MaterialDerivativeTestKernel

Description

MaterialDerivativeTestKernel is a generic test Kernel that allows checking the correctness of derivative material properties using the built-in Jacobian checks in the MOOSE test harness. Its weak form is given by (\psi_i, p) where p is a material property that depends on the governing variables. MaterialDerivativeTestKernel inherits from DerivativeMaterialInterface which gives it access to functions like getMaterialPropertyDerivative and mapJvarToCvar, explained below:

  • getMaterialPropertyDerivative takes a material property name (let's call it "p") and a variable name (let's call it "u") and returns a MaterialProperty equal to the derivative of the supplied material property with respect to the supplied variable, e.g. .

  • mapJvarToCvar maps the global variable number to the kernel's coupled variable number.

This interface allows for easy and elegant construction of correct Jacobians for physics that depend on materials that are functions of governing variables.

Example Syntax

The Kernel and Material blocks below demonstrate how to utilize the DerivativeMaterialInterface capabilities in an input file.

  • Kernel block

[Kernels]
  [./test_kernel]
    type = MaterialDerivativeTestKernel
    variable = u
    args = 'u v'
    material_property = material_derivative_test_property
  [../]
  # add a dummy kernel for v to prevent singular Jacobian
  [./dummy_kernel]
    type = Diffusion
    variable = v
  [../]
[]
(test/tests/kernels/material_derivatives/material_derivatives_test.i)
  • Material block

[Materials]
  [./material_derivative_test_material]
    type = MaterialDerivativeTestMaterial
    var1 = u
    var2 = v
  [../]
[]
(test/tests/kernels/material_derivatives/material_derivatives_test.i)

MaterialDerivativeTestMaterial takes two variables, var1 and var2 as input parameters. It declares a material property with the name material_derivative_test_property. It also declares two material property derivatives that are the derivatives of material_derivative_test_property with respect to var1 and var2. In our test input file above, we assign var1 = u and var2 = v. Then as long as we pass u and v as coupled variables in the args parameter of MaterialDerivativeTestKernel, we will automatically access the correct material property derivatives in our kernel.

This kernel puts a seleted scalar (Real type) material property (material_property) in the residual vector and assembles the Jacobian using the derivatives of the material property as provided by the DerivativeMaterialInterface.

Input Parameters

  • variableThe name of the variable that this Kernel operates on

    C++ Type:NonlinearVariableName

    Options:

    Description:The name of the variable that this Kernel operates on

  • argsList of variables the material property depends on

    C++ Type:std::vector

    Options:

    Description:List of variables the material property depends on

  • material_propertyName of material property for which derivatives are to be tested.

    C++ Type:MaterialPropertyName

    Options:

    Description:Name of material property for which derivatives are to be tested.

Required Parameters

  • derivativeSelect derivative to test derivatives of (leave empty for checking derivatives of the original material property)

    C++ Type:std::vector

    Options:

    Description:Select derivative to test derivatives of (leave empty for checking derivatives of the original material property)

  • blockThe list of block ids (SubdomainID) that this object will be applied

    C++ Type:std::vector

    Options:

    Description:The list of block ids (SubdomainID) that this object will be applied

Optional Parameters

  • enableTrueSet the enabled status of the MooseObject.

    Default:True

    C++ Type:bool

    Options:

    Description:Set the enabled status of the MooseObject.

  • save_inThe name of auxiliary variables to save this Kernel's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

    C++ Type:std::vector

    Options:

    Description:The name of auxiliary variables to save this Kernel's residual contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

  • 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

    Options:

    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.

  • 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.

  • seed0The seed for the master random number generator

    Default:0

    C++ Type:unsigned int

    Options:

    Description:The seed for the master random number generator

  • diag_save_inThe name of auxiliary variables to save this Kernel's diagonal Jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

    C++ Type:std::vector

    Options:

    Description:The name of auxiliary variables to save this Kernel's diagonal Jacobian contributions to. Everything about that variable must match everything about this variable (the type, what blocks it's on, etc.)

  • implicitTrueDetermines whether this object is calculated using an implicit or explicit form

    Default:True

    C++ Type:bool

    Options:

    Description:Determines whether this object is calculated using an implicit or explicit form

Advanced Parameters

  • vector_tagsnontimeThe tag for the vectors this Kernel should fill

    Default:nontime

    C++ Type:MultiMooseEnum

    Options:nontime time

    Description:The tag for the vectors this Kernel should fill

  • extra_vector_tagsThe extra tags for the vectors this Kernel should fill

    C++ Type:std::vector

    Options:

    Description:The extra tags for the vectors this Kernel should fill

  • matrix_tagssystemThe tag for the matrices this Kernel should fill

    Default:system

    C++ Type:MultiMooseEnum

    Options:nontime system

    Description:The tag for the matrices this Kernel should fill

  • extra_matrix_tagsThe extra tags for the matrices this Kernel should fill

    C++ Type:std::vector

    Options:

    Description:The extra tags for the matrices this Kernel should fill

Tagging Parameters

Input Files