Skip to main content
NASA Advanced Supercomputing (NAS) Division World-class modeling, simulation, and supercomputing in support of the NASA mission

Overset Mesh Generation for the High-Lift Common Research Model

AMS Seminar Series

Speaker: William Chan, NAS Computational Aerosciences Branch, NASA Ames Research Center

Presentation

Seminar Slide Deck (PDF-9.3MB)

Abstract

Structured overset meshes for the High-Lift Common Research Model (CRM) have been generated to support the 1st AIAA Geometry and Mesh Generation Workshop and the 3rd AIAA High-Lift Prediction Workshop. Four grid systems at the coarse, medium, fine, and extra-fine grid resolutions have been created for a full flap gap case, and a grid system at the medium resolution level has been created for a partially-sealed flap gap case. Algebraic and hyperbolic methods are applied in creating surface and volume grids using NASA's Chimera Grid Tools (CGT) software package. Body-fitted curvilinear volume grids are used to resolve the viscous flow near the geometry surface. Special clustered regions are utilized for accurate wake capture which is crucial in high-lift flow field computations. These grids are embedded in multiple stretched off-body Cartesian grids of telescoping resolutions that extend to the far field. Two different methods for performing domain connectivity are compared. These include a distance-based hole-cut approach in NASA's Chimera Components Connectivity Program (C3P) and the standard X-rays hole-cut approach in NASA's OVERFLOW-DCF software. Best practices in domain decomposition, grid point distribution, mesh connectivity, and grid generation process management are discussed. Various lessons learned in grid quality checks and creation of a family of grid systems at different resolutions are also presented. Suggestions are given for further improvements in the current grid generation process and grid diagnostic tools.

Biography

William Chan is a research scientist in the Computational Aerosciences Branch at NASA Ames Research Center. His primary interest is on the development of algorithms and software for overset grid pre-processing and post-processing. He is the principal developer of many of the modules in the Chimera Grid Tools software package which has been distributed to over 800 organizations in U.S. government laboratories, industry and universities. Since the beginning of his career at NASA Ames, he has supported numerous NASA projects. These include high fidelity CFD simulations of the Space Shuttle Launch Vehicle, multiple subsonic and supersonic fixed-wing, and rotory-wing vehicles, various turbo pumps and liquid rocket sub-systems, and a variety of space launch vehicles from the Constellation and Space Launch Systems Programs. His work has been recognized through the NASA Exceptional Achievement and Exceptional Service Medals, and various Technology Transfer awards. William obtained his B.S. in Mathematics from Southampton University in the U.K., and his M.S. and Ph.D. from the Mechanical Engineering Department of Stanford University.