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针对甲烷/空气预混多喷嘴火焰的自激振荡燃烧进行了激光可视化实验研究.采用动态压力传感器记录压力脉动,利用激光诱导荧光技术对多喷嘴火焰结构进行相同步测量.实验结果表明,多喷嘴燃烧室的压力脉动频率为41 Hz,幅值为1370 Pa.火焰沿着轴向发生周期性跳动,在0°～60°相位时,喷嘴发生回火.中心火焰的推举高度比外侧火焰高,但燃烧反应强度低于外侧火焰.在相邻火焰干涉区发生局部熄火与重新点燃,相邻火焰干涉区和火焰根部区的不稳定热释放和压力脉动的耦合是引起预混多喷嘴火焰自激振荡燃烧的主要原因.“,”Experimental study on combustion oscillation in a premixed methane/air multi-nozzle flame is conducted with laser diagnostic technology.Dynamic pressure is recorded using pressure transducers.Phased-locked planar laser-induced fluorescence (PLIF) is enployed to identify flame structure.Experimental results show that the frequency of pressure fluctuation in the combustor is 41 Hz with the corresponding amplitude being 1370 Pa.The multi-nozzle flame oscillates along the axial direction periodically.The flame flashes back into the burner during phase 0° to phase 60°.The liftoff height of center flame is larger than that for outer flame,however,the combustion intensity is lower.The multi-nozzle flame is local extinguished and re-ignited alternately in the interacting region.The coupling of unsteady heat release with the pressure oscillation in the interacting region and flame base region is the main reason for inducing self-excited combustion oscillation of the premixed multi-nozzle flame.