AuxVariables System

  • The auxiliary system's purpose is to allow explicit calculations using nonlinear variables.

  • These values can be used by kernels, BCs and material properties.

    • Just couple to them as if they were a nonlinear variable.

  • They will also come out in the output file... useful for viewing things you don't solve for (e.g. velocity).

  • Auxiliary variables currently come in two flavors:

    • Element (constant or higher order monomials)

    • Nodal (linear Lagrange)

  • When using element auxiliary variables:

    • You are computing average values per element (constant) or Cholesky solve.

    • You can couple to nonlinear variables and both element and nodal auxiliary variables.

  • When using nodal auxiliary variables:

    • You are computing values at nodes.

    • You can only couple to nonlinear variables and other nodal auxiliary variables.

  • Auxiliary variables have "old" states just like nonlinear variables.

Further AuxVariable documentation