Direct Numerical Simulations of Statistically Stationary Turbulent Premixed Flames

ABSTRACT

Direct numerical simulations (DNS) of turbulent combustion have evolved tremendously in the past decades, thanks to the rapid advances in high performance computing technology. Today’s DNS is capable of incorporating detailed reaction mechanisms and transport properties of hydrocarbon fuels, with physical parameter ranges approaching laboratory scale flames, thereby allowing direct comparison and cross-validation against laser diagnostic measurements. While these developments have led to significantly improved understanding of fundamental turbulent flame characteristics, there are increasing demands to explore combustion regimes at higher levels of turbulent Reynolds (Re) and Karlovitz (Ka) numbers, with a practical interest in new combustion engines driving towards higher efficiencies and lower emissions. The article attempts to provide a brief overview of the state-of-the-art DNS of turbulent premixed flames at high Re/Ka conditions, with an emphasis on homogeneous and isotropic turbulent flow configurations. Some important qualitative findings from numerical studies are summarized, new analytical approaches to investigate intensely turbulent premixed flame dynamics are discussed, and topics for future research are suggested.

KEYWORDS:

• Combustion regimes
• Direct numerical simulation
• Flame particle tracking
• Premixed combustion
• Turbulent flames

Acknowledgment

The authors thank Professor Jim Driscoll at the University of Michigan for sharing his recent experimental work.

Funding

The work presented in this study was sponsored by King Abdullah University of Science and Technology (KAUST) and by ISRO-IISc Space Technology Cell.

Additional information

Funding

The work presented in this study was sponsored by King Abdullah University of Science and Technology (KAUST) and by ISRO-IISc Space Technology Cell.