Modeling ignition and chemical structure of partially premixed turbulent flames using tabulated chemistry
- IFP, 1 et 4 rue Bois Preau, F92852, Rueil Malmaison (France)
- EM2C, UPR 288 CNRS, Ecole Centrale Paris, F92295, Chatenay Malabry (France)
Correctly reproducing the autoignition and the chemical composition of partially premixed turbulent flames is a challenge for numerical simulations of industrial applications such as diesel engines. A new model DF-PCM (diffusion flame presumed conditional moment) is proposed based on a coupling between the FPI (flame prolongation of ILDM) tabulation method and the PCM (presumed conditional moment) approach. Because the flamelets used to build the table are laminar diffusion flames, DF-PCM cannot be used for industrial applications like Diesel engines due to excessive CPU requirements. Therefore two new models called AI-PCM (autoignition presumed conditional moment) and ADF-PCM (approximated diffusion flames presumed conditional moment) are developed to approximate it. These models differ from DF-PCM because the flamelet libraries used for the table rely on PSR calculations. Comparisons between DF-PCM, AI-PCM, and ADF-PCM are performed for two fuels, n-heptane, representative of diesel fuels, and methane, which does not exhibit a ''cool flame'' ignition regime. These comparisons show that laminar diffusion flames can be approximated by flamelets based on PSR calculations in terms of autoignition delays and steady state profiles of the progress variable. Moreover, the evolution of the mean progress variable of DF-PCM can be correctly estimated by the approximated models. However, as discussed in this paper, errors are larger for CO and CO{sub 2} mass fractions evolutions. Finally, an improvement to ADF-PCM, taking into account ignition delays, is proposed to better reproduce the ignition of very rich mixtures. (author)
- OSTI ID:
- 20999329
- Journal Information:
- Combustion and Flame, Vol. 152, Issue 1-2; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBON DIOXIDE
CARBON MONOXIDE
AUTOIGNITION
DIESEL ENGINES
LAMINAR FLAMES
COMPARATIVE EVALUATIONS
DIFFUSION
HEPTANE
METHANE
SIMULATION
COMBUSTION
MIXTURES
CHEMICAL COMPOSITION
STEADY-STATE CONDITIONS
DATA COVARIANCES
TURBULENCE
MATHEMATICAL MODELS