ActuallyExplicitEuler

This time integrator is an implementation of forward/explicit Euler based on ExplicitTimeIntegrator, which avoids a nonlinear solve.

Input Parameters

solve_typeconsistentThe way to solve the system. A 'consistent' solve uses the full mass matrix and actually needs to use a linear solver to solve the problem. 'lumped' uses a lumped mass matrix with a simple inversion - incredibly fast but may be less accurate. 'lump_preconditioned' uses the lumped mass matrix as a preconditioner for the 'consistent' solve
Default:consistent
C++ Type:MooseEnum
Options:consistent lumped lump_preconditioned
Description:The way to solve the system. A 'consistent' solve uses the full mass matrix and actually needs to use a linear solver to solve the problem. 'lumped' uses a lumped mass matrix with a simple inversion - incredibly fast but may be less accurate. 'lump_preconditioned' uses the lumped mass matrix as a preconditioner for the 'consistent' solve

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector
Options:
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Options:
Description:Set the enabled status of the MooseObject.

Advanced Parameters

Input Files

test/tests/time_integrators/actually_explicit_euler/actually_explicit_euler_lumped.i
test/tests/time_integrators/actually_explicit_euler_verification/ee-1d-quadratic-neumann.i
test/tests/time_integrators/actually_explicit_euler_verification/ee-1d-quadratic.i
test/tests/time_integrators/actually_explicit_euler_verification/ee-ode.i
test/tests/time_integrators/actually_explicit_euler/actually_explicit_euler_lump_preconditioned.i
test/tests/time_integrators/actually_explicit_euler_verification/ee-2d-linear-adapt.i
test/tests/time_integrators/actually_explicit_euler/diverged.i
test/tests/time_integrators/actually_explicit_euler/actually_explicit_euler.i
test/tests/time_integrators/actually_explicit_euler_verification/ee-1d-linear.i
test/tests/time_integrators/actually_explicit_euler_verification/ee-2d-quadratic.i
test/tests/time_integrators/actually_explicit_euler_verification/ee-2d-linear.i

test/tests/time_integrators/actually_explicit_euler/actually_explicit_euler_lumped.i

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [./u]
  [../]
[]

[Kernels]
  [./diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    preset = false
    boundary = 'left'
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    preset = false
    boundary = 'right'
    value = 1
  [../]
[]

[Executioner]
  type = Transient
  num_steps = 10
  dt = 0.001


  [./TimeIntegrator]
    type = ActuallyExplicitEuler
    solve_type = lumped
  [../]
[]

[Outputs]
  exodus = true
[]

test/tests/time_integrators/actually_explicit_euler_verification/ee-1d-quadratic-neumann.i

[Mesh]
  type = GeneratedMesh
  dim = 1
  xmin = -1
  xmax = 1
  nx = 10
  elem_type = EDGE3
[]

[Functions]
  [./ic]
    type = ParsedFunction
    value = 0
  [../]

  [./forcing_fn]
    type = ParsedFunction
    value = x*x-2*t+t*x*x
  [../]

  [./exact_fn]
    type = ParsedFunction
    value = t*x*x
  [../]

  [./left_bc_fn]
    type = ParsedFunction
    value = -t*2*x
  [../]
  [./right_bc_fn]
    type = ParsedFunction
    value = t*2*x
  [../]
[]

[Variables]
  [./u]
    order = SECOND
    family = LAGRANGE

    [./InitialCondition]
      type = FunctionIC
      function = ic
    [../]
  [../]
[]

[Kernels]
  [./td]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./abs]
    type = Reaction
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./left]
    type = FunctionNeumannBC
    variable = u
    boundary = '0'
    function = left_bc_fn
  [../]

  [./right]
    type = FunctionNeumannBC
    variable = u
    boundary = '1'
    function = right_bc_fn
  [../]
[]

[Postprocessors]
  [./l2_err]
    type = ElementL2Error
    variable = u
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient

  l_tol = 1e-12
  start_time = 0.0
  num_steps = 10
  dt = 0.001

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
  [../]
[]

[Outputs]
  exodus = true
  [./console]
    type = Console
    max_rows = 10
  [../]
[]

test/tests/time_integrators/actually_explicit_euler_verification/ee-1d-quadratic.i

[Mesh]
  type = GeneratedMesh
  dim = 1
  xmin = -1
  xmax = 1
  nx = 20
  elem_type = EDGE3
[]

[Functions]
  [./ic]
    type = ParsedFunction
    value = 0
  [../]

  [./forcing_fn]
    type = ParsedFunction
    value = x*x-2*t
  [../]

  [./exact_fn]
    type = ParsedFunction
    value = t*x*x
  [../]
[]

[Variables]
  [./u]
    order = SECOND
    family = LAGRANGE

    [./InitialCondition]
      type = FunctionIC
      function = ic
    [../]
  [../]
[]

[Kernels]
  [./ie]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    preset = false
    boundary = '0 1'
    function = exact_fn
  [../]
[]

[Postprocessors]
  [./l2_err]
    type = ElementL2Error
    variable = u
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient

  l_tol = 1e-12
  start_time = 0.0
  num_steps = 20
  dt = 0.00005

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
  [../]
[]

[Outputs]
  exodus = true
  [./console]
    type = Console
    max_rows = 10
  [../]
[]

test/tests/time_integrators/actually_explicit_euler_verification/ee-ode.i

# Tests that ActuallyExplicitEuler works with scalar variables.
#
# The ODE and IC used are the following:
#   du/dt = 2,       u(0) = 0
# Thus the solution is u(t) = 2*t.

[Mesh]
  type = GeneratedMesh
  dim = 1
  nx = 1
[]

[Variables]
  [./u]
    family = SCALAR
    order = FIRST
    initial_condition = 0
  [../]
[]

[ScalarKernels]
  [./time]
    type = ODETimeDerivative
    variable = u
  [../]
  [./source]
    type = ParsedODEKernel
    variable = u
    function = -2
  [../]
[]

[Executioner]
  type = Transient

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
  [../]
  dt = 1
  num_steps = 5
[]

[Outputs]
  csv = true
[]

test/tests/time_integrators/actually_explicit_euler/actually_explicit_euler_lump_preconditioned.i

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [./u]
  [../]
[]

[Kernels]
  [./diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    preset = false
    boundary = 'left'
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    preset = false
    boundary = 'right'
    value = 1
  [../]
[]

[Executioner]
  type = Transient
  num_steps = 10
  dt = 0.0001
  l_tol = 1e-12

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
    solve_type = lump_preconditioned
  [../]
[]

[Outputs]
  exodus = true
[]

test/tests/time_integrators/actually_explicit_euler_verification/ee-2d-linear-adapt.i

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax = 1
  ymin = -1
  ymax = 1
  nx = 10
  ny = 10
  elem_type = QUAD4
[]

[Functions]
  [./ic]
    type = ParsedFunction
    value = 0
  [../]

  [./forcing_fn]
    type = ParsedFunction
    value = (x+y)
  [../]

  [./exact_fn]
    type = ParsedFunction
    value = t*(x+y)
  [../]
[]

[Variables]
  [./u]
    order = FIRST
    family = LAGRANGE

    [./InitialCondition]
      type = FunctionIC
      function = ic
    [../]
  [../]
[]

[Kernels]
  [./ie]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    preset = false
    boundary = '0 1 2 3'
    function = exact_fn
  [../]
[]

[Adaptivity]
  steps = 1
  marker = box
  max_h_level = 2
  [./Markers]
    [./box]
      bottom_left = '-0.4 -0.4 0'
      inside = refine
      top_right = '0.4 0.4 0'
      outside = do_nothing
      type = BoxMarker
    [../]
  [../]
[]

[Postprocessors]
  [./l2_err]
    type = ElementL2Error
    variable = u
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient

  start_time = 0.0
  num_steps = 4
  dt = 0.005
  l_tol = 1e-12

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
  [../]
[]

[Outputs]
  exodus = true
  [./console]
    type = Console
    max_rows = 10
  [../]
[]

test/tests/time_integrators/actually_explicit_euler/diverged.i

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [./u]
  [../]
[]

[Kernels]
  [./diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  [../]
  [./nan]
    type = NanKernel
    variable = u
    timestep_to_nan = 4
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    boundary = 'left'
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    boundary = 'right'
    value = 1
  [../]
[]

[Executioner]
  type = Transient
  num_steps = 10
  dt = 0.001
  l_tol = 1e-12
  dtmin = 1e-8

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
    solve_type = lump_preconditioned
  [../]
[]

[Outputs]
  exodus = false
[]

test/tests/time_integrators/actually_explicit_euler/actually_explicit_euler.i

[Mesh]
  type = GeneratedMesh
  dim = 2
  nx = 10
  ny = 10
[]

[Variables]
  [./u]
  [../]
[]

[Kernels]
  [./diff]
    type = CoefDiffusion
    variable = u
    coef = 0.1
  [../]
  [./time]
    type = TimeDerivative
    variable = u
  [../]
[]

[BCs]
  [./left]
    type = DirichletBC
    variable = u
    preset = false
    boundary = 'left'
    value = 0
  [../]
  [./right]
    type = DirichletBC
    variable = u
    preset = false
    boundary = 'right'
    value = 1
  [../]
[]

[Executioner]
  type = Transient
  num_steps = 10
  dt = 0.001
  l_tol = 1e-12

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
  [../]
[]

[Outputs]
  exodus = true
[]

test/tests/time_integrators/actually_explicit_euler_verification/ee-1d-linear.i

[Mesh]
  type = GeneratedMesh
  dim = 1
  xmin = -1
  xmax = 1
  nx = 200
  elem_type = EDGE2
[]

[Functions]
  [./ic]
    type = ParsedFunction
    value = 0
  [../]

  [./forcing_fn]
    type = ParsedFunction
    value = x
  [../]

  [./exact_fn]
    type = ParsedFunction
    value = t*x
  [../]
[]

[Variables]
  [./u]
    order = FIRST
    family = LAGRANGE

    [./InitialCondition]
      type = FunctionIC
      function = ic
    [../]
  [../]
[]

[Kernels]
  [./ie]
    type = TimeDerivative
    variable = u
    lumping = true
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    preset = false
    boundary = '0 1'
    function = exact_fn
  [../]
[]

[Postprocessors]
  [./l2_err]
    type = ElementL2Error
    variable = u
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient

  start_time = 0.0
  num_steps = 20
  dt = 0.00005

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
  [../]
[]

[Outputs]
  exodus = true
  [./console]
    type = Console
    max_rows = 10
  [../]
[]

test/tests/time_integrators/actually_explicit_euler_verification/ee-2d-quadratic.i

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax = 1
  ymin = -1
  ymax = 1
  nx = 10
  ny = 10
  elem_type = QUAD9
[]

[Functions]
  [./ic]
    type = ParsedFunction
    value = 0
  [../]

  [./forcing_fn]
    type = ParsedFunction
    value = ((x*x)+(y*y))-(4*t)
  [../]

  [./exact_fn]
    type = ParsedFunction
    value = t*((x*x)+(y*y))
  [../]
[]

[Variables]
  [./u]
    order = SECOND
    family = LAGRANGE

    [./InitialCondition]
      type = FunctionIC
      function = ic
    [../]
  [../]
[]

[Kernels]
  [./ie]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    preset = false
    boundary = '0 1 2 3'
    function = exact_fn
  [../]
[]

[Postprocessors]
  [./l2_err]
    type = ElementL2Error
    variable = u
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient

  l_tol = 1e-13
  start_time = 0.0
  num_steps = 20
  dt = 0.00005

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
  [../]
[]

[Outputs]
  exodus = true
  [./console]
    type = Console
    max_rows = 10
  [../]
[]

test/tests/time_integrators/actually_explicit_euler_verification/ee-2d-linear.i

[Mesh]
  type = GeneratedMesh
  dim = 2
  xmin = -1
  xmax = 1
  ymin = -1
  ymax = 1
  nx = 10
  ny = 10
  elem_type = QUAD4
[]

[Functions]
  [./ic]
    type = ParsedFunction
    value = 0
  [../]

  [./forcing_fn]
    type = ParsedFunction
    value = (x+y)
  [../]

  [./exact_fn]
    type = ParsedFunction
    value = t*(x+y)
  [../]
[]

[Variables]
  [./u]
    order = FIRST
    family = LAGRANGE

    [./InitialCondition]
      type = FunctionIC
      function = ic
    [../]
  [../]
[]

[Kernels]
  [./ie]
    type = TimeDerivative
    variable = u
  [../]

  [./diff]
    type = Diffusion
    variable = u
  [../]

  [./ffn]
    type = BodyForce
    variable = u
    function = forcing_fn
  [../]
[]

[BCs]
  [./all]
    type = FunctionDirichletBC
    variable = u
    preset = false
    boundary = '0 1 2 3'
    function = exact_fn
  [../]
[]

[Postprocessors]
  [./l2_err]
    type = ElementL2Error
    variable = u
    function = exact_fn
  [../]
[]

[Executioner]
  type = Transient

  start_time = 0.0
  num_steps = 20
  dt = 0.00005
  l_tol = 1e-12

  [./TimeIntegrator]
    type = ActuallyExplicitEuler
  [../]
[]

[Outputs]
  exodus = true
  [./console]
    type = Console
    max_rows = 10
  [../]
[]

Input Parameters
Input Files

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ActuallyExplicitEuler

Input Parameters

Optional Parameters

Advanced Parameters

Input Files