CoupledODETimeDerivative

Residual contribution of ODE from the time derivative of a coupled variable.

The CoupledODETimeDerivative is similar to the ODETimeDerivative scalar kernel, except that the derivative acts on a different variable than the ODE is solved for.

Example input syntax

In this example, the scalar variables f and f_times_mult are the solutions to the coupled ODE problem:

var element = document.getElementById("moose-equation-3bc15ab1-6624-4212-a4ec-b79e3960fc0f");katex.render("\\dfrac{d f\\_times\\_mult}{d t} -1 = 0", element, {displayMode:true,throwOnError:false});

var element = document.getElementById("moose-equation-7aac3e45-4527-4fed-8007-d858704fbdfb");katex.render("f\\_times\\_mult -f * g = 0", element, {displayMode:true,throwOnError:false});

The time derivative term for the first equation is added using a CoupledODETimeDerivative scalar kernel, as the first equation is set to have f as its nonlinear variable, even though f does not appear in it!

[ScalarKernels]
  [./dT]
    type = CoupledODETimeDerivative
    variable = f
    v = f_times_mult
  [../]

  [./src]
    type = ParsedODEKernel
    variable = f
    expression = '-1'
  [../]

  [./f_times_mult_1]
    type = ParsedODEKernel
    variable = f_times_mult
    expression = 'f_times_mult'
  [../]

  [./f_times_mult_2]
    type = ParsedODEKernel
    variable = f_times_mult
    expression = '-f * g'
    coupled_variables = 'f g'
  [../]
[]

Input Parameters

vCoupled variable.
C++ Type:std::vector<VariableName>
Unit:(no unit assumed)
Controllable:No
Description:Coupled variable.
variableThe name of the variable that this residual object operates on
C++ Type:NonlinearVariableName
Unit:(no unit assumed)
Controllable:No
Description:The name of the variable that this residual object operates on

Required 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>
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
Controllable:No
Description:The extra tags for the vectors this Kernel should fill
matrix_tagssystem timeThe tag for the matrices this Kernel should fill
Default:system time
C++ Type:MultiMooseEnum
Unit:(no unit assumed)
Options:nontime, system, time
Controllable:No
Description:The tag for the matrices this Kernel should fill
vector_tagstimeThe tag for the vectors this Kernel should fill
Default:time
C++ Type:MultiMooseEnum
Unit:(no unit assumed)
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>
Unit:(no unit assumed)
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
Unit:(no unit assumed)
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
Unit:(no unit assumed)
Controllable:No
Description:Determines whether this object is calculated using an implicit or explicit form
seed0The seed for the master random number generator
Default:0
C++ Type:unsigned int
Unit:(no unit assumed)
Controllable:No
Description:The seed for the master random number generator
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
Unit:(no unit assumed)
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/test/tests/kernels/ode/coupled_ode_td.i)

[Mesh]
  type = GeneratedMesh
  dim = 1
  xmin = 0
  xmax = 1
  nx = 1
[]


[Variables]
  [./f]
    family = SCALAR
    order = FIRST
    initial_condition = 1
  [../]
  [./f_times_mult]
    family = SCALAR
    order = FIRST
    initial_condition = 1
  [../]
[]

[ScalarKernels]
  [./dT]
    type = CoupledODETimeDerivative
    variable = f
    v = f_times_mult
  [../]

  [./src]
    type = ParsedODEKernel
    variable = f
    expression = '-1'
  [../]

  [./f_times_mult_1]
    type = ParsedODEKernel
    variable = f_times_mult
    expression = 'f_times_mult'
  [../]

  [./f_times_mult_2]
    type = ParsedODEKernel
    variable = f_times_mult
    expression = '-f * g'
    coupled_variables = 'f g'
  [../]
[]

[AuxVariables]
  [./g]
    family = SCALAR
    order = FIRST
  [../]
[]

[Functions]
  [./function_g]
    type = ParsedFunction
    expression = '(1 + t)'
  [../]
[]

[AuxScalarKernels]
  [./set_g]
    type = FunctionScalarAux
    function = function_g
    variable = g
    execute_on = 'linear initial'
  [../]
[]

[Executioner]
  type = Transient
  dt = 1
  num_steps = 3
  nl_abs_tol = 1e-9
[]

[Outputs]
  csv = true
[]

Example input syntax
Input Parameters