Large eddy simulation of turbulent premixed combustion using tabulated detailed chemistry and presumed probability density function

ABSTRACT

A method of chemistry tabulation combined with presumed probability density function (PDF) is applied to simulate piloted premixed jet burner flames with high Karlovitz number using large eddy simulation. Thermo-chemistry states are tabulated by the combination of auto-ignition and extended auto-ignition model. To evaluate the predictive capability of the proposed tabulation method to represent the thermo-chemistry states under the condition of different fresh gases temperature, a-priori study is conducted by performing idealised transient one-dimensional premixed flame simulations. Presumed PDF is used to involve the interaction of turbulence and flame with beta PDF to model the reaction progress variable distribution. Two presumed PDF models, Dirichlet distribution and independent beta distribution, respectively, are applied for representing the interaction between two mixture fractions that are associated with three inlet streams. Comparisons of statistical results show that two presumed PDF models for the two mixture fractions are both capable of predicting temperature and major species profiles, however, they are shown to have a significant effect on the predictions for intermediate species. An analysis of the thermo-chemical state-space representation of the sub-grid scale (SGS) combustion model is performed by comparing correlations between the carbon monoxide mass fraction and temperature. The SGS combustion model based on the proposed chemistry tabulation can reasonably capture the peak value and change trend of intermediate species. Aspects regarding model extensions to adequately predict the peak location of intermediate species are discussed.

KEYWORDS:

• Piloted premixed jet burner
• well-stirred reactor regime
• large eddy simulation
• tabulated chemistry
• presumed probability density function

Acknowledgments

The authors would like to acknowledge the funding of the Program (Grant Nos. 51176178, 91441117 and 91441202), and the Key Program (Grant No. 50936005) of National Natural Science Foundation of China. We want to express our gratitude to Prof. Assaad Masri for sharing the experimental data. The numerical calculations in this paper have been done on the supercomputing system in the Supercomputing Center of University of Science and Technology of China.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors would like to acknowledge the funding of the Program [grant no. 51176178], [grant no. 91441117], [grant no. 91441202], and the Key Program [grant no. 50936005] of National Natural Science Foundation of China.