The pluggable interfaces in MOOSE are called Systems. Each System provides a unique capability to help you craft your application. Below is a current list of each of the Systems:

  • Actions: Set up the problem to be solved (custom input file syntax)
  • Auxiliary Kernels: Explicit calculations that form fields
  • Auxiliary Variables: Allow explicit calculations using nonlinear variables.
  • BCs: Boundary conditions
  • Constraints: Tying degrees of freedom to each other
  • Dampers: Keep Newton's method on the right path
  • DGKernels: Discontinuous Galerkin element boundary integrals
  • DiracKernels: Point sources/sinks
  • Executioners: Control how the simulation unfolds (Transient/Steady/etc.)
  • Functions: Flexible system for creating functions of space and time
  • GeomSearch: Spatial relationships between pieces of mesh (useful for contact)
  • ICs: Initial conditions
  • Indicators: Relative error computations used for mesh adaptivity
  • InterfaceKernels: Interface physics across subdomains
  • Kernels: PDE operators representing physics
  • Markers: Select elements to refine or coarsen for mesh adaptivity
  • Materials: Compute physical coefficients needed by Kernels
  • Mesh: Read in / create geometry
  • MeshModfiers: Modify the mesh
  • MultiApps: Run multiple MOOSE-based solves/codes simultaneously in parallel
  • NodalKernels
  • Outputs: Output simulation results
  • Postprocessors: Scalar reductions of field data (integrals, averages, etc.)
  • Preconditioners: Accelerate linear convergence
  • Predictors: Accelerate nonlinear convergence by using good initial guesses
  • Splits: Advanced preconditioning capability
  • TimeIntegrators: Just like it says
  • TimeSteppers: How to advance through time
  • Transfers: Move data between MultiApps
  • UserObjects: Custom calculations that can feed any other system in MOOSE
  • Variables: Setup the unknowns for your problem
  • Controls: System for altering input parameters at runtime.
    • TimePeriods: Control active/inactive objects during a simulation.