Development of a quadtree based agglomeration method for a multigrid viscous flow solver on unstructured grids

Mahmutyazicioglu E., TUNCER İ. H. , Aksel H.

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition, Orlando, FL, United States Of America, 4 - 07 January 2010 identifier

  • Publication Type: Conference Paper / Full Text
  • Volume:
  • City: Orlando, FL
  • Country: United States Of America


In this study, a new cell agglomeration technique is developed and applied to 1st and 2nd order inviscid/viscous multigrid flow solutions on unstructured/hybrid grids. The grid coarsening required by the multigrid scheme is achieved by agglomerating the unstructured/hybrid cells based on their distribution on a quadtree data structure. The paper presents the coarsening strategy and the multigrid adaptation on inviscid/viscous 2D solutions over a NACA 0012 airfoil section. It is shown that, the quadtree based agglomeration and grid coarsening provides well defined, nested, body fitted coarse grid with optimum aspect ratio cells at all coarse grid levels. In the cases studies, it is observed that, the multigrid flow solutions obtained in this study provide convergence accelerations about 5 to 36 times for low speed inviscid flows and in a range of 3.5 to 71 fold for viscous flows. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.