PressureReleaseFluxIntegral

Computes the integral of the flux over the specified boundary and over time.

Overview

This object computes the amount of pressure of a specie released into an enclosure from a neighboring structure. The units corresponding to the return of PressureReleaseFluxIntegral::computeQpResidual() should be pressure. Let's verify this. _diffusion_coef has units of length^{2/time; _grad_u has units of #/length}4; _normals is unitless; _area has units of length^{2; _volume has units of length}3; _concentration_to_pressure_conversion_factor has units of pressure/(#/length^3); _dt has units of time. Applying units to the code


Real
PressureReleaseFluxIntegral::computeQpIntegral()
{
  return -_diffusion_coef[_qp] * _grad_u[_qp] * _normals[_qp] * _area / _volume *
         _concentration_to_pressure_conversion_factor * _dt;
}

gives us

length^{2/time * #/length}4 * length^{2 / length}3 * pressure/(#/length^3) * time -> pressure which is exactly what we want.

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
diffusivityThe name of the diffusivity material property that will be used in the flux computation.
C++ Type:MaterialPropertyName
Unit:(no unit assumed)
Controllable:No
Description:The name of the diffusivity material property that will be used in the flux computation.
surface_areaThe surface area of the structure
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The surface area of the structure
variableThe name of the variable which this postprocessor integrates
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:The name of the variable which this postprocessor integrates
volumeThe volume of the enclosure
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The volume of the enclosure

Required Parameters

concentration_to_pressure_conversion_factor1The constant for converting from units of concentration to units of pressure
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:The constant for converting from units of concentration to units of pressure

Optional Parameters

allow_duplicate_execution_on_initialFalseIn the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).
Default:False
C++ Type:bool
Controllable:No
Description:In the case where this UserObject is depended upon by an initial condition, allow it to be executed twice during the initial setup (once before the IC and again after mesh adaptivity (if applicable).
execute_onTIMESTEP_ENDThe list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.
Default:TIMESTEP_END
C++ Type:ExecFlagEnum
Options:NONE, INITIAL, LINEAR, LINEAR_CONVERGENCE, NONLINEAR, NONLINEAR_CONVERGENCE, POSTCHECK, TIMESTEP_END, TIMESTEP_BEGIN, MULTIAPP_FIXED_POINT_END, MULTIAPP_FIXED_POINT_BEGIN, MULTIAPP_FIXED_POINT_CONVERGENCE, FINAL, CUSTOM, TRANSFER
Controllable:No
Description:The list of flag(s) indicating when this object should be executed. For a description of each flag, see https://mooseframework.inl.gov/source/interfaces/SetupInterface.html.
execution_order_group0Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.
Default:0
C++ Type:int
Controllable:No
Description:Execution order groups are executed in increasing order (e.g., the lowest number is executed first). Note that negative group numbers may be used to execute groups before the default (0) group. Please refer to the user object documentation for ordering of user object execution within a group.
force_postauxFalseForces the UserObject to be executed in POSTAUX
Default:False
C++ Type:bool
Controllable:No
Description:Forces the UserObject to be executed in POSTAUX
force_preauxFalseForces the UserObject to be executed in PREAUX
Default:False
C++ Type:bool
Controllable:No
Description:Forces the UserObject to be executed in PREAUX
force_preicFalseForces the UserObject to be executed in PREIC during initial setup
Default:False
C++ Type:bool
Controllable:No
Description:Forces the UserObject to be executed in PREIC during initial setup

Execution Scheduling 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.
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
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

prop_getter_suffixAn optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
C++ Type:MaterialPropertyName
Unit:(no unit assumed)
Controllable:No
Description:An optional suffix parameter that can be appended to any attempt to retrieve/get material properties. The suffix will be prepended with a '_' character.
use_interpolated_stateFalseFor the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.
Default:False
C++ Type:bool
Controllable:No
Description:For the old and older state use projected material properties interpolated at the quadrature points. To set up projection use the ProjectedStatefulMaterialStorageAction.

Material Property Retrieval Parameters

Input Files

(test/tests/ver-1a/ver-1a.i)

(test/tests/ver-1a/ver-1a.i)

# Verification Problem #1a from TMAP4/TMAP7 V&V document
# Tritium diffusion through SiC layer with depleting source at 2100 C.
# No Soret effect, solubility, or trapping included.

# Physical Constants
# Note that we do NOT use the same number of digits as in TMAP4/TMAP7.
# This is to be consistent with PhysicalConstant.h
kb = '${units 1.380649e-23 J/K}' # Boltzmann constant
R = '${units 8.31446261815324 J/mol/K}' # Gas constant

# Data used in TMAP4/TMAP7 case
temperature = '${units 2373 K}'
initial_pressure = '${units 1e6 Pa}'
volume_enclosure = '${units 5.20e-11 m^3 -> mum^3}'
surface_area = '${units 2.16e-6 m^2 -> mum^2}'
diffusivity_SiC = '${units ${fparse 1.58e-4*exp(-308000.0/(R*temperature))} m^2/s -> mum^2/s}'
solubility_constant = '${units ${fparse 7.244e22 / temperature} at/m^3/Pa -> at/mum^3/Pa}'
slab_thickness = '${units 3.30e-5 m -> mum}'

# Useful equations/conversions
concentration_to_pressure_conversion_factor = '${units ${fparse kb*temperature} Pa*m^3 -> Pa*mum^3}'

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 150
  xmax = '${slab_thickness}'
[]

[Variables]
  # concentration in the SiC layer in atoms/microns^3
  [u]
  []
  # pressure of the enclosure in Pa
  [v]
    family = SCALAR
    order = FIRST
    initial_condition = '${fparse initial_pressure}'
  []
[]

[Kernels]
  [diff]
    type = MatDiffusion
    variable = u
    diffusivity = '${diffusivity_SiC}'
  []
  [time]
    type = TimeDerivative
    variable = u
  []
[]

[ScalarKernels]
  [time]
    type = ODETimeDerivative
    variable = v
  []
  [flux_sink]
    type = EnclosureSinkScalarKernel
    variable = v
    flux = scaled_flux_surface_left
    surface_area = '${surface_area}'
    volume = '${volume_enclosure}'
    concentration_to_pressure_conversion_factor = '${concentration_to_pressure_conversion_factor}'
  []
[]

[BCs]
  # The concentration on the outer boundary of the SiC layer is kept at 0
  [right]
    type = DirichletBC
    value = 0
    variable = u
    boundary = 'right'
  []
  # The surface of the slab in contact with the source is assumed to be in equilibrium with the source enclosure
  [left]
    type = EquilibriumBC
    variable = u
    enclosure_var = v
    boundary = 'left'
    Ko = '${solubility_constant}'
    temperature = ${temperature}
  []
[]

[Postprocessors]
  # flux of tritium through the outer SiC surface - compare to TMAP7
  [flux_surface_right]
    type = SideDiffusiveFluxIntegral
    variable = u
    diffusivity = '${diffusivity_SiC}'
    boundary = 'right'
    execute_on = 'initial nonlinear linear timestep_end'
    outputs = 'console csv exodus'
  []
  # flux of tritium through the surface of SiC layer in contact with enclosure
  [flux_surface_left]
    type = SideDiffusiveFluxIntegral
    variable = u
    diffusivity = '${diffusivity_SiC}'
    boundary = 'left'
    execute_on = 'initial nonlinear linear timestep_end'
    outputs = ''
  []
  # scale the flux to get inward direction
  [scaled_flux_surface_left]
    type = ScalePostprocessor
    scaling_factor = -1
    value = flux_surface_left
    execute_on = 'initial nonlinear linear timestep_end'
    outputs = 'console csv exodus'
  []
  # integral of the tritium flux through outer surface of SiC layer
  [integral_release_flux_right]
    type = PressureReleaseFluxIntegral
    variable = u
    boundary = 'right'
    diffusivity = '${diffusivity_SiC}'
    surface_area = '${surface_area}'
    volume = '${volume_enclosure}'
    concentration_to_pressure_conversion_factor = '${concentration_to_pressure_conversion_factor}'
    outputs = 'console'
  []
  # cumulative sum of integral_release_flux_right over time (i.e. cumulative amount released)
  [cumulative_release_right]
    type = CumulativeValuePostprocessor
    postprocessor = 'integral_release_flux_right'
    outputs = 'console'
  []
  # released fraction based on outer layer flux - compare to TMAP4
  [released_fraction_right]
    type = ScalePostprocessor
    value = 'cumulative_release_right'
    scaling_factor = '${fparse 1./(initial_pressure)}'
    outputs = 'console csv exodus'
  []
  # Make a postprocessor take the value of the scalar value v
  [v_value]
    type = ScalarVariable
    variable = v
  []
  # released fraction based on inner layer flux on v - compare to TMAP7
  [released_fraction_left]
    type = LinearCombinationPostprocessor
    pp_names = 'v_value'
    pp_coefs = '${fparse -1./(initial_pressure)}'
    b = 1
  []
[]

[Executioner]
  type = Transient
  dt = .1
  end_time = 140
  solve_type = PJFNK
  automatic_scaling = true
  dtmin = .1
  l_max_its = 30
  nl_max_its = 5
  petsc_options = '-snes_converged_reason -ksp_monitor_true_residual'
  petsc_options_iname = '-pc_type -mat_mffd_err'
  petsc_options_value = 'lu       1e-5'
  line_search = 'bt'
  scheme = 'bdf2'
  timestep_tolerance = 1e-8
[]

[Outputs]
  exodus = true
  print_linear_residuals = false
  perf_graph = true
  [dof]
    type = DOFMap
    execute_on = 'initial'
  []
  [csv]
    type = CSV
    execute_on = 'initial timestep_end'
  []
[]

Overview
Input Parameters
Input Files