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 Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

We study the dynamics and properties of a turbulent flame, formed in thepresence of subsonic, high-speed, homogeneous, isotropic Kolmogorov-typeturbulence in an unconfined system. Direct numerical simulations are performedwith Athena-RFX, a massively parallel, fully compressible, high-order,dimensionally unsplit, reactive-flow code. A simplified reaction-diffusionmodel represents a stoichiometric H2-air mixture. The system being modeledrepresents turbulent combustion with the Damkohler number Da = 0.05 and withthe turbulent velocity at the energy injection scale 30 times larger than thelaminar flame speed. The simulations show that flame interaction withhigh-speed turbulence forms a steadily propagating turbulent flame with a flamebrush width approximately twice the energy injection scale and a speed fourtimes the laminar flame speed. A method for reconstructing the internal flamestructure is described and used to show that the turbulent flame consists oftightly folded flamelets. The reaction zone structure of these is virtuallyidentical to that of the planar laminar flame, while the preheat zone isbroadened by approximately a factor of two. Consequently, the system evolutionrepresents turbulent combustion in the thin-reaction zone regime. The turbulentcascade fails to penetrate the internal flame structure, and thus the action ofsmall-scale turbulence is suppressed throughout most of the flame. Finally, ourresults suggest that for stoichiometric H2-air mixtures, any substantial flamebroadening by the action of turbulence cannot be expected in all subsonicregimes.

The Interaction of High-Speed Turbulence with Flames: Global Properties and Internal Flame Structure