等离子体增强含硼燃气二次燃烧实验分析

Experimental analysis on plasma assisted secondary combustion of boron-based gas

为研究等离子体助燃条件下含硼燃气在补燃室的二次燃烧特性,建立了排除来流空气掺混效应的扩散燃烧实验模型。利用高速摄影仪拍摄了含硼燃气在补燃室的火焰照片,得到了有无等离子体条件下的燃烧火焰形貌;测量了补燃室不同截面的静压和总压,分析了有无等离子体条件下含硼推进剂在固冲发动机中的燃烧效率。实验结果表明:在含硼燃气二次燃烧过程中加入等离子体炬,等离子体炬后方区域火焰更加明亮,硼燃烧更加充分;断开等离子体炬后,补燃室静压和总压出现压力突降台阶,说明加入等离子体后可以加快化学反应速率,提高含硼燃气在固冲发动机中的燃烧效率,从而提高了补燃室的压强;且放电功率越高,含硼燃气在固冲发动机中燃烧效率的增长率越高。

In order to research the influence of plasma on the secondary combustion characteristic of boron-based gas in the afterburning chamber,a diffusion combustion experimental model which can exclude the mixing effect of intake air on the boron-based gas is designed and built.The flame image of boron-based gas secondary combustion is measured by the highspeed photographic apparatus to analyze the degree of brightness of the flame and the flame shape;the total pressure and static pressure of different cross-sections in the combustion chamber are measured to analyze the combustion efficiency of boron-based propellant under the influence of plasma.The results show that when adding plasma torch at the secondary combustion of boron-based gas,the combustion efficiency of boron-based gas increases and the boron-based flame is brighter;the abrupt decrease in the total pressure and static pressure appears when turning the plasma torch off.These show that the chemical reaction rate of boron-based gas increases with plasma,and the combustion efficiency of boron-based propellant in the solid rocket ramjet increases with plasma,which leads to the increase of the total pressure and static pressure with plasma;the combustion efficiency increases with the growth of discharge plasma power.