NodalKernels System
Nodal kernels are used to solve equations that strictly belong on a node. Some examples include:
solving ordinary differential equations at every node. The following
NodalKernelswere implemented for that purpose: - ConstantRate - TimeDerivativeNodalKernel - UserForcingFunctionNodalKernelbounding a nodal variable's value at nodes. The following
NodalKernelswere implemented for that purpose: - LowerBoundNodalKernel - UpperBoundNodalKernelassigning mass to nodes instead of elements, as performed in the SolidMechanics module (see NodalGravity for example)
Even though we are not using an elemental quadrature in nodal kernels, Variables values should still be accessed at the index _qp (=0) for consistency with other kernels' code.
Nodal kernels may be block and boundary restricted. Naturally for boundary restriction, the nodal kernel is only defined on the nodes that are part of a boundary. For block restriction, all nodes that are part of elements in a block are considered.
Available Objects
- Moose App
- ConstantRateComputes residual or the rate in a simple ODE of du/dt = rate.
- CoupledForceNodalKernelAdds a force proportional to the value of the coupled variable
- LowerBoundNodalKernelUsed to prevent a coupled variable from going below a lower bound
- PenaltyDirichletNodalKernelEnforces a Dirichlet boundary condition in a weak sense by penalizing differences between the current solution and the Dirichlet value on nodesets.
- ReactionNodalKernelImplements a simple consuming reaction term at nodes
- TimeDerivativeNodalKernelForms the contribution to the residual and jacobian of the time derivative term from an ODE being solved at all nodes.
- UpperBoundNodalKernelUsed to prevent a coupled variable from going above a upper bound
- UserForcingFunctionNodalKernelResidual contribution to an ODE from a source function acting at nodes.
Available Actions
- Moose App
- AddNodalKernelActionAdd a NodalKernel object to the simulation.