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Modelling and Simulation in Engineering
Volume 2011, Article ID 217326, 9 pages
http://dx.doi.org/10.1155/2011/217326
Research Article

An Initial Investigation of Adjoint-Based Unstructured Grid Adaptation for Vortical Flow Simulations

Aeronautics Computing Technique Research Institute (ACTRI), P.O. Box 90, Xi'an 710068, China

Received 6 October 2010; Accepted 19 January 2011

Academic Editor: Guan Yeoh

Copyright © 2011 Li Li. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A computational fluid dynamics (CFDs) method utilizing unstructured grid technology has been employed to compute vortical flow around a 6 5 delta wing with sharp leading edge, which is specially known as the geometry of the second international vortex flow experiment (VFE-2). In VFE-2, 6 5 delta wings with different leading edges had been broadly investigated by experiments, which resulted in a special database for CFDs codes validation. The emphasis of this paper is to investigate the effectiveness of an adjoint-base grid adaptation method for unstructured grid in capturing concentrated vortices generated at sharp edges or flow separation lines of lifting surfaces flying at high angles of attack. Earlier experiences in vortical flow simulations had indicated that the vortex behavior is highly dependent on the local grid resolution both on body surface and space. The adjoint-based adaptation method used here is hoped to save grid points with a reasonable grid resolution for vortical flow simulations. The basic idea is to construct a new adaptive sensor in a grid adaptation process with the intent to tell where the elements should be smaller or larger by introducing an adjoint formulation to relate the estimated functional error to local residual errors of both the primal and adjoint solutions.