Precursors to blowout in a turbulent combustor based on recurrence quantification

摘要

Combustion systems with turbulent reactive flow exhibit intermittency prior to flame blowout. In this experimental study using a dump combustor with a bluff-body stabilized flame, we characterize the variation of this intermittent behavior as we approach blowout using recurrence quantification analysis and thereby provide viable precursors to an impending blowout. We observe that as blowout is approached, the system exhibits increased aperiodicity in oscillations. Using statistical quantities estimated from the recurrence plots, such as recurrence rate, trapping time and entropy of diagonal lines, we characterize the variations in the dynamic characteristics of the pressure fluctuations as the lean blowout is approached. Further, we suggest a method of recurrence quantification analysis that is computationally less expensive and hence more suitable for online prognosis of dynamic transitions in a turbulent combustor.