STEADY RELAXATION METHODS FOR UNSTRUCTURED MULTIGRID EULER AND NAVIER-STOKES SOLUTIONS

This study focuses on the unstructured-mesh multi-grid computation of two-dimensional, steady, transonic hows governed by the Euler or Navie r-Stokes equations (in the laminar, low-Reynolds number regime). The c entral question is the construction of an algorithm of truly O(N) comp lexity for second-order accurate schemes. This is achieved either by t he ''first-order/second-order'' Defect-Correction process, or directly by a fully ''second-order'' approach. Relations between levels are co ntrolled by a coarsening method introduced by Guillard. This work atte mpts to follow the available theoretical facts to build several strate gies that are then evaluated for a set of airfoil flows.