基于500Hz OH-PLIF技术的超声速燃烧室火焰结构

500Hz high-speed OH-PLIF technology was used for the research of the flame structure in supersonic combustion chamber, which was characterized by short time-lag and high turbulence in cavity chamber. Combining the pressure of the wall surface, the ignition, stabilization and extinguishing of the flame were studied. The results showed that ignition occurred when the hydrogen equivalents were 0.1 and 0.3. PLIF camera got the image in 2ms under the spark. A detonation combustion existed in the cavity of the equivalent ratio of 0.1, and the flame was slower to reach stable state in the cavity (about 65ms). In the process of stabilization of the flame, the equivalent 0.3 was in an incomplete combustion state, the burning area was closer to the wall, the burning position and nuclear position of the fire were greatly changed at the equivalent 0.3. At the equivalent of 0.1, the flame was transmitted from the middle of the cavity to the front edge of the cavity with a process of a briefly increased flame. Flame extinguished at the front edge of the cavity. However the equivalent 0.3 was slightly weaker, which was eventually extinguished between the front edge of the cavity and the position of hydrogen injection.