甲烷/空气预混旋流火焰回火实验与模拟研究

Flame flashback is one of the important combustion instability problems in lean premixed low-pollution combustor. In this paper, the flashback of methane/air premixed swirl flame in a bluff-body swirl burner is investigated with experiments and large eddy simulation. The results show that for low-turbulence (Reynolds number Re = 4000) and high-swirl conditions (swirl number S = 1.3), the upstream flame propagation is dominated by the flame tongue leading flashback mode. The swirling flame propagates upstream around the central bluff-body wall at almost constant flashback speed, during which the flame-flow interaction mainly occurs in the leading side of the flame tongue. In the flame reference frame, the flow deflection upstream of the flame tongue is mainly affected by the radial pressure gradient, Coriolis force and centrifugal force.