Importance of the Darrieus-Landau instability for strongly corrugated turbulent flames

The renormalization ideas of self-similar dynamics of a strongly turbulent flame front are applied to the case of a flame with realistically large thermal expansion of the burning matter. In that case a flame front is corrugated both by the external turbulence and by the intrinsic flame instability (the Darrieus-Landau instability). The analytical formulas for the velocity of flame propagation are obtained. It is demonstrated that the flame instability is of principal importance when the maximal hydrodynamic length scale is much larger than the cutoff wavelength of the instability, provided the turbulent intensity is not too high.