd_coloring_err, -mat_fd_type, -mat_mffd_type, -pc_asm_overlap, -pc_factor_levels, -pc_factor_mat_ordering_type, -pc_hypre_boomeramg_grid_sweeps_all, -pc_hypre_boomeramg_max_iter, -pc_hypre_boomeramg_strong_threshold, -pc_hypre_type, -pc_type, -sub_pc_type, -KSP_ATOL, -KSP_GMRES_RESTART, -KSP_MAX_IT, -KSP_PC_SIDE, -KSP_RTOL, -KSP_TYPE, -SUB_KSP_TYPE, -SNES_ATOL, -SNES_LINESEARCH_TYPE, -SNES_LS, -SNES_MAX_IT, -SNES_RTOL, -SNES_DIVERGENCE_TOLERANCE, -SNES_TYPE
Controllable:No
Description:Names of PETSc name/value pairs for the momentum equation
momentum_petsc_options_valueValues of PETSc name/value pairs (must correspond with "petsc_options_iname" for the momentum equation
C++ Type:std::vector<std::string>
Controllable:No
Description:Values of PETSc name/value pairs (must correspond with "petsc_options_iname" for the momentum equation
momentum_systemsThe solver system(s) for the momentum equation(s).
C++ Type:std::vector<SolverSystemName>
Controllable:No
Description:The solver system(s) for the momentum equation(s).

Momentum Equation Parameters

passive_scalar_absolute_toleranceThe absolute tolerance(s) on the normalized residual(s) of the passive scalar equation(s).
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance(s) on the normalized residual(s) of the passive scalar equation(s).
passive_scalar_equation_relaxationThe relaxation which should be used for the passive scalar equations. (=1 for no relaxation, diagonal dominance will still be enforced)
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:The relaxation which should be used for the passive scalar equations. (=1 for no relaxation, diagonal dominance will still be enforced)
passive_scalar_l_abs_tol1e-10The absolute tolerance on the normalized residual in the linear solver of the passive scalar equation(s).
Default:1e-10
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual in the linear solver of the passive scalar equation(s).
passive_scalar_l_max_its10000The maximum allowed iterations in the linear solver of the turbulence equation.
Default:10000
C++ Type:unsigned int
Controllable:No
Description:The maximum allowed iterations in the linear solver of the turbulence equation.
passive_scalar_l_tol1e-05The relative tolerance on the normalized residual in the linear solver of the passive scalar equation(s).
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relative tolerance on the normalized residual in the linear solver of the passive scalar equation(s).
passive_scalar_petsc_optionsSingleton PETSc options for the passive scalar equation(s)
C++ Type:MultiMooseEnum
Options:-dm_moose_print_embedding, -dm_view, -KSP_CONVERGED_REASON, -KSP_GMRES_MODIFIEDGRAMSCHMIDT, -KSP_MONITOR, -KSP_MONITOR_SNES_LG, -SNES_KSP_EW, -KSP_SNES_EW, -SNES_CONVERGED_REASON, -SNES_KSP, -SNES_LINESEARCH_MONITOR, -SNES_MF, -SNES_MF_OPERATOR, -SNES_MONITOR, -SNES_TEST_DISPLAY, -SNES_VIEW, -SNES_MONITOR_CANCEL
Controllable:No
Description:Singleton PETSc options for the passive scalar equation(s)
passive_scalar_petsc_options_inameNames of PETSc name/value pairs for the passive scalar equation(s)
C++ Type:MultiMooseEnum
Options:-mat_fd_coloring_err, -mat_fd_type, -mat_mffd_type, -pc_asm_overlap, -pc_factor_levels, -pc_factor_mat_ordering_type, -pc_hypre_boomeramg_grid_sweeps_all, -pc_hypre_boomeramg_max_iter, -pc_hypre_boomeramg_strong_threshold, -pc_hypre_type, -pc_type, -sub_pc_type, -KSP_ATOL, -KSP_GMRES_RESTART, -KSP_MAX_IT, -KSP_PC_SIDE, -KSP_RTOL, -KSP_TYPE, -SUB_KSP_TYPE, -SNES_ATOL, -SNES_LINESEARCH_TYPE, -SNES_LS, -SNES_MAX_IT, -SNES_RTOL, -SNES_DIVERGENCE_TOLERANCE, -SNES_TYPE
Controllable:No
Description:Names of PETSc name/value pairs for the passive scalar equation(s)
passive_scalar_petsc_options_valueValues of PETSc name/value pairs (must correspond with "petsc_options_iname" for the passive scalar equation(s)
C++ Type:std::vector<std::string>
Controllable:No
Description:Values of PETSc name/value pairs (must correspond with "petsc_options_iname" for the passive scalar equation(s)
passive_scalar_systemsThe solver system for each scalar advection equation.
C++ Type:std::vector<SolverSystemName>
Controllable:No
Description:The solver system for each scalar advection equation.

Passive_Scalar Equation Parameters

pin_pressureFalseIf the pressure field needs to be pinned at a point.
Default:False
C++ Type:bool
Controllable:No
Description:If the pressure field needs to be pinned at a point.
pressure_pin_pointThe point where the pressure needs to be pinned.
C++ Type:libMesh::Point
Controllable:No
Description:The point where the pressure needs to be pinned.
pressure_pin_value0The value which needs to be enforced for the pressure.
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The value which needs to be enforced for the pressure.

Pressure Pin Parameters

pressure_absolute_tolerance1e-05The absolute tolerance on the normalized residual of the pressure equation.
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual of the pressure equation.
pressure_l_abs_tol1e-10The absolute tolerance on the normalized residual in the linear solver of the pressure equation.
Default:1e-10
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual in the linear solver of the pressure equation.
pressure_l_max_its10000The maximum allowed iterations in the linear solver of the pressure equation.
Default:10000
C++ Type:unsigned int
Controllable:No
Description:The maximum allowed iterations in the linear solver of the pressure equation.
pressure_l_tol1e-05The relative tolerance on the normalized residual in the linear solver of the pressure equation.
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relative tolerance on the normalized residual in the linear solver of the pressure equation.
pressure_petsc_optionsSingleton PETSc options for the pressure equation
C++ Type:MultiMooseEnum
Options:-dm_moose_print_embedding, -dm_view, -KSP_CONVERGED_REASON, -KSP_GMRES_MODIFIEDGRAMSCHMIDT, -KSP_MONITOR, -KSP_MONITOR_SNES_LG, -SNES_KSP_EW, -KSP_SNES_EW, -SNES_CONVERGED_REASON, -SNES_KSP, -SNES_LINESEARCH_MONITOR, -SNES_MF, -SNES_MF_OPERATOR, -SNES_MONITOR, -SNES_TEST_DISPLAY, -SNES_VIEW, -SNES_MONITOR_CANCEL
Controllable:No
Description:Singleton PETSc options for the pressure equation
pressure_petsc_options_inameNames of PETSc name/value pairs for the pressure equation
C++ Type:MultiMooseEnum
Options:-mat_fd_coloring_err, -mat_fd_type, -mat_mffd_type, -pc_asm_overlap, -pc_factor_levels, -pc_factor_mat_ordering_type, -pc_hypre_boomeramg_grid_sweeps_all, -pc_hypre_boomeramg_max_iter, -pc_hypre_boomeramg_strong_threshold, -pc_hypre_type, -pc_type, -sub_pc_type, -KSP_ATOL, -KSP_GMRES_RESTART, -KSP_MAX_IT, -KSP_PC_SIDE, -KSP_RTOL, -KSP_TYPE, -SUB_KSP_TYPE, -SNES_ATOL, -SNES_LINESEARCH_TYPE, -SNES_LS, -SNES_MAX_IT, -SNES_RTOL, -SNES_DIVERGENCE_TOLERANCE, -SNES_TYPE
Controllable:No
Description:Names of PETSc name/value pairs for the pressure equation
pressure_petsc_options_valueValues of PETSc name/value pairs (must correspond with "petsc_options_iname" for the pressure equation
C++ Type:std::vector<std::string>
Controllable:No
Description:Values of PETSc name/value pairs (must correspond with "petsc_options_iname" for the pressure equation
pressure_systemThe solver system for the pressure equation.
C++ Type:SolverSystemName
Controllable:No
Description:The solver system for the pressure equation.
pressure_variable_relaxation1The relaxation which should be used for the pressure variable (=1 for no relaxation).
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relaxation which should be used for the pressure variable (=1 for no relaxation).

Pressure Equation Parameters

Restart Parameters

solid_energy_absolute_tolerance1e-05The absolute tolerance on the normalized residual of the solid energy equation.
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual of the solid energy equation.
solid_energy_l_abs_tol1e-10The absolute tolerance on the normalized residual in the linear solver of the solid energy equation.
Default:1e-10
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The absolute tolerance on the normalized residual in the linear solver of the solid energy equation.
solid_energy_l_max_its10000The maximum allowed iterations in the linear solver of the solid energy equation.
Default:10000
C++ Type:unsigned int
Controllable:No
Description:The maximum allowed iterations in the linear solver of the solid energy equation.
solid_energy_l_tol1e-05The relative tolerance on the normalized residual in the linear solver of the solid energy equation.
Default:1e-05
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The relative tolerance on the normalized residual in the linear solver of the solid energy equation.
solid_energy_petsc_optionsSingleton PETSc options for the solid energy equation
C++ Type:MultiMooseEnum
Options:-dm_moose_print_embedding, -dm_view, -KSP_CONVERGED_REASON, -KSP_GMRES_MODIFIEDGRAMSCHMIDT, -KSP_MONITOR, -KSP_MONITOR_SNES_LG, -SNES_KSP_EW, -KSP_SNES_EW, -SNES_CONVERGED_REASON, -SNES_KSP, -SNES_LINESEARCH_MONITOR, -SNES_MF, -SNES_MF_OPERATOR, -SNES_MONITOR, -SNES_TEST_DISPLAY, -SNES_VIEW, -SNES_MONITOR_CANCEL
Controllable:No
Description:Singleton PETSc options for the solid energy equation
solid_energy_petsc_options_inameNames of PETSc name/value pairs for the solid energy equation
C++ Type:MultiMooseEnum
Options:-mat_fd_coloring_err, -mat_fd_type, -mat_mffd_type, -pc_asm_overlap, -pc_factor_levels, -pc_factor_mat_ordering_type, -pc_hypre_boomeramg_grid_sweeps_all, -pc_hypre_boomeramg_max_iter, -pc_hypre_boomeramg_strong_threshold, -pc_hypre_type, -pc_type, -sub_pc_type, -KSP_ATOL, -KSP_GMRES_RESTART, -KSP_MAX_IT, -KSP_PC_SIDE, -KSP_RTOL, -KSP_TYPE, -SUB_KSP_TYPE, -SNES_ATOL, -SNES_LINESEARCH_TYPE, -SNES_LS, -SNES_MAX_IT, -SNES_RTOL, -SNES_DIVERGENCE_TOLERANCE, -SNES_TYPE
Controllable:No
Description:Names of PETSc name/value pairs for the solid energy equation
solid_energy_petsc_options_valueValues of PETSc name/value pairs (must correspond with "petsc_options_iname" for the solid energy equation
C++ Type:std::vector<std::string>
Controllable:No
Description:Values of PETSc name/value pairs (must correspond with "petsc_options_iname" for the solid energy equation

Solid Energy Equation Parameters

time_period_endsThe end times of time periods
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:The end times of time periods
time_period_startsThe start times of time periods
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:The start times of time periods
time_periodsThe names of periods
C++ Type:std::vector<std::string>
Controllable:No
Description:The names of periods

Time Periods Parameters

Input Files

(modules/navier_stokes/examples/flow-over-circle/flow_over_circle_linearfv.i)
(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/1d-scalar/channel-transient-physics.i)
(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/2d/2d-boussinesq-transient-physics.i)
(modules/navier_stokes/test/tests/finite_volume/two_phase/mixture_model/segregated/lid-driven-two-phase-physics.i)
(modules/navier_stokes/test/tests/finite_volume/two_phase/mixture_model/segregated/rayleigh-bernard-two-phase-physics.i)
(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/2d/2d-boussinesq-transient.i)
(modules/navier_stokes/test/tests/finite_volume/two_phase/mixture_model/segregated/rayleigh-bernard-two-phase-physics_heated.i)
(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/steady-transient-compare/pimple.i)

References

Christopher Greenshields and Henry Weller. Notes on Computational Fluid Dynamics: General Principles. CFD Direct Ltd, Reading, UK, 2022.

@book{greenshieldsweller2022,
    author = "Greenshields, Christopher and Weller, Henry",
    title = "Notes on Computational Fluid Dynamics: General Principles",
    year = "2022",
    publisher = "CFD Direct Ltd",
    address = "Reading, UK"
}

Raad I Issa. Solution of the implicitly discretised fluid flow equations by operator-splitting. Journal of computational physics, 62(1):40–65, 1986.

@article{issa1986solution,
    author = "Issa, Raad I",
    title = "Solution of the implicitly discretised fluid flow equations by operator-splitting",
    journal = "Journal of computational physics",
    volume = "62",
    number = "1",
    pages = "40--65",
    year = "1986",
    publisher = "Elsevier"
}

(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/2d/2d-boussinesq-transient.i)

mu = 2.6
rho = 1.0
advected_interp_method = 'average'
cp = 300
k = 10
alpha_b = 1e-4

[Mesh]
  [mesh]
    type = CartesianMeshGenerator
    dim = 2
    dx = '1.'
    dy = '0.2'
    ix = '10'
    iy = '5'
  []
[]

[Problem]
  linear_sys_names = 'u_system v_system pressure_system energy_system'
  previous_nl_solution_required = true
[]

[UserObjects]
  [rc]
    type = RhieChowMassFlux
    u = vel_x
    v = vel_y
    pressure = pressure
    rho = ${rho}
    p_diffusion_kernel = p_diffusion
  []
[]

[Variables]
  [vel_x]
    type = MooseLinearVariableFVReal
    initial_condition = 0.5
    solver_sys = u_system
  []
  [vel_y]
    type = MooseLinearVariableFVReal
    solver_sys = v_system
    initial_condition = 0.0
  []
  [pressure]
    type = MooseLinearVariableFVReal
    solver_sys = pressure_system
    initial_condition = 0.2
  []
  [T]
    type = MooseLinearVariableFVReal
    solver_sys = energy_system
    initial_condition = 300
  []
[]

[LinearFVKernels]
  [u_time]
    type = LinearFVTimeDerivative
    variable = vel_x
    factor = ${rho}
  []
  [v_time]
    type = LinearFVTimeDerivative
    variable = vel_y
    factor = ${rho}
  []
  [u_advection_stress]
    type = LinearWCNSFVMomentumFlux
    variable = vel_x
    advected_interp_method = ${advected_interp_method}
    mu = ${mu}
    u = vel_x
    v = vel_y
    momentum_component = 'x'
    rhie_chow_user_object = 'rc'
    use_nonorthogonal_correction = false
  []
  [v_advection_stress]
    type = LinearWCNSFVMomentumFlux
    variable = vel_y
    advected_interp_method = ${advected_interp_method}
    mu = ${mu}
    u = vel_x
    v = vel_y
    momentum_component = 'y'
    rhie_chow_user_object = 'rc'
    use_nonorthogonal_correction = false
  []
  [u_pressure]
    type = LinearFVMomentumPressure
    variable = vel_x
    pressure = pressure
    momentum_component = 'x'
  []
  [v_pressure]
    type = LinearFVMomentumPressure
    variable = vel_y
    pressure = pressure
    momentum_component = 'y'
  []
  [u_boussinesq]
    type = LinearFVMomentumBoussinesq
    variable = vel_x
    rho = ${rho}
    gravity = '0 -9.81 0'
    alpha_name = ${alpha_b}
    ref_temperature = 300.0
    T_fluid = T
    momentum_component = 'x'
  []
  [v_boussinesq]
    type = LinearFVMomentumBoussinesq
    variable = vel_y
    rho = ${rho}
    gravity = '0 -9.81 0'
    alpha_name = ${alpha_b}
    ref_temperature = 300.0
    T_fluid = T
    momentum_component = 'y'
  []

  [p_diffusion]
    type = LinearFVAnisotropicDiffusion
    variable = pressure
    diffusion_tensor = Ainv
    use_nonorthogonal_correction = false
  []
  [HbyA_divergence]
    type = LinearFVDivergence
    variable = pressure
    face_flux = HbyA
    force_boundary_execution = true
  []

  [h_time]
    type = LinearFVTimeDerivative
    variable = T
    factor = ${fparse rho*cp}
  []
  [h_advection]
    type = LinearFVEnergyAdvection
    variable = T
    advected_quantity = temperature
    cp = ${cp}
    advected_interp_method = ${advected_interp_method}
    rhie_chow_user_object = 'rc'
  []
  [conduction]
    type = LinearFVDiffusion
    variable = T
    diffusion_coeff = ${k}
    use_nonorthogonal_correction = false
  []
[]

[FunctorMaterials]
  [constant_functors]
    type = GenericFunctorMaterial
    prop_names = 'cp alpha_b'
    prop_values = '${cp} ${alpha_b}'
  []
[]

[LinearFVBCs]
  [inlet-u]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'left'
    variable = vel_x
    functor = '1.1'
  []
  [inlet-v]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'left'
    variable = vel_y
    functor = '0.0'
  []
  [walls-u]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'top bottom'
    variable = vel_x
    functor = 0.0
  []
  [walls-v]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'top bottom'
    variable = vel_y
    functor = 0.0
  []
  [outlet_p]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'right'
    variable = pressure
    functor = 1.4
  []
  [outlet_u]
    type = LinearFVAdvectionDiffusionOutflowBC
    variable = vel_x
    use_two_term_expansion = false
    boundary = right
  []
  [outlet_v]
    type = LinearFVAdvectionDiffusionOutflowBC
    variable = vel_y
    use_two_term_expansion = false
    boundary = right
  []
  [inlet_top_T]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = T
    functor = 300.0
    boundary = 'left top'
  []
  [bottom_T]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = T
    functor = wall-temperature
    boundary = bottom
  []
  [outlet_T]
    type = LinearFVAdvectionDiffusionOutflowBC
    variable = T
    use_two_term_expansion = false
    boundary = right
  []
[]

[Functions]
  [wall-temperature]
    type = ParsedFunction
    expression = '350 + 50 * sin(6.28*t)'
  []
[]

[Executioner]
  type = PIMPLE
  momentum_l_abs_tol = 1e-12
  pressure_l_abs_tol = 1e-12
  energy_l_abs_tol = 1e-12
  momentum_l_tol = 1e-12
  pressure_l_tol = 1e-12
  energy_l_tol = 1e-12
  rhie_chow_user_object = 'rc'
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  energy_system = 'energy_system'
  momentum_equation_relaxation = 0.8
  pressure_variable_relaxation = 0.3
  energy_equation_relaxation = 0.9
  num_iterations = 100
  pressure_absolute_tolerance = 1e-11
  momentum_absolute_tolerance = 1e-11
  energy_absolute_tolerance = 1e-11
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  energy_petsc_options_iname = '-pc_type -pc_hypre_type'
  energy_petsc_options_value = 'hypre boomeramg'
  print_fields = false
  continue_on_max_its = true
  dt = 0.01
  num_steps = 6
  num_piso_iterations = 0
[]


[Outputs]
  exodus = true
[]

(modules/navier_stokes/examples/flow-over-circle/flow_over_circle_linearfv.i)

[Problem]
  linear_sys_names = 'u_system v_system pressure_system'
  previous_nl_solution_required = true
[]

[Functions]
  [inlet_function]
    type = ParsedFunction
    expression = '4*U*(y-ymin)*(ymax-y)/(ymax-ymin)/(ymax-ymin)'
    symbol_names = 'U ymax ymin'
    symbol_values = '${inlet_velocity} ${y_max} ${y_min}'
  []
[]

[UserObjects]
  [rc]
    type = RhieChowMassFlux
    u = vel_x
    v = vel_y
    pressure = pressure
    rho = ${rho}
    p_diffusion_kernel = p_diffusion
  []
[]

[Variables]
  [vel_x]
    type = MooseLinearVariableFVReal
    solver_sys = u_system
  []
  [vel_y]
    type = MooseLinearVariableFVReal
    solver_sys = v_system
  []
  [pressure]
    type = MooseLinearVariableFVReal
    initial_condition = 0
    solver_sys = pressure_system
  []
[]

[LinearFVKernels]
  [u_time]
    type = LinearFVTimeDerivative
    variable = vel_x
    factor = ${rho}
  []
  [u_advection_stress]
    type = LinearWCNSFVMomentumFlux
    variable = vel_x
    advected_interp_method = ${advected_interp_method}
    mu = ${mu}
    u = vel_x
    v = vel_y
    momentum_component = 'x'
    rhie_chow_user_object = 'rc'
    use_nonorthogonal_correction = true
  []
  [u_pressure]
    type = LinearFVMomentumPressure
    variable = vel_x
    pressure = pressure
    momentum_component = 'x'
  []

  [v_time]
    type = LinearFVTimeDerivative
    variable = vel_y
    factor = ${rho}
  []
  [v_advection_stress]
    type = LinearWCNSFVMomentumFlux
    variable = vel_y
    advected_interp_method = ${advected_interp_method}
    mu = ${mu}
    u = vel_x
    v = vel_y
    momentum_component = 'y'
    rhie_chow_user_object = 'rc'
    use_nonorthogonal_correction = true
  []
  [v_pressure]
    type = LinearFVMomentumPressure
    variable = vel_y
    pressure = pressure
    momentum_component = 'y'
  []

  [p_diffusion]
    type = LinearFVAnisotropicDiffusion
    variable = pressure
    diffusion_tensor = Ainv
    use_nonorthogonal_correction = true
  []
  [HbyA_divergence]
    type = LinearFVDivergence
    variable = pressure
    face_flux = HbyA
    force_boundary_execution = true
  []
[]

[LinearFVBCs]
  [inlet_x]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = vel_x
    boundary = 'left_boundary'
    functor = 'inlet_function'
  []
  [inlet_y]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = vel_y
    boundary = 'left_boundary'
    functor = 0
  []
  [circle_x]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = vel_x
    boundary = 'circle'
    functor = 0
  []
  [circle_y]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = vel_y
    boundary = 'circle'
    functor = 0
  []
  [walls_x]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = vel_x
    boundary = 'top_boundary bottom_boundary'
    functor = 0
  []
  [walls_y]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = vel_y
    boundary = 'top_boundary bottom_boundary'
    functor = 0
  []
  [outlet_p]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'right_boundary'
    variable = pressure
    functor = 0
  []
  [outlet_u]
    type = LinearFVAdvectionDiffusionOutflowBC
    variable = vel_x
    use_two_term_expansion = false
    boundary = 'right_boundary'
  []
  [outlet_v]
    type = LinearFVAdvectionDiffusionOutflowBC
    variable = vel_y
    use_two_term_expansion = false
    boundary = 'right_boundary'
  []
[]

[Postprocessors]
  [drag_force]
    type = IntegralDirectedSurfaceForce
    vel_x = vel_x
    vel_y = vel_y
    mu = ${mu}
    pressure = pressure
    principal_direction = '1 0 0'
    boundary = 'circle'
    outputs = none
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [drag_coeff]
    type = ParsedPostprocessor
    expression = '2*drag_force/rho/(avgvel*avgvel)/D'
    constant_names = 'rho avgvel D'
    constant_expressions = '${rho} ${fparse 2/3*inlet_velocity} ${fparse 2*circle_radius}'
    pp_names = 'drag_force'
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [lift_force]
    type = IntegralDirectedSurfaceForce
    vel_x = vel_x
    vel_y = vel_y
    mu = ${mu}
    pressure = pressure
    principal_direction = '0 1 0'
    boundary = 'circle'
    outputs = none
    execute_on = 'INITIAL TIMESTEP_END'
  []
  [lift_coeff]
    type = ParsedPostprocessor
    expression = '2*lift_force/rho/(avgvel*avgvel)/D'
    constant_names = 'rho avgvel D'
    constant_expressions = '${rho} ${fparse 2/3*inlet_velocity} ${fparse 2*circle_radius}'
    pp_names = 'lift_force'
    execute_on = 'INITIAL TIMESTEP_END'
  []
[]

[Executioner]
  type = PIMPLE
  momentum_l_abs_tol = 1e-12
  pressure_l_abs_tol = 1e-12
  momentum_l_tol = 1e-12
  pressure_l_tol = 1e-12
  rhie_chow_user_object = 'rc'
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  momentum_equation_relaxation = 0.90
  pressure_variable_relaxation = 0.4
  num_iterations = 100
  pressure_absolute_tolerance = 1e-10
  momentum_absolute_tolerance = 1e-10
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  print_fields = false
  continue_on_max_its = true
  dt = 0.01
  num_steps = 500
[]

[Outputs]
  exodus = true
  csv = true
[]

(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/1d-scalar/channel-transient-physics.i)

mu = 2.6
rho = 1.0
advected_interp_method = 'upwind'
k1 = 0.1
k2 = 0.2

[Mesh]
  [mesh]
    type = CartesianMeshGenerator
    dim = 1
    dx = '0.25 0.25'
    ix = '5 5'
    subdomain_id = '0 1'
  []
[]

[Problem]
  linear_sys_names = 'u_system pressure_system s1_system s2_system'
[]

[Physics]
  [NavierStokes]
    [FlowSegregated]
      [flow]
        velocity_variable = 'vel_x'
        pressure_variable = 'pressure'

        initial_velocity = '0.5 0 0'
        initial_pressure = '0.2'

        density = ${rho}
        dynamic_viscosity = ${mu}

        # use inlet for moving wall to match the reference input
        # we could also use a noslip BC with a velocity wall functor
        inlet_boundaries = 'left'
        momentum_inlet_types = 'fixed-velocity'
        momentum_inlet_functors = '1.1'

        outlet_boundaries = 'right'
        momentum_outlet_types = 'fixed-pressure'
        pressure_functors = '1.4'

        orthogonality_correction = false
        pressure_two_term_bc_expansion = false
        momentum_two_term_bc_expansion = false
        momentum_advection_interpolation = ${advected_interp_method}
      []
    []
    [ScalarTransportSegregated]
      [scalar]
        passive_scalar_names = 'scalar1 scalar2'
        system_names = 's1_system s2_system'
        initial_scalar_variables = '1.1 3'

        passive_scalar_diffusivity = '${k1} ${k2}'

        passive_scalar_inlet_types = 'fixed-value fixed-value'
        passive_scalar_inlet_function = '1; 2'

        passive_scalar_advection_interpolation = ${advected_interp_method}
        passive_scalar_two_term_bc_expansion = false
        use_nonorthogonal_correction = false
      []
    []
  []
[]

[Executioner]
  type = PIMPLE
  momentum_l_abs_tol = 1e-13
  pressure_l_abs_tol = 1e-13
  passive_scalar_l_abs_tol = 1e-13
  momentum_l_tol = 0
  pressure_l_tol = 0
  passive_scalar_l_tol = 0
  rhie_chow_user_object = 'ins_rhie_chow_interpolator'
  momentum_systems = 'u_system'
  pressure_system = 'pressure_system'
  passive_scalar_systems = 's1_system s2_system'
  momentum_equation_relaxation = 0.4
  passive_scalar_equation_relaxation = '0.9 0.9'
  pressure_variable_relaxation = 0.3
  # We need to converge the problem to show conservation
  num_iterations = 1000
  pressure_absolute_tolerance = 1e-10
  momentum_absolute_tolerance = 1e-10
  passive_scalar_absolute_tolerance = '1e-9 1e-9'
  momentum_petsc_options_iname = '-pc_type' # -pc_hypre_type'
  momentum_petsc_options_value = 'lu'
  pressure_petsc_options_iname = '-pc_type' # -pc_hypre_type'
  pressure_petsc_options_value = 'lu' #hypre boomeramg'
  passive_scalar_petsc_options_iname = '-pc_type' # -pc_hypre_type'
  passive_scalar_petsc_options_value = 'lu' #hypre boomeramg'
  print_fields = false
  continue_on_max_its = true

  # Time stepping parameters
  end_time = 5
  dt = 1
[]

[Outputs]
  exodus = false
  execute_on = timestep_end
  [csv]
    type = CSV
    hide = 'balance_s1 balance_s2'
  []
[]

[GlobalParams]
  rhie_chow_user_object = 'ins_rhie_chow_interpolator'
  subtract_mesh_velocity = false
  advected_interp_method = ${advected_interp_method}
[]

[Postprocessors]
  [s1_in]
    type = VolumetricFlowRate
    boundary = left
    vel_x = vel_x
    advected_quantity = 'scalar1'
  []
  [s2_in]
    type = VolumetricFlowRate
    boundary = left
    vel_x = vel_x
    advected_quantity = 'scalar2'
  []
  [s1_out]
    type = VolumetricFlowRate
    boundary = right
    vel_x = vel_x
    advected_quantity = 'scalar1'
  []
  [s2_out]
    type = VolumetricFlowRate
    boundary = right
    vel_x = vel_x
    advected_quantity = 'scalar2'
  []
  [balance_s1]
    type = ParsedPostprocessor
    expression = 's1_out + s1_in'
    pp_names = 's1_in s1_out'
  []
  [balance_s2]
    type = ParsedPostprocessor
    expression = 's2_out + s2_in'
    pp_names = 's2_in s2_out'
  []
[]

(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/2d/2d-boussinesq-transient-physics.i)

mu = 2.6
rho = 1.0
advected_interp_method = 'average'
cp = 300
k = 10
alpha_b = 1e-4

[Mesh]
  [mesh]
    type = CartesianMeshGenerator
    dim = 2
    dx = '1.'
    dy = '0.2'
    ix = '10'
    iy = '5'
  []
[]

[Problem]
  linear_sys_names = 'u_system v_system pressure_system energy_system'
  previous_nl_solution_required = true
[]

[Physics]
  [NavierStokes]
    [FlowSegregated/flow]
      velocity_variable = 'vel_x vel_y'
      pressure_variable = 'pressure'
      fluid_temperature_variable = 'T'

      initial_velocity = '0.5 0 0'
      initial_pressure = '0.2'

      density = ${rho}
      dynamic_viscosity = ${mu}

      # To match non-physics-setup test
      solve_for_dynamic_pressure = true

      boussinesq_approximation = true
      ref_temperature = 300
      gravity = '0 -9.81 0'
      thermal_expansion = 'alpha_b'

      # use inlet for moving wall to match the reference input
      # we could also use a noslip BC with a velocity wall functor
      inlet_boundaries = 'left'
      momentum_inlet_types = 'fixed-velocity'
      momentum_inlet_functors = '1.1 0'

      outlet_boundaries = 'right'
      momentum_outlet_types = 'fixed-pressure'
      pressure_functors = '1.4'

      wall_boundaries = 'bottom top'
      momentum_wall_types = 'noslip noslip'

      orthogonality_correction = false
      momentum_two_term_bc_expansion = false
      pressure_two_term_bc_expansion = false
      momentum_advection_interpolation = ${advected_interp_method}
    []
    [FluidHeatTransferSegregated/energy]
      fluid_temperature_variable = 'T'
      thermal_conductivity = ${k}
      specific_heat = ${cp}

      initial_temperature = 300

      # Left is an inlet
      energy_inlet_types = 'fixed-temperature'
      energy_inlet_functors = '300'

      # Top and bottom are fixed temperature 'inlets' in the reference kernel-based input
      energy_wall_types = 'fixed-temperature fixed-temperature'
      energy_wall_functors = 'wall-temperature 300'

      energy_advection_interpolation = ${advected_interp_method}
      energy_two_term_bc_expansion = false
      use_nonorthogonal_correction = false
    []
  []
[]

[FunctorMaterials]
  [constant_functors]
    type = GenericFunctorMaterial
    prop_names = 'cp alpha_b rho_cp'
    prop_values = '${cp} ${alpha_b} ${fparse rho * cp}'
  []
[]

[Functions]
  [wall-temperature]
    type = ParsedFunction
    expression = '350 + 50 * sin(6.28*t)'
  []
[]

[Executioner]
  type = PIMPLE
  momentum_l_abs_tol = 1e-12
  pressure_l_abs_tol = 1e-12
  energy_l_abs_tol = 1e-12
  momentum_l_tol = 1e-12
  pressure_l_tol = 1e-12
  energy_l_tol = 1e-12
  rhie_chow_user_object = 'ins_rhie_chow_interpolator'
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  energy_system = 'energy_system'
  momentum_equation_relaxation = 0.8
  pressure_variable_relaxation = 0.3
  energy_equation_relaxation = 0.9
  num_iterations = 100
  pressure_absolute_tolerance = 1e-11
  momentum_absolute_tolerance = 1e-11
  energy_absolute_tolerance = 1e-11
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  energy_petsc_options_iname = '-pc_type -pc_hypre_type'
  energy_petsc_options_value = 'hypre boomeramg'
  print_fields = false
  continue_on_max_its = true
  dt = 0.01
  num_steps = 6
  num_piso_iterations = 0
[]


[Outputs]
  exodus = true
[]

(modules/navier_stokes/test/tests/finite_volume/two_phase/mixture_model/segregated/lid-driven-two-phase-physics.i)

mu = 1.0
rho = 1.0e3
mu_d = 0.3
rho_d = 5e2
dp = 0.01
U_lid = 0.1
advected_interp_method = 'upwind'

k = 1
k_d = 1
cp = 1
cp_d = 1

[Mesh]
  inactive = 'make_skew'
  [gen]
    type = GeneratedMeshGenerator
    dim = 2
    xmin = 0
    xmax = .1
    ymin = 0
    ymax = .1
    nx = 10
    ny = 10
  []
  [make_skew]
    type = MoveNodeGenerator
    input = 'gen'
    node_id = 0
    shift_position = '0.007 0.0021 0'
  []
[]

[Problem]
  linear_sys_names = 'u_system v_system pressure_system phi_system'
[]

[Physics]
  [NavierStokes]
    [FlowSegregated]
      [flow]
        compressibility = 'incompressible'

        density = 'rho_mixture'
        dynamic_viscosity = 'mu_mixture'

        # Initial conditions
        initial_velocity = '1e-12 1e-12 0'
        initial_pressure = 0.2

        wall_boundaries = 'top left right bottom'
        momentum_wall_types = 'noslip noslip noslip noslip'
        momentum_wall_functors = '${U_lid} 0; 0 0; 0 0; 0 0'

        orthogonality_correction = false
        pressure_two_term_bc_expansion = true
        momentum_advection_interpolation = ${advected_interp_method}
      []
    []
    [TwoPhaseMixtureSegregated]
      [mixture]
        system_names = 'phi_system'
        phase_1_fraction_name = 'phase_1'
        phase_2_fraction_name = 'phase_2'

        add_phase_transport_equation = true
        phase_advection_interpolation = '${advected_interp_method}'
        phase_fraction_diffusivity = 1e-3

        # We could consider adding fixed-value-yet-not-an-inlet
        # boundary conditions to the TwoPhaseMixture physics

        # Base phase material properties
        phase_1_density_name = ${rho}
        phase_1_viscosity_name = ${mu}
        phase_1_specific_heat_name = ${cp}
        phase_1_thermal_conductivity_name = ${k}

        # Other phase material properties
        phase_2_density_name = ${rho_d}
        phase_2_viscosity_name = ${mu_d}
        phase_2_specific_heat_name = ${cp_d}
        phase_2_thermal_conductivity_name = ${k_d}
        output_all_properties = true

        # Friction model, not actually used!
        use_dispersed_phase_drag_model = true
        particle_diameter = ${dp}
        add_advection_slip_term = false
      []
    []
  []
[]

[LinearFVBCs]
  [botttom-phase-2]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'bottom'
    variable = phase_2
    functor = '0'
  []
  [top-phase-2]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'top'
    variable = phase_2
    functor = '1'
  []
[]

[Executioner]
  type = PIMPLE
  rhie_chow_user_object = 'ins_rhie_chow_interpolator'
  dt = 1
  end_time = 10

  # Systems
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  active_scalar_systems = 'phi_system'
  momentum_equation_relaxation = 0.8
  active_scalar_equation_relaxation = '0.7'
  pressure_variable_relaxation = 0.3

  # We need to converge the problem to show conservation
  num_iterations = 200
  pressure_absolute_tolerance = 1e-10
  momentum_absolute_tolerance = 1e-10
  active_scalar_absolute_tolerance = '1e-10'
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  active_scalar_petsc_options_iname = '-pc_type -pc_factor_shift_type' # -pc_hypre_type'
  active_scalar_petsc_options_value = 'lu NONZERO'
  momentum_l_abs_tol = 1e-13
  pressure_l_abs_tol = 1e-13
  active_scalar_l_abs_tol = 1e-13
  momentum_l_tol = 0
  pressure_l_tol = 0
  active_scalar_l_tol = 0
  # print_fields = true
  continue_on_max_its = true

  pin_pressure = true
  pressure_pin_value = 0.0
  pressure_pin_point = '0.05 0.05 0.0'
[]

[Outputs]
  exodus = true
  [out]
    type = CSV
    execute_on = 'FINAL'
  []
[]

[AuxVariables]
  [drag_coefficient]
    type = MooseVariableFVReal
  []
[]

[AuxKernels]
  [populate_cd]
    type = FunctorAux
    variable = drag_coefficient
    functor = 'Darcy_coefficient'
    execute_on = 'TIMESTEP_END'
  []
[]

[Postprocessors]
  [average_void]
    type = ElementAverageValue
    variable = 'phase_2'
  []
  [max_y_velocity]
    type = ElementExtremeValue
    variable = 'vel_y'
    value_type = max
  []
  [min_y_velocity]
    type = ElementExtremeValue
    variable = 'vel_y'
    value_type = min
  []
  [max_x_velocity]
    type = ElementExtremeValue
    variable = 'vel_x'
    value_type = max
  []
  [min_x_velocity]
    type = ElementExtremeValue
    variable = 'vel_x'
    value_type = min
  []
  [max_x_slip_velocity]
    type = ElementExtremeFunctorValue
    functor = 'vel_slip_x'
    value_type = max
  []
  [max_y_slip_velocity]
    type = ElementExtremeFunctorValue
    functor = 'vel_slip_y'
    value_type = max
  []
  [max_drag_coefficient]
    type = ElementExtremeFunctorValue
    functor = 'drag_coefficient'
    value_type = max
  []
[]

(modules/navier_stokes/test/tests/finite_volume/two_phase/mixture_model/segregated/rayleigh-bernard-two-phase-physics.i)

mu = 1.0
rho = 1e3
mu_d = 0.3
rho_d = 1.0
dp = 0.01
U_lid = 0.0
g = -9.81
advected_interp_method = 'upwind'

# Currently required
k = 1
k_d = 1
cp = 1
cp_d = 1

[Mesh]
  [gen]
    type = GeneratedMeshGenerator
    dim = 2
    xmin = 0
    xmax = .1
    ymin = 0
    ymax = .1
    nx = 11
    ny = 11
  []
[]

[Problem]
  linear_sys_names = 'u_system v_system pressure_system phi_system'
[]

[Physics]
  [NavierStokes]
    [FlowSegregated]
      [flow]
        compressibility = 'incompressible'

        density = 'rho_mixture'
        dynamic_viscosity = 'mu_mixture'
        gravity = '0 ${g} 0'

        # Initial conditions
        initial_velocity = '1e-12 1e-12 0'
        initial_pressure = 0.2

        wall_boundaries = 'top left right bottom'
        momentum_wall_types = 'noslip noslip noslip noslip'
        momentum_wall_functors = '${U_lid} 0; 0 0; 0 0; 0 0'

        orthogonality_correction = false
        pressure_two_term_bc_expansion = true
        momentum_advection_interpolation = ${advected_interp_method}
      []
    []
    [TwoPhaseMixtureSegregated]
      [mixture]
        system_names = 'phi_system'
        phase_1_fraction_name = 'phase_1'
        phase_2_fraction_name = 'phase_2'

        add_phase_transport_equation = true
        phase_advection_interpolation = '${advected_interp_method}'
        phase_fraction_diffusivity = 1e-3

        # We could consider adding fixed-value-yet-not-an-inlet
        # boundary conditions to the TwoPhaseMixture physics

        # Base phase material properties
        phase_1_density_name = ${rho}
        phase_1_viscosity_name = ${mu}
        phase_1_specific_heat_name = ${cp}
        phase_1_thermal_conductivity_name = ${k}

        # Other phase material properties
        phase_2_density_name = ${rho_d}
        phase_2_viscosity_name = ${mu_d}
        phase_2_specific_heat_name = ${cp_d}
        phase_2_thermal_conductivity_name = ${k_d}
        output_all_properties = true

        # Friction model, not actually used!
        use_dispersed_phase_drag_model = true
        particle_diameter = ${dp}
        add_advection_slip_term = false
        # To match Rayleigh Bernard nonlinear test setup
        add_gravity_term_in_slip_velocity = false
      []
    []
  []
[]

[LinearFVBCs]
  [botttom-phase-2]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'bottom'
    variable = phase_2
    functor = '1'
  []
  [top-phase-2]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'top'
    variable = phase_2
    functor = '0'
  []
[]

[Executioner]
  type = PIMPLE
  rhie_chow_user_object = 'ins_rhie_chow_interpolator'

  end_time = 1e8
  [TimeStepper]
    type = IterationAdaptiveDT
    optimal_iterations = 10
    iteration_window = 2
    growth_factor = 2
    cutback_factor = 0.5
    dt = 1e-3
  []

  # Systems
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  active_scalar_systems = 'phi_system'
  momentum_equation_relaxation = 0.8
  active_scalar_equation_relaxation = '0.7'
  pressure_variable_relaxation = 0.3

  # We need to converge the problem to show conservation
  num_iterations = 200
  pressure_absolute_tolerance = 1e-10
  momentum_absolute_tolerance = 1e-10
  active_scalar_absolute_tolerance = '1e-10'
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  active_scalar_petsc_options_iname = '-pc_type -pc_factor_shift_type' # -pc_hypre_type'
  active_scalar_petsc_options_value = 'lu NONZERO'
  momentum_l_abs_tol = 1e-13
  pressure_l_abs_tol = 1e-13
  active_scalar_l_abs_tol = 1e-13
  momentum_l_tol = 0
  pressure_l_tol = 0
  active_scalar_l_tol = 0
  # print_fields = true
  continue_on_max_its = true

  pin_pressure = true
  pressure_pin_value = 0.0
  pressure_pin_point = '0.0 0.0 0.0'
[]

[Outputs]
  exodus = false
  [out]
    type = CSV
    execute_on = 'FINAL'
  []
[]

[AuxVariables]
  [U]
    order = CONSTANT
    family = MONOMIAL
    fv = true
  []
[]

[Postprocessors]
  [average_void]
    type = ElementAverageValue
    variable = 'phase_2'
  []
  [max_y_velocity]
    type = ElementExtremeValue
    variable = 'vel_y'
    value_type = max
  []
  [min_y_velocity]
    type = ElementExtremeValue
    variable = 'vel_y'
    value_type = min
  []
  [max_x_velocity]
    type = ElementExtremeValue
    variable = 'vel_x'
    value_type = max
  []
  [min_x_velocity]
    type = ElementExtremeValue
    variable = 'vel_x'
    value_type = min
  []
  [max_x_slip_velocity]
    type = ElementExtremeFunctorValue
    functor = 'vel_slip_x'
    value_type = max
  []
  [max_y_slip_velocity]
    type = ElementExtremeFunctorValue
    functor = 'vel_slip_y'
    value_type = max
  []
  [max_drag_coefficient_x]
    type = ElementExtremeFunctorValue
    functor = 'Darcy_coefficient_vec_out_x'
    value_type = max
  []
  [max_drag_coefficient_y]
    type = ElementExtremeFunctorValue
    functor = 'Darcy_coefficient_vec_out_y'
    value_type = max
  []
[]

(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/2d/2d-boussinesq-transient.i)

mu = 2.6
rho = 1.0
advected_interp_method = 'average'
cp = 300
k = 10
alpha_b = 1e-4

[Mesh]
  [mesh]
    type = CartesianMeshGenerator
    dim = 2
    dx = '1.'
    dy = '0.2'
    ix = '10'
    iy = '5'
  []
[]

[Problem]
  linear_sys_names = 'u_system v_system pressure_system energy_system'
  previous_nl_solution_required = true
[]

[UserObjects]
  [rc]
    type = RhieChowMassFlux
    u = vel_x
    v = vel_y
    pressure = pressure
    rho = ${rho}
    p_diffusion_kernel = p_diffusion
  []
[]

[Variables]
  [vel_x]
    type = MooseLinearVariableFVReal
    initial_condition = 0.5
    solver_sys = u_system
  []
  [vel_y]
    type = MooseLinearVariableFVReal
    solver_sys = v_system
    initial_condition = 0.0
  []
  [pressure]
    type = MooseLinearVariableFVReal
    solver_sys = pressure_system
    initial_condition = 0.2
  []
  [T]
    type = MooseLinearVariableFVReal
    solver_sys = energy_system
    initial_condition = 300
  []
[]

[LinearFVKernels]
  [u_time]
    type = LinearFVTimeDerivative
    variable = vel_x
    factor = ${rho}
  []
  [v_time]
    type = LinearFVTimeDerivative
    variable = vel_y
    factor = ${rho}
  []
  [u_advection_stress]
    type = LinearWCNSFVMomentumFlux
    variable = vel_x
    advected_interp_method = ${advected_interp_method}
    mu = ${mu}
    u = vel_x
    v = vel_y
    momentum_component = 'x'
    rhie_chow_user_object = 'rc'
    use_nonorthogonal_correction = false
  []
  [v_advection_stress]
    type = LinearWCNSFVMomentumFlux
    variable = vel_y
    advected_interp_method = ${advected_interp_method}
    mu = ${mu}
    u = vel_x
    v = vel_y
    momentum_component = 'y'
    rhie_chow_user_object = 'rc'
    use_nonorthogonal_correction = false
  []
  [u_pressure]
    type = LinearFVMomentumPressure
    variable = vel_x
    pressure = pressure
    momentum_component = 'x'
  []
  [v_pressure]
    type = LinearFVMomentumPressure
    variable = vel_y
    pressure = pressure
    momentum_component = 'y'
  []
  [u_boussinesq]
    type = LinearFVMomentumBoussinesq
    variable = vel_x
    rho = ${rho}
    gravity = '0 -9.81 0'
    alpha_name = ${alpha_b}
    ref_temperature = 300.0
    T_fluid = T
    momentum_component = 'x'
  []
  [v_boussinesq]
    type = LinearFVMomentumBoussinesq
    variable = vel_y
    rho = ${rho}
    gravity = '0 -9.81 0'
    alpha_name = ${alpha_b}
    ref_temperature = 300.0
    T_fluid = T
    momentum_component = 'y'
  []

  [p_diffusion]
    type = LinearFVAnisotropicDiffusion
    variable = pressure
    diffusion_tensor = Ainv
    use_nonorthogonal_correction = false
  []
  [HbyA_divergence]
    type = LinearFVDivergence
    variable = pressure
    face_flux = HbyA
    force_boundary_execution = true
  []

  [h_time]
    type = LinearFVTimeDerivative
    variable = T
    factor = ${fparse rho*cp}
  []
  [h_advection]
    type = LinearFVEnergyAdvection
    variable = T
    advected_quantity = temperature
    cp = ${cp}
    advected_interp_method = ${advected_interp_method}
    rhie_chow_user_object = 'rc'
  []
  [conduction]
    type = LinearFVDiffusion
    variable = T
    diffusion_coeff = ${k}
    use_nonorthogonal_correction = false
  []
[]

[FunctorMaterials]
  [constant_functors]
    type = GenericFunctorMaterial
    prop_names = 'cp alpha_b'
    prop_values = '${cp} ${alpha_b}'
  []
[]

[LinearFVBCs]
  [inlet-u]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'left'
    variable = vel_x
    functor = '1.1'
  []
  [inlet-v]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'left'
    variable = vel_y
    functor = '0.0'
  []
  [walls-u]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'top bottom'
    variable = vel_x
    functor = 0.0
  []
  [walls-v]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'top bottom'
    variable = vel_y
    functor = 0.0
  []
  [outlet_p]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    boundary = 'right'
    variable = pressure
    functor = 1.4
  []
  [outlet_u]
    type = LinearFVAdvectionDiffusionOutflowBC
    variable = vel_x
    use_two_term_expansion = false
    boundary = right
  []
  [outlet_v]
    type = LinearFVAdvectionDiffusionOutflowBC
    variable = vel_y
    use_two_term_expansion = false
    boundary = right
  []
  [inlet_top_T]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = T
    functor = 300.0
    boundary = 'left top'
  []
  [bottom_T]
    type = LinearFVAdvectionDiffusionFunctorDirichletBC
    variable = T
    functor = wall-temperature
    boundary = bottom
  []
  [outlet_T]
    type = LinearFVAdvectionDiffusionOutflowBC
    variable = T
    use_two_term_expansion = false
    boundary = right
  []
[]

[Functions]
  [wall-temperature]
    type = ParsedFunction
    expression = '350 + 50 * sin(6.28*t)'
  []
[]

[Executioner]
  type = PIMPLE
  momentum_l_abs_tol = 1e-12
  pressure_l_abs_tol = 1e-12
  energy_l_abs_tol = 1e-12
  momentum_l_tol = 1e-12
  pressure_l_tol = 1e-12
  energy_l_tol = 1e-12
  rhie_chow_user_object = 'rc'
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  energy_system = 'energy_system'
  momentum_equation_relaxation = 0.8
  pressure_variable_relaxation = 0.3
  energy_equation_relaxation = 0.9
  num_iterations = 100
  pressure_absolute_tolerance = 1e-11
  momentum_absolute_tolerance = 1e-11
  energy_absolute_tolerance = 1e-11
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  energy_petsc_options_iname = '-pc_type -pc_hypre_type'
  energy_petsc_options_value = 'hypre boomeramg'
  print_fields = false
  continue_on_max_its = true
  dt = 0.01
  num_steps = 6
  num_piso_iterations = 0
[]


[Outputs]
  exodus = true
[]

(modules/navier_stokes/test/tests/finite_volume/two_phase/mixture_model/segregated/rayleigh-bernard-two-phase-physics_heated.i)

mu = 1.0
rho = 1e3
mu_d = 0.3
rho_d = 1.0
dp = 0.01
U_lid = 0.0
g = -9.81
advected_interp_method = 'upwind'

T_fluid_top = 1

# Currently required
k = 1
k_d = 1
cp = 1
cp_d = 1

[Mesh]
  [gen]
    type = GeneratedMeshGenerator
    dim = 2
    xmin = 0
    xmax = .1
    ymin = 0
    ymax = .1
    nx = 10
    ny = 11
  []
[]

[Problem]
  linear_sys_names = 'u_system v_system pressure_system energy_system phi_system'
[]

# We are using a Materials block to order the functor creation.
# See #30827
[Materials]
  [T_from_p_h]
    type = ParsedFunctorMaterial
    property_name = 'T_from_p_h_functor'
    expression = 'h / cp_mixture'
    functor_names = 'h cp_mixture'
  []
  [h_from_p_T]
    type = ParsedFunctorMaterial
    property_name = 'h_from_p_T_functor'
    expression = 'cp_mixture * T_fluid'
    functor_names = 'T_fluid cp_mixture'
  []
  [density_1]
    type = ParsedFunctorMaterial
    property_name = 'rho'
    expression = '${rho} * (1. - 0.9 * T_fluid)'
    functor_names = 'T_fluid'
  []
  [density_2]
    type = ParsedFunctorMaterial
    property_name = 'rho_d'
    expression = '${rho_d} * (1. - 0.9 * T_fluid)'
    functor_names = 'T_fluid'
  []
[]

[Physics]
  [NavierStokes]
    [FlowSegregated]
      [flow]
        compressibility = 'weakly-compressible'

        density = 'rho_mixture'
        dynamic_viscosity = 'mu_mixture'
        gravity = '0 ${g} 0'

        # Initial conditions
        initial_velocity = '1e-12 1e-12 0'
        initial_pressure = 0.2

        wall_boundaries = 'top left right bottom'
        momentum_wall_types = 'noslip noslip noslip noslip'
        momentum_wall_functors = '${U_lid} 0; 0 0; 0 0; 0 0'

        orthogonality_correction = false
        pressure_two_term_bc_expansion = true
        momentum_advection_interpolation = ${advected_interp_method}
      []
    []
    [FluidHeatTransferSegregated]
      [heat]
        system_names = 'energy_system'
        # allows non-constant cp
        solve_for_enthalpy = true
        initial_temperature = ${T_fluid_top}

        thermal_conductivity = 'k_mixture'
        specific_heat = 'cp_mixture'

        energy_wall_boundaries = 'top          bottom'
        energy_wall_types = 'fixed-temperature fixed-temperature'
        energy_wall_functors = '0              1'

        use_nonorthogonal_correction = false
        energy_two_term_bc_expansion = true
        energy_advection_interpolation = ${advected_interp_method}
      []
    []
    [TwoPhaseMixtureSegregated]
      [mixture]
        system_names = 'phi_system'
        phase_1_fraction_name = 'phase_1'
        phase_2_fraction_name = 'phase_2'

        # not fully mixed initialization
        initial_phase_fraction = 'unstable'

        add_phase_transport_equation = true
        phase_advection_interpolation = '${advected_interp_method}'
        phase_fraction_diffusivity = 1e-3

        fluid_heat_transfer_physics = heat

        # Base phase material properties
        phase_1_density_name = 'rho'
        phase_1_viscosity_name = ${mu}
        phase_1_specific_heat_name = ${cp}
        phase_1_thermal_conductivity_name = ${k}

        # Other phase material properties
        phase_2_density_name = 'rho_d'
        phase_2_viscosity_name = ${mu_d}
        phase_2_specific_heat_name = ${cp_d}
        phase_2_thermal_conductivity_name = ${k_d}
        output_all_properties = true

        # Friction model, not actually used!
        use_dispersed_phase_drag_model = true
        particle_diameter = ${dp}
        add_advection_slip_term = false
        # To match Rayleigh Bernard nonlinear test setup
        add_gravity_term_in_slip_velocity = false
      []
    []
  []
[]

[Functions]
  [unstable]
    type = ParsedFunction
    expression = 'if(y > 0.05, 1, 0)'
  []
[]

[Executioner]
  type = PIMPLE
  rhie_chow_user_object = 'ins_rhie_chow_interpolator'

  end_time = 1e8
  [TimeStepper]
    type = IterationAdaptiveDT
    optimal_iterations = 10
    iteration_window = 2
    growth_factor = 2
    cutback_factor = 0.5
    dt = 1e-3
  []

  # Systems
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  energy_system = 'energy_system'
  active_scalar_systems = 'phi_system'
  momentum_equation_relaxation = 0.8
  active_scalar_equation_relaxation = '0.7'
  energy_equation_relaxation = '0.5'
  pressure_variable_relaxation = 0.3

  # We need to converge the problem to show conservation
  num_iterations = 200
  pressure_absolute_tolerance = 1e-10
  momentum_absolute_tolerance = 1e-10
  energy_absolute_tolerance = 1e-10
  active_scalar_absolute_tolerance = '1e-10'
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  energy_petsc_options_iname = '-pc_type -pc_hypre_type'
  energy_petsc_options_value = 'hypre boomeramg'
  active_scalar_petsc_options_iname = '-pc_type -pc_factor_shift_type' # -pc_hypre_type'
  active_scalar_petsc_options_value = 'lu NONZERO'
  momentum_l_abs_tol = 1e-13
  pressure_l_abs_tol = 1e-13
  energy_l_abs_tol = 1e-13
  active_scalar_l_abs_tol = 1e-13
  momentum_l_tol = 0
  pressure_l_tol = 0
  energy_l_tol = 0
  active_scalar_l_tol = 0
  # print_fields = true
  continue_on_max_its = true

  pin_pressure = true
  pressure_pin_value = 0.0
  pressure_pin_point = '0.0 0.0 0.0'
[]

[Outputs]
  exodus = false
  [out]
    type = CSV
    execute_on = 'FINAL'
  []
[]

[AuxVariables]
  [U]
    order = CONSTANT
    family = MONOMIAL
    fv = true
  []
[]

[Postprocessors]
  [average_void]
    type = ElementAverageValue
    variable = 'phase_2'
  []
  [max_y_velocity]
    type = ElementExtremeValue
    variable = 'vel_y'
    value_type = max
  []
  [min_y_velocity]
    type = ElementExtremeValue
    variable = 'vel_y'
    value_type = min
  []
  [max_x_velocity]
    type = ElementExtremeValue
    variable = 'vel_x'
    value_type = max
  []
  [min_x_velocity]
    type = ElementExtremeValue
    variable = 'vel_x'
    value_type = min
  []
  [max_x_slip_velocity]
    type = ElementExtremeFunctorValue
    functor = 'vel_slip_x'
    value_type = max
  []
  [max_y_slip_velocity]
    type = ElementExtremeFunctorValue
    functor = 'vel_slip_y'
    value_type = max
  []
  [max_drag_coefficient_x]
    type = ElementExtremeFunctorValue
    functor = 'Darcy_coefficient_vec_out_x'
    value_type = max
  []
  [max_drag_coefficient_y]
    type = ElementExtremeFunctorValue
    functor = 'Darcy_coefficient_vec_out_y'
    value_type = max
  []
[]

(modules/navier_stokes/test/tests/finite_volume/ins/channel-flow/linear-segregated/steady-transient-compare/pimple.i)

[Times]
  [time_steps]
    type = InputTimes
    times = '1 1E2 1E4 1E5 1E6 1E7 2E7 4E7 6E7 8E7 1E8'
  []
[]

[Executioner]
  type = PIMPLE
  momentum_l_abs_tol = 1e-11
  pressure_l_abs_tol = 1e-11
  energy_l_abs_tol = 1e-11
  momentum_l_tol = 0
  pressure_l_tol = 0
  energy_l_tol = 0
  rhie_chow_user_object = 'rc'
  momentum_systems = 'u_system v_system'
  pressure_system = 'pressure_system'
  energy_system = 'energy_system'
  momentum_equation_relaxation = 0.9
  energy_equation_relaxation = 1.0
  pressure_variable_relaxation = 0.3
  num_iterations = 200
  pressure_absolute_tolerance = 1e-10
  momentum_absolute_tolerance = 1e-10
  energy_absolute_tolerance = 1e-10
  momentum_petsc_options_iname = '-pc_type -pc_hypre_type'
  momentum_petsc_options_value = 'hypre boomeramg'
  pressure_petsc_options_iname = '-pc_type -pc_hypre_type'
  pressure_petsc_options_value = 'hypre boomeramg'
  energy_petsc_options_iname = '-pc_type -pc_hypre_type'
  energy_petsc_options_value = 'hypre boomeramg'
  print_fields = false
  end_time = 1e8

  [TimeStepper]
    type = TimeSequenceFromTimes
    times = time_steps
  []
[]

Overview
Example Input Syntax
Input Parameters
Input Files
References