抄録
The objective of this study is to explore the effects of incident shock waves on combustion downstream of a cavity flameholder. The images of flame chemiluminescence showed that the flame looks extinguished downstream of an incident shock wave, as well as OH-PLIF measurements indicated higher OH concentration upstream of the incident shock wave, while lower OH concentration downstream of the incident shock wave. The results of two-dimensional numerical simulations for reacting flows showed that the incident shock wave generates a strong recirculation zone and reverse flows, and the main flow curved around the zone, corresponding well to the flame structure seen by experiments. In addition, it was found that about 90% of the injected H2 was converted to H2O at the rear edge of the calculated wall domain when an incident shock wave was introduced, which means that cavity-stabilized flames is not extinguished by the incident shock wave but burnt out there, thus the fuel was almost fully consumed. That is to say, the incident shock wave enhances chemical reactions because the generated recirculation zone and low speed region increases residence time and increased turbulent kinetic energy enhances the mixing.
