A mass, energy, enstrophy and vorticity conserving (MEEVC) mimetic   spectral element discretization for the 2D incompressible Navier-Stokes   equations
  In this work we present a mimetic spectral element discretization for the 2D incompressible Navier-Stokes equations that in the limit of vanishing dissipation exactly preserves mass, kinetic energy, enstrophy and total vorticity on unstructured grids. The essential ingredients to achieve this are: (i) a velocity-vorticity formulation in rotational form, (ii) a sequence of function spaces capable of exactly satisfying the divergence free nature of the velocity field, and (iii) a conserving time integrator. Proofs for the exact discrete conservation properties are presented together with numerical test cases on highly irregular grids. 
Artur Palha, Marc Gerritsma
math.NA physics.flu-dyn