Validation of Computational Fluid Dynamics Simulations for Realistic Flows (Preprint)
Abstract
Strategies used to verify and validate computational fluid dynamics (CFD) calculations are described via case studies of realistic flow simulations, each representing a complex flow physics and complex geometry. Critical areas of importance to validation of a calculation are pointed out through various high fidelity physics- and engineering-based simulations. These areas include the physical model, conceptual model, boundary conditions, initial conditions, geometry, grid density and distribution, turbulence model, and numerical dissipation. Appropriate selection and exercise of the above items depend upon thorough understanding of the physics of the problem and require considerable experience on addressing them utilizing CFD codes. The cases presented include the most frequently encountered flow features of separation, swirl and rotation as observed in engineering applications such as aircraft gas combustors and turbomachinery. Each simulation considers the salient physical features involved and resolves them to the level required by the purposes for which they are being used. In many of the simulations presented, unstructured grids and parallel computing are used to minimize the overall time needed to achieve a numerical solution. In these cases, the numerical scheme incorporated allows use of a large number (thousands) of processors in parallel, to shorten the solution time and to provide speed-ups that do not deteriorate with the addition of more processors. Verification studies compare the exact analytical solutions with those obtained using various numerical schemes. In these studies preservation of a vortex convecting through a calculation domain is used to assess the numerical accuracy of time-dependent numerical schemes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2007
- Accession Number
- ADA475793
Entities
People
- Farhad Davoudzadeh
Organizations
- Air Force Research Laboratory