InterfaceKernels System

Interface kernels are meant to assist in coupling different physics across sub-domains. The most straightforward example is the case in which one wants to set the flux of a specie A in subdomain 0 equal to the flux of a specie B in subdomain 1 at the boundary between subdomains 0 and 1. In mathematical terms, we might be interested in establishing the condition:

where is the diffusion coefficient of specie in subdomain , and is the concentration of specie in subdomain . An example of this condition is shown in the MOOSE test directory; see files below:

(../moose/test/tests/interfacekernels/2d_interface/coupled_value_coupled_flux.i)

(../moose/framework/src/interfacekernels/InterfaceDiffusion.C)

(../moose/framework/include/interfacekernels/InterfaceDiffusion.h)

Interface kernels can be used to provide any general flux condition at an interface, and even more generally can be used to impose any interfacial condition that requires access to values of different variables and gradients of different variables on either side of an interface. In an input file, the user will specify at a minimum the following parameters:

  • type: The type of interface kernel to be used

  • variable: This is the "primary" variable. Note that the primary variable must exist on the same subdomain as the sideset specified in the boundary parameter. The existence of a "primary" and "secondary" or "neighbor" variable ensures that the interface kernel residual and jacobian functions get called the correct number of times. variable could be from our example above.

  • neighbor_var: The "secondary" variable. This could be from our example above.

  • boundary: The interfacial boundary between the subdomains. Note that this must be a sideset and again must exist on the same subdomain as the primary variable. The fact that this boundary is a sideset allows access to variable gradients.

For additional information about the interface kernel system, don't hesitate to contact the MOOSE Discussion forum.

Available Objects

  • Moose App
  • ADPenaltyInterfaceDiffusionA penalty-based interface condition that forcesthe continuity of variables and the flux equivalence across an interface.
  • ADVectorPenaltyInterfaceDiffusionA penalty-based interface condition that forcesthe continuity of variables and the flux equivalence across an interface.
  • InterfaceDiffusionThe kernel is utilized to establish flux equivalence on an interface for variables.
  • InterfaceEqualityThe kernel is utilized to establish equivalence on an interface for variables.
  • InterfaceReactionImplements a reaction to establish ReactionRate=k_f*u-k_b*v at interface.
  • PenaltyInterfaceDiffusionA penalty-based interface condition that forcesthe continuity of variables and the flux equivalence across an interface.
  • VectorPenaltyInterfaceDiffusionA penalty-based interface condition that forcesthe continuity of variables and the flux equivalence across an interface.
  • Tensor Mechanics App
  • ADCZMInterfaceKernelSmallStrainCZM Interface kernel to use when using the small strain kinematic formulation.
  • ADCZMInterfaceKernelTotalLagrangianCZM Interface kernel to use when using the total Lagrangian formulation.
  • CZMInterfaceKernelSmallStrainCZM Interface kernel to use when using the Small Strain kinematic formulation.
  • CZMInterfaceKernelTotalLagrangian
  • Phase Field App
  • EqualGradientLagrangeInterfaceEnforce componentwise gradient continuity between two different variables across a subdomain boundary using a Lagrange multiplier
  • EqualGradientLagrangeMultiplierLagrange multiplier kernel for EqualGradientLagrangeInterface.
  • InterfaceDiffusionBoundaryTermAdd weak form surface terms of the Diffusion equation for two different variables across a subdomain boundary
  • InterfaceDiffusionFluxMatchEnforce flux continuity between two different variables across a subdomain boundary
  • Electromagnetics App
  • ElectrostaticContactConditionInterface condition that describes the current continuity and contact conductance across a boundary formed between two dissimilar materials (resulting in a potential discontinuity). Conductivity on each side of the boundary is defined via the material properties system.
  • ParallelElectricFieldInterfaceVectorInterfaceKernel that implements the condition
  • PerpendicularElectricFieldInterfaceVectorInterfaceKernel that implements the condition

Available Actions