Accession Number : ADA337939

Title :   Unstructured Grid Assessment for Viscous Flow Simulations

Descriptive Note : Final rept 1 Jul 96-31 Jul 97

Corporate Author : MCDONNELL DOUGLAS CORP ST LOUIS MO

Personal Author(s) : Michael, T. R.

PDF Url : ADA337939

Report Date : JUL 1997

Pagination or Media Count : 90

Abstract : A systematic assessment of the strengths and weaknesses of three viscous flowfield simulation methods for unstructured grids has been performed. The methods evaluated represent the primary viscous unstructured griding approaches currently in use including anisotropic tetrahedral, zonal hybrid (hexahedral/tetrahedral), and grids containing a mixture of cell types. The strengths and weaknesses of each method have been identified and grid resolution guidelines have been developed through a systematic study of the flow fields about a flat plate and ONERA M6 wing. Run conditions were selected to provide comparisons of a wide variety of flow field features including transonic and separated flows. Solutions are compared with theoretical and experimental data, and computational requirements of the three methods are compared to provide a relative evaluation of each method's accuracy and efficiency. Each of the unstructured grid approaches was found to provide adequate solution accuracy provided sufficient grid resolution and quality is employed. The zonal hybrid approach was found to provide the best solution computation efficiency at the expense of a long grid generation cycle time. The tetrahedral approach provided the fastest grid generation cycle time and the mixed cell approach provides the most flexibility.

Descriptors :   *SIMULATION, *GRIDS, *VISCOUS FLOW, RESOLUTION, COMPUTATIONAL FLUID DYNAMICS, FLOW FIELDS, PLATES, HYBRID SYSTEMS, INSTRUCTIONS, FLOW SEPARATION.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE