English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

We study the sub-grid scale characteristics of a vorticity-transport-basedapproach for large-eddy simulations. In particular, we consider amulti-dimensional upwind scheme for the vorticity transport equations andestablish its properties in the under-resolved regime. The asymptotic behaviorof key turbulence statistics of velocity gradients, vorticity, and invariantsis studied in detail. Modified equation analysis indicates that dissipation canbe controlled locally via non-linear limiting of the gradient employed for thevorticity reconstruction on the cell face such that low numerical diffusion isobtained in well-resolved regimes and high numerical diffusion is realized inunder-resolved regions. The enstrophy budget highlights the remarkable abilityof the truncation terms to mimic the true sub-grid scale dissipation anddiffusion. The modified equation also reveals diffusive terms that are similarto several commonly employed sub-grid scale models including tensor-gradientand hyper-viscosity models. Investigations on several canonical turbulence flowcases show that large-scale features are adequately represented and remainconsistent in terms of spectral energy over a range of grid resolutions.Numerical dissipation in under-resolved simulations is consistent and can becharacterized by diffusion terms discovered in the modified equation analysis.A minimum state of scale separation necessary to obtain asymptotic behavior ischaracterized using metrics such as effective Reynolds number and effectivegrid spacing. Temporally-evolving jet simulations, characterized by large-scalevortical structures, demonstrate that high Reynolds number vortex-dominatedflows are captured when criteria is met and necessitate diffusive non-linearlimiting of vorticity reconstruction be employed to realize accuracy inunder-resolved simulations.

Sub-grid scale characterization and asymptotic behavior of multi-dimensional upwind schemes for the vorticity transport equations