LBMStackTensors

Stack given scalar tensor buffers and output vectorial tensor.

Stacks multiple scalar tensors to create one vectorial tensor buffer.

Overview

Stacks multiple scalar or vector buffers along the stencil index to form a distribution-like tensor with Q components per cell. Useful for constructing custom distribution arrays from component fields.

Example Input File Syntax

[TensorComputes<<<{"href": "../../syntax/TensorComputes/index.html"}>>>]
  [Initialize<<<{"href": "../../syntax/TensorComputes/Initialize/index.html"}>>>]
    [u_stack]
      type = LBMStackTensors<<<{"description": "Stack given scalar tensor buffers and output vectorial tensor.", "href": "LBMStackTensors.html"}>>>
      buffer<<<{"description": "The buffer this compute is writing to"}>>> = u
      inputs<<<{"description": "Names of input tensor buffers to stack."}>>> = 'ux uy'
    []
  []
[]

Input Parameters

bufferThe buffer this compute is writing to
C++ Type:std::string
Controllable:No
Description:The buffer this compute is writing to
inputsNames of input tensor buffers to stack.
C++ Type:std::vector<std::string>
Controllable:No
Description:Names of input tensor buffers to stack.

Required 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

Input Files

(test/tests/lbm/stacking.i)
(examples/lbm/Phase-field/droplet_impact.i)

(test/tests/lbm/stacking.i)

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

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

[TensorBuffers]
  [ux]
    type=LBMTensorBuffer
    buffer_type = ms
  []
  [uy]
    type=LBMTensorBuffer
    buffer_type = ms
  []
  [u]
    type=LBMTensorBuffer
    buffer_type = mv
  []
[]

[TensorComputes/Initialize]
  [velocity_x]
    type = ParsedCompute
    buffer = ux
    expression = '0.1*sin(x/(2*pi*4))*cos(y/(2*pi*4))'
    extra_symbols=true
  []
  [velocity_y]
    type = ParsedCompute
    buffer = uy
    expression = '-0.1*cos(x/(2*pi*4))*sin(y/(2*pi*4))'
    extra_symbols=true
  []
  [u_stack]
    type=LBMStackTensors
    buffer=u
    inputs='ux uy'
  []
[]

[Problem]
  type = LatticeBoltzmannProblem
  substeps = 1
[]

[Postprocessors]
  [velocity_x_min]
    type = TensorExtremeValuePostprocessor
    buffer = ux
    value_type = MIN
  []
  [velocity_x_max]
    type = TensorExtremeValuePostprocessor
    buffer = ux
    value_type = MAX
  []
  [velocity_y_min]
    type = TensorExtremeValuePostprocessor
    buffer = uy
    value_type = MIN
  []
  [velocity_y_max]
    type = TensorExtremeValuePostprocessor
    buffer = uy
    value_type = MAX
  []
  [u_stack_min]
    type = TensorExtremeValuePostprocessor
    buffer = u
    value_type = MIN
  []
  [u_stack_max]
    type = TensorExtremeValuePostprocessor
    buffer = u
    value_type = MAX
  []
[]

[Executioner]
  type = Transient
  num_steps = 2
[]

[Outputs]
  file_base = stacking
  csv = true
[]

(test/tests/lbm/stacking.i)

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

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

[TensorBuffers]
  [ux]
    type=LBMTensorBuffer
    buffer_type = ms
  []
  [uy]
    type=LBMTensorBuffer
    buffer_type = ms
  []
  [u]
    type=LBMTensorBuffer
    buffer_type = mv
  []
[]

[TensorComputes/Initialize]
  [velocity_x]
    type = ParsedCompute
    buffer = ux
    expression = '0.1*sin(x/(2*pi*4))*cos(y/(2*pi*4))'
    extra_symbols=true
  []
  [velocity_y]
    type = ParsedCompute
    buffer = uy
    expression = '-0.1*cos(x/(2*pi*4))*sin(y/(2*pi*4))'
    extra_symbols=true
  []
  [u_stack]
    type=LBMStackTensors
    buffer=u
    inputs='ux uy'
  []
[]

[Problem]
  type = LatticeBoltzmannProblem
  substeps = 1
[]

[Postprocessors]
  [velocity_x_min]
    type = TensorExtremeValuePostprocessor
    buffer = ux
    value_type = MIN
  []
  [velocity_x_max]
    type = TensorExtremeValuePostprocessor
    buffer = ux
    value_type = MAX
  []
  [velocity_y_min]
    type = TensorExtremeValuePostprocessor
    buffer = uy
    value_type = MIN
  []
  [velocity_y_max]
    type = TensorExtremeValuePostprocessor
    buffer = uy
    value_type = MAX
  []
  [u_stack_min]
    type = TensorExtremeValuePostprocessor
    buffer = u
    value_type = MIN
  []
  [u_stack_max]
    type = TensorExtremeValuePostprocessor
    buffer = u
    value_type = MAX
  []
[]

[Executioner]
  type = Transient
  num_steps = 2
[]

[Outputs]
  file_base = stacking
  csv = true
[]

(examples/lbm/Phase-field/droplet_impact.i)

#
# Droplet Impact on a Thin Liquid Film
# PHYSICAL REVIEW E 97, 033309 (2018) - Section III.D
#

# Domain
Nx = 1500
Ny = 500

# Fluid properties (Re=500, We=8000, 1000:1)
rho_l = 1000.0
rho_g = 1.0
# mu_l = 20.0
# mu_g = 0.2
nu_l = 0.02
nu_g = 0.2
sigma = 0.0625

# Phase field parameters
tau_h = 0.8
D = 5

[Domain]
  dim = 2
  nx = '${Nx}'
  ny = '${Ny}'
  xmax = '${Nx}'
  ymax = '${Ny}'
  device_names = 'cuda'
  parallel_mode = REAL_SPACE
  periodic_directions = 'X Y'
[]

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

[TensorBuffers]
  [phi]
    type = LBMTensorBuffer
    buffer_type = ms
    file = phi.h5
  []
  [ux]
    type = LBMTensorBuffer
    buffer_type = ms
    file = ux.h5
  []
  [uy]
    type = LBMTensorBuffer
    buffer_type = ms
    file = uy.h5
  []
  [velocity]
    type = LBMTensorBuffer
    buffer_type = mv
  []

  [grad_phi]
    type = LBMTensorBuffer
    buffer_type = mv
  []
  [laplacian_phi]
    type = LBMTensorBuffer
    buffer_type = ms
  []
  [mu]
    type = LBMTensorBuffer
    buffer_type = ms
  []
  [forces]
    type = LBMTensorBuffer
    buffer_type = mv
  []
  [speed]
    type = LBMTensorBuffer
    buffer_type = ms
  []
  [pressure]
    type = LBMTensorBuffer
    buffer_type = ms
  []
  [rho]
    type = LBMTensorBuffer
    buffer_type = ms
  []
  [h]
    type = LBMTensorBuffer
    buffer_type = df
  []
  [h_post_collision]
    type = LBMTensorBuffer
    buffer_type = df
  []
  [h_eq]
    type = LBMTensorBuffer
    buffer_type = df
  []
  [relaxation_tensor]
    type = LBMTensorBuffer
    buffer_type = ms
  []
  [f]
    type = LBMTensorBuffer
    buffer_type = df
  []
  [f_post_collision]
    type = LBMTensorBuffer
    buffer_type = df
  []
  [f_eq]
    type = LBMTensorBuffer
    buffer_type = df
  []
[]

[TensorComputes/Initialize]
  [u_stack]
    type = LBMStackTensors
    buffer = velocity
    inputs = 'ux uy'
  []

  [grad_phi_init]
    type = LBMIsotropicGradient
    buffer = grad_phi
    scalar_field = phi
  []
  [rho_init]
    type = ParsedCompute
    buffer = rho
    expression = 'phi * (rho_l - rho_g) + rho_g'
    constant_names = 'rho_l rho_g'
    constant_expressions = '${rho_l} ${rho_g}'
    inputs = phi
  []
  [pressure_init]
    type = LBMConstantTensor
    buffer = pressure
    constants = 0.3
  []

  # Equilibrium
  [h_eq_init]
    type = LBMPhaseEquilibrium
    buffer = h_eq
    phi = phi
    velocity = velocity
  []
  [h_init]
    type = ParsedCompute
    buffer = h
    expression = 'h_eq'
    inputs = h_eq
  []
  [h_post_collision_init]
    type = ParsedCompute
    buffer = h_post_collision
    expression = 'h_eq'
    inputs = h_eq
  []
  [f_eq_init]
    type = LBMPressureCorrectedEquilibrium
    buffer = f_eq
    rho = rho
    velocity = velocity
    pressure = pressure
  []
  [f_init]
    type = ParsedCompute
    buffer = f
    expression = 'f_eq'
    inputs = f_eq
  []
  [f_post_collision_init]
    type = ParsedCompute
    buffer = f_post_collision
    expression = 'f_eq'
    inputs = f_eq
  []
[]

[TensorComputes/Solve]
  [compute_phi]
    type = LBMComputeDensity
    buffer = phi
    f = h
  []
  [grad_phi]
    type = LBMIsotropicGradient
    buffer = grad_phi
    scalar_field = phi
  []
  [laplacian_phi]
    type = LBMIsotropicLaplacian
    buffer = laplacian_phi
    scalar_field = phi
  []
  [potential]
    type = LBMComputeChemicalPotential
    buffer = mu
    phi = phi
    laplacian_phi = laplacian_phi
    thickness = D
    sigma = sigma
  []
  [compute_forces]
    type = LBMComputeSurfaceForces
    buffer = forces
    chemical_potential = mu
    grad_phi = grad_phi
  []
  [density]
    type = ParsedCompute
    buffer = rho
    expression = 'phi * (rho_l - rho_g) + rho_g'
    constant_names = 'rho_l rho_g'
    constant_expressions = '${rho_l} ${rho_g}'
    inputs = phi
  []
  [velocity]
    type = LBMComputeVelocity
    buffer = velocity
    f = f
    rho = rho
    enable_forces = true
    forces = forces
  []
  [h_eq]
    type = LBMPhaseEquilibrium
    buffer = h_eq
    phi = phi
    velocity = velocity
  []
  [phase_collision]
    type = LBMBGKCollision
    buffer = h_post_collision
    f = h
    feq = h_eq
    tau0 = tau_h
  []
  [apply_forces_phase]
    type = LBMAllenCahnSource
    buffer = h_post_collision
    phi = phi
    velocity = velocity
    grad_phi = grad_phi
    tau = tau_h
    thickness = D
  []
  [relaxation_tensor]
    type = ParsedCompute
    buffer = relaxation_tensor
    expression = '(phi * (nu_l - nu_g) + nu_g) / cs2 + 0.5'
    constant_names = 'nu_l nu_g cs2'
    constant_expressions = '${nu_l} ${nu_g} 0.333333333333'
    inputs = 'phi'
  []
  [pressure]
    type = LBMPhaseFieldPressure
    buffer = pressure
    f = f
    velocity = velocity
    grad_phi = grad_phi
    rho = rho
    rho_l = '${rho_l}'
    rho_g = '${rho_g}'
  []
  [f_eq]
    type = LBMPressureCorrectedEquilibrium
    buffer = f_eq
    rho = rho
    velocity = velocity
    pressure = pressure
  []
  [collision]
    type = LBMBGKCollision
    buffer = f_post_collision
    f = f
    feq = f_eq
    tau0 = 1.0
    is_dynamic_relaxation = true
    tau_tensor = relaxation_tensor
  []
  [apply_forces_hydro]
    type = LBMForceDistribution
    buffer = f_post_collision
    grad_phi = grad_phi
    velocity = velocity
    forces = forces
    tau_tensor = relaxation_tensor
    tau = 1.0
    rho_l = '${rho_l}'
    rho_g = '${rho_g}'
    is_dynamic_relaxation = true
  []
  [residual]
    type = LBMComputeResidual
    buffer = phi
    speed = phi
  []
[]

[TensorComputes/Boundary]
  # Bounce back on both top and bottom
  [top_fluid]
    type = LBMBounceBack
    buffer = f
    f_old = f_post_collision
    boundary = top
  []
  [bottom_fluid]
    type = LBMBounceBack
    buffer = f
    f_old = f_post_collision
    boundary = bottom
  []
  [top_phase]
    type = LBMBounceBack
    buffer = h
    f_old = h_post_collision
    boundary = top
  []
  [bottom_phase]
    type = LBMBounceBack
    buffer = h
    f_old = h_post_collision
    boundary = bottom
  []
[]

[TensorSolver]
  type = LBMStream
  buffer = 'h f'
  f_old = 'h_post_collision f_post_collision'
  root_compute = residual
[]

[Problem]
  type = LatticeBoltzmannProblem
  substeps = 200
  print_debug_output = true
  scalar_constant_names = 'tau_h D sigma'
  scalar_constant_values = '${tau_h} ${D} ${sigma}'
[]

[Executioner]
  type = Transient
  num_steps = 50
[]

[TensorOutputs]
  [xdmf]
    type = XDMFTensorOutput
    buffer = 'phi velocity rho'
    output_mode = 'Cell Cell Cell'
    enable_hdf5 = true
    transpose = false
  []
[]

Overview
Example Input File Syntax
Input Parameters
Input Files