等离子体对燃气在补燃室中燃烧特性的影响

为研究等离子体对多组分燃气在发动机补燃室中的助燃特性,建立了多组分燃气供给系统以及扩散燃烧实验模型。测量了等离子体炬的发射光谱,得到了等离子体炬的主要激发态粒子;拍摄了多组分燃气在补燃室的扩散火焰照片,得到了等离子体对多组分燃气的扩散火焰形貌的影响;测量了补燃室4个不同截面上的静压和总压,分析了等离子体对多组分燃气在发动机中燃烧效率的影响。实验结果表明:等离子体炬主要产生氮气和氧气的激发态粒子;加入等离子体后,喷出冲压尾喷管的火焰长度得到进一步缩短,说明等离子体可以在更短的燃烧室长度内使得多组分燃气得到更加充分的燃烧;加入等离子体时,补燃室不同截面的静压和总压都会出现突升台阶,说明等离子体可以加快燃气的化学反应速率,提高多组分燃气在发动机中的燃烧效率,且等离子体功率越高,燃气燃烧效率的增长率越高。

Effect of plasma on combustion characteristic of fuel gas in afterburning chamber

In order to study the influence of plasma on the combustion characteristic of multicomponent fuel gas in the ramjet chamber, a multicomponent fuel gas supply system and a diffusion combustion experimental model based on the ramjet, which can exclude the mixing effect of intake air on the fuel gas, are designed and built. The main active particles produced by discharge plasma torch are analyzed with emission spectrometry; the flame combustion photos of multicomponent fuel gas is taken to analyze the influence of plasma on the flame shape; the total pressure and static pressure on four different cross sections of the afterburning chamber are measured to analyze the combustion efficiency of fuel gas under the influence of plasma. The results show that the main excited particles of N₂ and O₂ are generated with excitation of plasma; under the active particles of plasma, and the flame length in the scramjet nozzle becomes shorter, which means that multicomponent fuel gas can burn more completely with plasma; the abrupt increase in the total pressure and static pressure appears when plasma is working, which shows that the combustion efficiency of multicomponent fuel gas in the ramjet increases with plasma too, and the combustion efficiency increases with the growth of discharge plasma power.