On spurious behavior of CFD simulations
- National Aeronautics and Space Administration, Moffett Field, CA (United States). Ames Research Center
- Sandia National Labs., Albuquerque, NM (United States)
- Wright Lab., Wright-Patterson AFB, OH (United States)
- Univ. of Reading (United Kingdom)
Spurious behavior in underresolved grids and/or semi-implicit temporal discretizations for four computational fluid dynamics (CFD) simulations are studied. The numerical simulations consist of (a) a 1-D chemically relaxed nonequilibrium model, (b) the direct numerical simulation (DNS) of 2-D incompressible flow over a backward facing step, (c) a loosely-coupled approach for a 2-D fluid-structure interaction, and (d) a 3-D compressible unsteady flow simulation of vortex breakdown in delta wings. Using knowledge from dynamical systems theory, various types of spurious behaviors that are numerical artifacts were systematically identified. These studies revealed the various possible dangers of misinterpreting numerical simulation of realistic complex flows that are constrained by the available computing power. In large scale computations underresolved grids, semi-implicit procedures, loosely-coupled implicit procedures, and insufficiently long time integration in DNS are most often unavoidable. Consequently, care must be taken in both computation and in interpretation of the numerical data. The results presented confirm the important role that dynamical systems theory can play in the understanding of the nonlinear behavior of numerical algorithms and in aiding the identification of the sources of numerical uncertainties in CFD.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE Assistant Secretary for Fossil Energy, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 474934
- Report Number(s):
- SAND-97-1062C; CONF-970666-2; ON: DE97005371; TRN: AHC29711%%104
- Resource Relation:
- Conference: 13. American Institute of Aeronautics and Astronautics computational fluid dynamics conference, Snowmass, CO (United States), 29 Jun - 2 Jul 1997; Other Information: PBD: [1997]
- Country of Publication:
- United States
- Language:
- English
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