Effect of the Darrieus-Landau instability on turbulent flame velocity

TL;DR

This paper investigates how the Darrieus-Landau instability affects turbulent flame velocity using a nonlinear model that accounts for turbulence and flame front properties, aligning with experimental data.

Contribution

It introduces a nonlinear equation model that incorporates both turbulence effects and intrinsic flame properties to analyze flame velocity.

Findings

Darrieus-Landau instability significantly impacts flame velocity.

Results agree with experimental data on turbulent burning.

Influence depends on turbulence scale, intensity, and density variations.

Abstract

Propagation of turbulent premixed flames influenced by the intrinsic hydrodynamic flame instability (the Darrieus-Landau instability) is considered in a two-dimensional case using the model nonlinear equation proposed recently. The nonlinear equation takes into account both influence of external turbulence and intrinsic properties of a flame front, such as small but finite flame thickness and realistically large density variations across the flame front. Dependence of the flame velocity on the turbulent length scale, on the turbulent intensity and on the density variations is investigated in the case of weak non-linearity and weak external turbulence. It is shown that the Darrieus-Landau instability influences the flamelet velocity considerably. The obtained results are in agreement with experimental data on turbulent burning of moderate values of the Reynolds number.