LBMFixedFirstOrderBC

LBMFixedFirstOrderBC object

LBMFixedFirstOrderBC implements Zou-He velocity boundary conditions at the inlet and outlet for D2Q9, D3Q19 and D3Q27 stencils.

Overview

Enforces first-order accurate macroscopic velocity at selected domain faces via Zou-He formulas. Choose faces with "boundary" and provide macroscopic fields as required by the implementation.

Example Input File Syntax

[TensorComputes<<<{"href": "../../syntax/TensorComputes/index.html"}>>>]
  [Boundary<<<{"href": "../../syntax/TensorComputes/Boundary/index.html"}>>>]
    [top]
      type = LBMFixedFirstOrderBC<<<{"description": "LBMFixedFirstOrderBC object", "href": "LBMFixedFirstOrderBC.html"}>>>
      buffer<<<{"description": "The buffer this compute is writing to"}>>> = f
      f<<<{"description": "Input buffer distribution function"}>>> = f
      value<<<{"description": "Fixed input velocity"}>>> = 0.0001
      boundary<<<{"description": "Edges/Faces where boundary condition is applied."}>>> = top
    []
  []
[]

Input Parameters

boundaryEdges/Faces where boundary condition is applied.
C++ Type:MooseEnum
Options:top, bottom, left, right, front, back, wall, regional
Controllable:No
Description:Edges/Faces where boundary condition is applied.
bufferThe buffer this compute is writing to
C++ Type:std::string
Controllable:No
Description:The buffer this compute is writing to
fInput buffer distribution function
C++ Type:std::string
Controllable:No
Description:Input buffer distribution function
valueFixed input velocity
C++ Type:std::string
Controllable:No
Description:Fixed input velocity

Required Parameters

perturbFalseWhether to perturb first order moment at the boundary
Default:False
C++ Type:bool
Controllable:No
Description:Whether to perturb first order moment at the boundary

Optional 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:No
Description:Set the enabled status of the MooseObject.

Advanced Parameters

(test/tests/lbm/vertical_velocity_bcs.i)

[Domain]
  dim = 2
  nx = 10
  ny = 10
  mesh_mode = DUMMY
  parallel_mode = REAL_SPACE
  periodic_directions = 'X Y'
[]

[Stencil]
  [d2q9]
    type = LBMD2Q9
  []
[]

[TensorBuffers]
  [f]
    type = LBMTensorBuffer
    buffer_type = df
  []
  [f_bounce_back]
    type = LBMTensorBuffer
    buffer_type = df
  []
  [velocity]
    type=LBMTensorBuffer
    buffer_type = mv
  []
  [density]
    type=LBMTensorBuffer
    buffer_type = ms
  []
[]

[TensorComputes]
  [Initialize]
    [initial_density]
      type = LBMConstantTensor
      buffer = density
      constants = 1.0
    []
    [initial_velocity]
      type = LBMConstantTensor
      buffer = velocity
      constants = '0.0001 0.0005'
    []
    [initial_f]
      type = LBMEquilibrium
      buffer = f
      bulk = density
      velocity = velocity
    []
    [initial_f_bb]
      type = LBMEquilibrium
      buffer = f_bounce_back
      bulk = density
      velocity = velocity
    []
  []
  [Solve]
    [density]
      type = LBMComputeDensity
      buffer = density
      f = f
    []
    [velocity]
      type = LBMComputeVelocity
      buffer = velocity
      f = f
      rho = density
      add_body_force = true
      body_force_x = 0.0001
    []
  []
  [Boundary]
    [left]
      type = LBMBounceBack
      buffer = f
      f_old = f_bounce_back
      boundary = left
    []
    [right]
      type = LBMBounceBack
      buffer = f
      f_old = f_bounce_back
      boundary = right
    []
    [top]
      type = LBMFixedFirstOrderBC
      buffer = f
      f = f
      value = 0.0001
      boundary = top
    []
    [bottom]
      type = LBMFixedFirstOrderBC
      buffer = f
      f = f
      value = 0.00011
      boundary = bottom
    []
  []
[]

[TensorSolver]
  type = LBMStream
  buffer = f
  f_old = f_bounce_back
[]

[Problem]
  type = LatticeBoltzmannProblem
  substeps = 2
[]

[Postprocessors]
  [velocity_min]
    type = TensorExtremeValuePostprocessor
    buffer = velocity
    value_type = MIN
  []
  [velocity_max]
    type = TensorExtremeValuePostprocessor
    buffer = velocity
    value_type = MAX
  []
  [density_min]
    type = TensorExtremeValuePostprocessor
    buffer = density
    value_type = MIN
  []
  [densty_max]
    type = TensorExtremeValuePostprocessor
    buffer = density
    value_type = MAX
  []
[]

[Executioner]
  type = Transient
  num_steps = 5
[]

[Outputs]
  file_base = vertical_velocity_bcs
  csv = true
[]

Overview
Example Input File Syntax
Input Parameters