WCNSFVInletVelocityBC

Defines a Dirichlet boundary condition for finite volume method.

There are two options for specifying a component of the inlet velocity:

specifying a velocity postprocessor
specifying a mass flow rate postprocessor and a density functor. The functor is usually a functor material property, defined by a GeneralFunctorFluidProps. The scaling factor can be used to account for projections if the inlet flow and the surface are not aligned.

This boundary condition works with postprocessors, which may be replaced by constant values in the input. The intended use case for this boundary condition is to be receiving its value from a coupled application, using a Receiver postprocessor.

note

Specifying the inlet velocity using a WCNSFVInletVelocityBC will not preserve mass or momentum flow at the boundary in most cases, in part because of the discretization error. Specifying incoming mass and momentum fluxes using a WCNSFVMassFluxBC and a WCNSFVMomentumFluxBC is currently the only conservative approach.

Example input syntax

In this example input, the boundary conditions to the mass conservation equation and the momentum equations are specified using two WCNSFVInletVelocityBC, one for each component of the velocity. The inlet velocity is specified using a mass flow rate postprocessor.

[FVBCs]
  # Inlet
  [inlet_u]
    type = WCNSFVInletVelocityBC
    variable = u
    boundary = 'left'
    mdot_pp = 'inlet_mdot'
    area_pp = 'surface_inlet'
    rho = 'rho'
  []
  [inlet_v]
    type = WCNSFVInletVelocityBC
    variable = v
    boundary = 'left'
    mdot_pp = 0
    area_pp = 'surface_inlet'
    rho = 'rho'
  []
  [inlet_T]
    type = WCNSFVInletTemperatureBC
    variable = T
    boundary = 'left'
    temperature_pp = 'inlet_T'
  []

  [outlet_p]
    type = INSFVOutletPressureBC
    variable = pressure
    boundary = 'right'
    function = ${outlet_pressure}
  []

  # Walls
  [no_slip_x]
    type = INSFVNoSlipWallBC
    variable = u
    boundary = 'top bottom'
    function = 0
  []
  [no_slip_y]
    type = INSFVNoSlipWallBC
    variable = v
    boundary = 'top bottom'
    function = 0
  []
[]

Input Parameters

boundaryThe list of boundary IDs from the mesh where this object applies
C++ Type:std::vector<BoundaryName>
Controllable:No
Description:The list of boundary IDs from the mesh where this object applies
variableThe name of the variable that this boundary condition applies to
C++ Type:NonlinearVariableName
Controllable:No
Description:The name of the variable that this boundary condition applies to

Required Parameters

area_ppInlet area as a postprocessor
C++ Type:PostprocessorName
Controllable:No
Description:Inlet area as a postprocessor
displacementsThe displacements
C++ Type:std::vector<VariableName>
Controllable:No
Description:The displacements
mdot_ppPostprocessor with the inlet mass flow rate
C++ Type:PostprocessorName
Controllable:No
Description:Postprocessor with the inlet mass flow rate
rhoDensity functor
C++ Type:MooseFunctorName
Controllable:No
Description:Density functor
scaling_factor1To scale the velocity
Default:1
C++ Type:double
Controllable:No
Description:To scale the velocity
velocity_ppPostprocessor with the inlet velocity
C++ Type:PostprocessorName
Controllable:No
Description:Postprocessor with the inlet velocity

Optional Parameters

absolute_value_vector_tagsThe tags for the vectors this residual object should fill with the absolute value of the residual contribution
C++ Type:std::vector<TagName>
Controllable:No
Description:The tags for the vectors this residual object should fill with the absolute value of the residual contribution
extra_matrix_tagsThe extra tags for the matrices this Kernel should fill
C++ Type:std::vector<TagName>
Controllable:No
Description:The extra tags for the matrices this Kernel should fill
extra_vector_tagsThe extra tags for the vectors this Kernel should fill
C++ Type:std::vector<TagName>
Controllable:No
Description:The extra tags for the vectors this Kernel should fill
matrix_tagssystemThe tag for the matrices this Kernel should fill
Default:system
C++ Type:MultiMooseEnum
Options:nontime, system
Controllable:No
Description:The tag for the matrices this Kernel should fill
vector_tagsnontimeThe tag for the vectors this Kernel should fill
Default:nontime
C++ Type:MultiMooseEnum
Options:nontime, time
Controllable:No
Description:The tag for the vectors this Kernel should fill

Tagging Parameters

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.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:Yes
Description:Set the enabled status of the MooseObject.
implicitTrueDetermines whether this object is calculated using an implicit or explicit form
Default:True
C++ Type:bool
Controllable:No
Description:Determines whether this object is calculated using an implicit or explicit form
use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Advanced Parameters

(moose/modules/navier_stokes/test/tests/finite_volume/wcns/boundary_conditions/dirichlet_bcs_mdot.i)

rho = 'rho'
l = 10
inlet_area = 1
velocity_interp_method = 'rc'
advected_interp_method = 'average'

# Artificial fluid properties
# For a real case, use a GeneralFluidFunctorProperties and a viscosity rampdown
# or initialize very well!
k = 1
cp = 1000
mu = 1e2

# Operating conditions
inlet_temp = 300
outlet_pressure = 1e5
inlet_velocity = 0.001

[Mesh]
  [gen]
    type = GeneratedMeshGenerator
    dim = 2
    xmin = 0
    xmax = ${l}
    ymin = 0
    ymax = 1
    nx = 10
    ny = 5
  []
[]

[GlobalParams]
  rhie_chow_user_object = 'rc'
[]

[UserObjects]
  [rc]
    type = INSFVRhieChowInterpolator
    u = u
    v = v
    pressure = pressure
  []
[]

[Variables]
  [u]
    type = INSFVVelocityVariable
    initial_condition = ${inlet_velocity}
  []
  [v]
    type = INSFVVelocityVariable
    initial_condition = 1e-15
  []
  [pressure]
    type = INSFVPressureVariable
    initial_condition = ${outlet_pressure}
  []
  [T]
    type = INSFVEnergyVariable
    initial_condition = ${inlet_temp}
  []
[]

[AuxVariables]
  [power_density]
    type = MooseVariableFVReal
    initial_condition = 1e4
  []
[]

[FVKernels]
  [mass_time]
    type = WCNSFVMassTimeDerivative
    variable = pressure
    drho_dt = drho_dt
  []
  [mass]
    type = INSFVMassAdvection
    variable = pressure
    advected_interp_method = ${advected_interp_method}
    velocity_interp_method = ${velocity_interp_method}
    rho = ${rho}
  []

  [u_time]
    type = WCNSFVMomentumTimeDerivative
    variable = u
    drho_dt = drho_dt
    rho = rho
    momentum_component = 'x'
  []
  [u_advection]
    type = INSFVMomentumAdvection
    variable = u
    velocity_interp_method = ${velocity_interp_method}
    advected_interp_method = ${advected_interp_method}
    rho = ${rho}
    momentum_component = 'x'
  []
  [u_viscosity]
    type = INSFVMomentumDiffusion
    variable = u
    mu = ${mu}
    momentum_component = 'x'
  []
  [u_pressure]
    type = INSFVMomentumPressure
    variable = u
    momentum_component = 'x'
    pressure = pressure
  []

  [v_time]
    type = WCNSFVMomentumTimeDerivative
    variable = v
    drho_dt = drho_dt
    rho = rho
    momentum_component = 'y'
  []
  [v_advection]
    type = INSFVMomentumAdvection
    variable = v
    velocity_interp_method = ${velocity_interp_method}
    advected_interp_method = ${advected_interp_method}
    rho = ${rho}
    momentum_component = 'y'
  []
  [v_viscosity]
    type = INSFVMomentumDiffusion
    variable = v
    mu = ${mu}
    momentum_component = 'y'
  []
  [v_pressure]
    type = INSFVMomentumPressure
    variable = v
    momentum_component = 'y'
    pressure = pressure
  []

  [temp_time]
    type = WCNSFVEnergyTimeDerivative
    variable = T
    cp = cp
    rho = rho
    drho_dt = drho_dt
  []
  [temp_conduction]
    type = FVDiffusion
    coeff = 'k'
    variable = T
  []
  [temp_advection]
    type = INSFVEnergyAdvection
    variable = T
    velocity_interp_method = ${velocity_interp_method}
    advected_interp_method = ${advected_interp_method}
  []
  [heat_source]
    type = FVCoupledForce
    variable = T
    v = power_density
  []
[]

[FVBCs]
  # Inlet
  [inlet_u]
    type = WCNSFVInletVelocityBC
    variable = u
    boundary = 'left'
    mdot_pp = 'inlet_mdot'
    area_pp = 'surface_inlet'
    rho = 'rho'
  []
  [inlet_v]
    type = WCNSFVInletVelocityBC
    variable = v
    boundary = 'left'
    mdot_pp = 0
    area_pp = 'surface_inlet'
    rho = 'rho'
  []
  [inlet_T]
    type = WCNSFVInletTemperatureBC
    variable = T
    boundary = 'left'
    temperature_pp = 'inlet_T'
  []

  [outlet_p]
    type = INSFVOutletPressureBC
    variable = pressure
    boundary = 'right'
    function = ${outlet_pressure}
  []

  # Walls
  [no_slip_x]
    type = INSFVNoSlipWallBC
    variable = u
    boundary = 'top bottom'
    function = 0
  []
  [no_slip_y]
    type = INSFVNoSlipWallBC
    variable = v
    boundary = 'top bottom'
    function = 0
  []
[]

# used for the boundary conditions in this example
[Postprocessors]
  [inlet_mdot]
    type = Receiver
    default = ${fparse 1980 * inlet_velocity * inlet_area}
  []
  [surface_inlet]
    type = AreaPostprocessor
    boundary = 'left'
    execute_on = 'INITIAL'
  []
  [inlet_T]
    type = Receiver
    default = ${inlet_temp}
  []
[]

[FluidProperties]
  [fp]
    type = FlibeFluidProperties
  []
[]

[Materials]
  [const_functor]
    type = ADGenericFunctorMaterial
    prop_names = 'cp k'
    prop_values = '${cp} ${k}'
  []
  [rho]
    type = RhoFromPTFunctorMaterial
    fp = fp
    temperature = T
    pressure = pressure
  []
  [ins_fv]
    type = INSFVEnthalpyMaterial
    temperature = 'T'
    rho = ${rho}
  []
[]

[Executioner]
  type = Transient
  solve_type = 'NEWTON'
  petsc_options_iname = '-pc_type -pc_factor_shift_type'
  petsc_options_value = 'lu       NONZERO'

  [TimeStepper]
    type = IterationAdaptiveDT
    dt = 1e-2
    optimal_iterations = 6
  []
  end_time = 1

  nl_abs_tol = 1e-9
  nl_max_its = 50
  line_search = 'none'

  automatic_scaling = true
[]

[Outputs]
  exodus = true
  execute_on = 'FINAL'
[]

Example input syntax
Input Parameters