Measurement techniques for turbulent flames: from time-resolved thermocouples to flamelet images

摘要

In studies of premixed turbulent comustion, a reaction progress variable, c, is defined such that c is 0 in reactants and 1 in products. In turn, an equation for the Favre averaged progress variable, c-tilde is developed containing terms for mean product formation, , mean flow convectionand turbulent and molecular transport. The integral of <2> along a line perpendicular to c-tilde constant surfaces defines the burning rate integral, B_T, an unamgiuous measure of the overal premixed turbulent combustion rate. For a range of condtioins, instantaneous reaction is confined to thin sheet-like zones, flamelets, and for this condition is proportional to the mean flamelet sheet surface-to-volume ratio, sum.