• Solver Fortran File: Compute2DNodalGradient.F90
• Solver Name: ElmerIce_MeshAdapt2D(Compute2DNodalGradient)
• Required Output Variable(s):
  • (1) g (dofs=2)
• Required Input Variable(s):
  • (1) v
• Optional Output Variable(s): None
• Optional Input Variable(s): None

This is a pseudo solver (i.e. it is not solving an equation). This solver compute the nodal 2D gradient vector of a variable v.

This is used for example by the mesh adaptation procedure to compute the hessian of v (Mesh Adaptation).

By default (FE consistent average = Logical True), this is done using a L²-projection on the FE mesh; If FE consistent average = False, at a given node the derivative is simply the average of the derivatives evaluated at the node in each elements sharing the node.

Solver 2
  Equation = "Nodal Gradient"
  Variable = -dofs 2 "g"
  Procedure = "ElmerIce_MeshAdapt2D" "Compute2DNodalGradient"

  Optimize Bandwidth = False

  Variable Name = string "v"
  FE consistent average = Logical True
End

Examples for anisotropic mesh adaptation can be found under [ELMER_TRUNK]/elmerice/Tests/MMG2D_Aniso1 and [ELMER_TRUNK]/elmerice/Tests/MMG2D_Aniso2, where the mesh size is adapted using 1 or 2 variables (i.e. combining metric informations), respectively.