The Influence Of Cavity Configuration On Supersonic Flow And Combustion Process

With the development of scramjet technology, cavity flame holder has been paid greatattention by researchers domestic and overseas. Under this circumstance, numerical simulationmethod was used in this paper to explore the rules of cavity influence on supersonic flow andcombustion process in scramjet combustors. Different cavity configurations and workingconditions was discussed here to illustrate these rules, in which serious choking phenomenonwas discovered in low total pressure conditions with solutions put forward and verified.With different types of cavity combustors studied in this paper, the rules show thatshock-cell structure, shear layer and vortex inside the cavity can promote the diffusion of fuel,temperature and combustion process. The cavity steps played a conclusive role in non-reactionconditions, but in reaction conditions, the back step would not have so much influence. Localvelocity of sound increased due to the increase of temperature, therefore the combustion processmostly take place in the transonic and subsonic velocity area.The shear layer would be thinner when the inlet pressure increased, and the hightemperature area, reaction space and time would also be limited. At this time, different cavityconfigurations can show their different advantages.Change the jet angle of hydrogen or join a divergence angle can eliminate choking influence,of which, change jet angle would make combustion efficiency decreased, in contrast, joindivergence angle effects was better.