“…Here, Ka is a Karlovitz number; τ f = δ L /S L , S L , and δ L = (T b − T u )/ max{|dT /dx|} are the laminar flame time scale, speed, and thickness, respectively; T is the temperature; subscripts u and b designate unburned reactants and burned products; max{ω T D (k)} is the maximum growth rate of TD instability (dependence of the instability growth rate ω T D on the instability wavenumber k has a bell-like shape [43,44,45,46,47,48], as discussed in the next section); and τ K is Kolmogorov time scale, which characterizes the order of magnitude of the highest velocity gradients generated by the smallest-scale turbulent eddies [12,49,50]. Similar criteria of importance of DL instability in turbulent flows was earlier introduced using the same reasoning [19], as well as other reasoning [51,52], and results of subsequent numerical [53,54,55,56] and experimental [57] studies qualitatively supported those criteria by indicating a minor role played by DL instability under conditions of sufficiently intense turbulence.…”