INNER CUTOFF SCALE OF FLAME SURFACE WRINKLING IN TURBULENT PREMIXED FLAMES

The inner cutoff represents the smallest scale for the interaction of turbulent eddies with the premixed flame front. The nondimensional inner cutoff has been shown to scale with Karlovitz number, Ka(beta), where beta is -1/2. Three experimental data sets, with available statistical information, strongly agree with this scaling. However, the five data sets, two without experimental error statistics, seem to favor beta = -1/3, in accordance with the direct numerical simulation results. The inner cutoff expressions reported in literature, obtained through experimental data, numerical data, or physical reasoning, have been evaluated by comparing with five experimental data sets reported recently. It has been shown that the Gibson scale, which was proposed as the inner cutoff and asserts an inverse square dependence on Karlovitz number, does not show any agreement with the experimental data or direct numerical simulation results.