The effects of turbulence on the lean blowout mechanisms of bluff-body flames

The lean blowout mechanisms of premixed bluff-body flames are experimentally investigated at various turbulence intensities. Turbulence levels varied using a novel generator, which combines static grid and fluidic jet impingement techniques. Three different probed to study their effects on blowout. three conditions span across the combustion regime diagram, from flamelets broken reactions. For all levels, process is induced through controlled fuel flow rate reduction. transient captured simultaneous high-speed diagnostic systems: particle image velocimetry (PIV), stereoscopic PIV (SPIV), C2*/CH* species measurements. two systems used resolve instantaneous velocity vorticity fields, diagnostics allow for global equivalence ratios be evaluated throughout duration results show that dynamics vary with intensity. At low flame experiences effect where boundary interacts shear layer vorticity. This imparts high strain rates along length flame, leading As increase, mechanism becomes less dependent interactions more driven by flame–turbulence interactions. conditions, flame-eddy within freestream augment stretching via increased straining small-scale corrugations. Increased disrupts stabilization process, ultimately in