On the Role of Large and Small-Scale Structures in Combustion Control

摘要: Abstract Experiments were performed to actively control combustion between coaxial air and fuel jets. The objective was initiate the as close possible flameholder surface maintain uniform in entire mixing region. Forcing applied both streams. at different frequencies amplitudes. jet excited its preferred mode frequency while forced higher harmonics order trigger amplify initial instabilities of jet. Nonreacting tests showed that combined forcing promoting an earlier transition small-scale turbulence nozzle's exit. Consequently. enhanced became uniformly distributed along flame. contrary reference unforced flame where intense started only a distance from limited region vortical structures developed. optimal combination parameters are presented discussed.