Generation of non-isotropic unstructured grids via directional enrichment

International Journal for Numerical Methods in Engineering, John Wiley, Vol 49, Num 1, pp.219-232, September 10-20 2000

MESHING
RESEARCH
CORNER

Special Edition on Unstructured Mesh Generation
International Journal for Numerical Methods in Engineering, Vol 49 Number 1-2, 10-20 September 2000

Correspondence to: Rainald Lohner, Institute for Computational Science and informatics, M.S. 4C7, George Mason University, Fairfax, VA 22030-4444, U.S.A.
E-mail: lohner@rossini.gmn.edu

Abstract
A procedure for the generation of highly stretched grids suitable for Reynolds-averaged Navier-Stokes (RANS) calculations is presented. In a first stage, an isotropic (Euler) mesh is generated. In a second stage, this grid is successively enriched with points in order to achieve highly stretched elements. The element reconnection is carried out using a constrained Delaunay approach. Points are introduced from the regions of lowest stretching towards the regions of highest stretching. The procedure has the advantages of not requir- ing any type of surface recovery, not requiring extra passes or work to mesh concave ridges/comers, and guarantees a final mesh, an essential requirement for industrial environments. Given that point placement and element quality are higWy dependent for the Delaunay procedure, special procedures were developed in order to obtain optimal point placement.