Premixed Turbulent Flames

Since the early days of research into premixed turbulent flames, turbulent burning velocity or flame speed was in the focus of numerous experimental, theoretical, and numerical studies. In the paper entitled “Determination of the burning velocity domain of a statistically stationary turbulent premixed flame in presence of counter-gradient transport,” the classical academic problem of the burning velocity in a fully developed statistically stationary, planar, and one-dimensional turbulent flame is theoretically analyzed in order to investigate the influence of countergradient scalar transport (i.e., transport of combustion products towards the burned side of the flame, caused by pressure gradient induced by the heat release) on the burning velocity. In the paper entitled “Effects of turbulent Reynolds number on the displacement speed statistics in the thin reaction zones regime of turbulent premixed combustion,” a DNS database obtained from premixed turbulent flames characterized by different Reynolds numbers is analyzed in order to investigate statistical characteristics of the instantaneous flame front (its local displacement speed, surface density, curvature, and strain rate) as well as relations between these statistical characteristics and the influence of the Reynolds number on them.