2.1 Motivation

• Was developing 2D Lagrangian-mesh SP_N radflow package
  • each accelerated iteration requires numerous diffusion solves
• built on top of Morel diffusion package
  • $\sim$ 3N_cells unknowns
  • non-standard stencil
    • 5-pt. stencil for cell-center equations
    • 7-pt. stencil for cell-edge equations
  • nonsymmetric linear system
    • recent work indicates symmetric formulation possible
• custom preconditioner
  • eliminate edge unknowns algebraically to obtain standard 5-pt. stencil (symmetric)
  • single V-cycle of multigrid (Joel Dendy)