Augmented reduced order models for turbulence

Journal Article · Thu Sep 29 00:00:00 UTC 2022 · Frontiers in Physics

DOI: https://doi.org/10.3389/fphy.2022.905392 · OSTI ID:1890242

Kaneko, Kento; Fischer, Paul

The authors introduce an augmented-basis method (ABM) to stabilize reduced-order models (ROMs) of turbulent incompressible flows. The method begins with standard basis functions derived from proper orthogonal decomposition (POD) of snapshot sets taken from a full-order model. These are then augmented with divergence-free projections of a subset of the nonlinear interaction terms that constitute a significant fraction of the time-derivative of the solution. The augmenting bases, which are rich in localized high wavenumber content, are better able to dissipate turbulent kinetic energy than the standard POD bases. Several examples illustrate that the ABM significantly out-performs L ² -, H ¹ - and Leray-stabilized POD ROM approaches. The ABM yields accuracy that is comparable to constraint-based stabilization approaches yet is suitable for parametric model-order reduction in which one uses the ROM to evaluate quantities of interests at parameter values that differ from those used to generate the full-order model snapshots. Several numerical experiments point to the importance of localized high wavenumber content in the generation of stable, accurate, and efficient ROMs for turbulent flows.

• Sponsoring Organization: USDOE
• Grant/Contract Number: NE0008780
• OSTI ID: 1890242
• Journal Information: Frontiers in Physics, Journal Name: Frontiers in Physics Vol. 10; ISSN 2296-424X
• Publisher: Frontiers Media SACopyright Statement
• Country of Publication: Switzerland
• Language: English