Direct numerical simulation of heat release and NOx formation in turbulent nonpremixed flames

摘要: Attempts to use complex chemistry and transport in direct numerical simulations (DNS) of premixed combustion (even for kinetically simple systems, such as H{sub 2}/air CH{sub 4}/air) often result excessive needs memory CPU time. This paper presents a methodology (integrated [ICC]) capable integrating effects into DNS while maintaining computational efficiency. The includes the limited number species reactions with parameters which are derived match flame properties. It is illustrated through four-step reaction mechanism appropriate stoichiometric methane/air flame, compares favorably predictions detailed GRI 2.11 mechanism. proposed scheme one methane oxidation, thermal, Fenimore, nonpremixed reburn chemical NO{sub x} routes. kinetic hydrocarbon oxidation were determined by matching laminar burning velocity adiabatic temperature, main reactants concentrations, extinction strain rates both (steady) (steady unsteady) strained flames. three steps corresponding profiles obtainedmore » diffusion flames 2.11. Finally, this was used two- three-dimensional turbulent assess validity flamelet approaches. While approaches found perform well heat release, their extension formation appears be not successful because existence compressed zones where products accumulate increase No{sub production.« less