Showing papers by "William J. Rider published in 2007"

Implicit large eddy simulation : computing turbulent fluid dynamics

Abstract: Introduction Fernando Grinstein, Len Margolin and William Rider Part I. Motivation: 1. Historical introduction Jay Boris 2. ILES for turbulent flows: a rationale Fernando Grinstein, Len Margolin and William Rider Part II. Capturing Physics with Numerics: 3. Subgrid scale modeling: issues and approaches Pierre Sagaut 4. Numerics for ILES 4a. Limiting algorithms Dimitris Drikakis, Marco Hahn, Fernando Grinstein, Carl DeVore, Christer Fureby, Mattias Liefvendahl and David Youngs 4b. Piecewise parabolic method Paul Woodward 4c. Lagrangean remap method David Youngs 4d. MPDATA Piotr Smolarkiewicz and Len Margolin 4e. Vorticity confinement John Steinhoff, Nicholas Lynn and Lesong Wang 5. Numerical regularization Len Margolin and William Rider 6. Approximate deconvolution Nikolaus Adams and J. A. Domaradzki Part III. Verification and Validation: 7. Homogeneous turbulence David Porter and Paul Woodward 8. Vortex dynamics and transition in free shear flows Fernando Grinstein 9. Symmetry bifurcation and instabilities Dimitris Drikakis 10. Incompressible wall bounded flows Christer Fureby, Mattias Liefvendahl, Urban Svennberg, Leif Persson and Tobias Persson 11. Compressible turbulent shear flows Christer Fureby and Doyle Knight 12. Studies based on vorticity confinement John Steinhoff, Nicholas Lynn, Wenren Yonghu, Meng Fan, Lesong Wang and Bill Dietz 13. Rayleigh-Taylor and Richtmyer-Meshkov mixing David Youngs Part IV. Frontier Flows: 14. Studies of geophysics Piotr Smolarkiewicz and Len Margolin 15. Studies of astrophysics David Porter and Paul Woodward 16. Complex engineering turbulent flows Niklas Alin, Magnus Berglund, Christer Fureby, Eric Lillberg and Urban Svennberg 17. Large scale urban simulations Gopal Patnaik, Fernando Grinstein, Jay Boris, Ted Young and Oskar Parmhed 18. Outlook and open research issues Fernando Grinstein, Len Margolin and William Rider.

Effective subgrid modeling from the iles simulation of compressible turbulence

Abstract: Implicit large eddy simulation (ILES) has provided many computer simula- tions with an efficient and effective model for turbulence. Thecapacity for ILES has been shown to arise from a broad class of numerical methods with specific properties producing non-oscillatory solutions using limiters that provide these methods with nonlinear stabil- ity. The use of modified equation has allowed us to understand the mechanisms behind the efficacy of ILES as a model. Much of the understanding of theILES modeling has proceeded in the realm of incompressible flows. Here, we extend this analysis to compress- ible flows. While the general conclusions are consistent with our previous findings the compressible case has several important distinctions. Like the incompressible analysis, the ILES of compressible flow is dominated by an effective self-similarity model (1, 3, 24). Here, we focus on one of these issues, the form of the effective subgrid model for the conservation of mass equations. In the mass equation, the leading order model is a self- similarity model acting on the joint gradients of density and velocity. The dissipative ILES model results from the limiter and upwind differencing resulting in effects propor- tional to the acoustic modes in the flow as well as the convective effects. We examine the model is several limits including the incompressible limit. This equation differs from the standard form found in the classical Navier-Stokes equations, but generally follows the form suggested by Brenner (5) in a modification of Navier-Stokes necessary to suc- cessfully reproduce some experimentally measure phenomena. The implications of these developments are discussed in relation to the usual turbulence modeling approaches.