Large-eddy simulation of H₂–air auto-ignition using tabulated detailed chemistry

Abstract

Large-eddy simulation (LES) of an igniting turbulent hydrogen/air jet for which experimental data are available is reported. A sub-grid scale closure is proposed that is based on a tabulation of detailed chemistry combined with a presumed probability density function, to be implemented into a fully compressible LES solver. The simulations are performed in a frame moving with the mean flow. The obtained results are shown to reproduce the experimental findings in terms of ignition length. A dynamic closure is used for the unknown sub-grid scale (SGS) scalar dissipation rate of mixture fraction and the sensitivity of the chemical response to SGS modelling is studied.

Keywords:

• large-eddy simulation
• auto-ignition
• tabulated chemistry
• nonpremixed turbulent flame

Acknowledgement

The authors would like to express their gratitude to professor E. Mastorakos from Cambridge University (UK) for kindly providing the experimental results and for many helpful discussions.