Numerical modeling of turbulent premixed flames in the thin-reaction-zonesregime

Authors
Citation
Ww. Kim et S. Menon, Numerical modeling of turbulent premixed flames in the thin-reaction-zonesregime, COMB SCI T, 160, 2000, pp. 119-150
Citations number
40
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Mechanical Engineering
Journal title
COMBUSTION SCIENCE AND TECHNOLOGY
ISSN journal
0010-2202 → ACNP
Volume
160
Year of publication
2000
Pages
119 - 150
Database
ISI
SICI code
0010-2202(2000)160:<119:NMOTPF>2.0.ZU;2-H
Abstract
A new flamelet model has been developed for large-eddy simulation of turbul ent premixed combustion in the thin-reaction-zones regime. In this regime o f turbulent combustion, turbulent eddies smaller than the flame thickness e xist and this small-scale turbulence disturbs the flame structure. Recent e xperimental observations show that turbulence interacts mostly with the che mically inert preheat zone while the thin reaction zone of the flame where all chemical processes occur remains unchanged. Therefore, flamelet models can be extended to this regime. The present model accounts for the differen t type of interactions between the flame and turbulence of different scales . The large-scale (larger than the flame thickness) turbulence increases th e turbulent burning velocity by wrinkling the flame. On the other hand, the small-scale (smaller than the flame thickness) turbulence modifies the lam inar flame propagation by enhancing the intensity of transport processes wi thin the preheat zone. The developed model has been validated by carrying o ut a posteriori tests using a realistic gas turbine combustor problem. Comp arisons with experimental data and conventional thin-flame model simulation s show that the new model can significantly improve the predictions.