희박 예혼합 메조스케일 다중노즐 수소 화염의 곡률 분포

Abstract

Local structures of lean fully-premixed hydrogen-air flames in a mesoscale multinozzle array were studied in a tunable combustion test facility, using instantaneous OH PLIF measurements and subsequent image processing techniques. We observe that under thermoacoustically stable conditions, pure hydrogen flame ensemble takes on a conical structure and they are stabilized in isolation without strong flame-to-flame interactions. Under unstable conditions, however, marked flame front deformation and cusp formation occur due to high amplitude velocity fluctuations. Our curvature calculation results reveal that the probability density function distribution is characterized by a positive average value, meaning that the formation of convex contours is more pronounced in lean-premixed pure hydrogen combustion environment.