壁面喷射当量比对支板凹腔耦合燃烧的影响

在纯净空气来流条件下,对于全高后掠支板与凹腔耦合的燃烧室,采用分级喷射供油,对比研究了壁面喷射当量比对壁面压力和燃烧性能的影响。结果表明:在支板喷射当量比一定的情况下,随着壁面喷射当量比增加,壁面静压峰值升高,静压开始提升的位置向上游移动,总当量比达到1.1时发生溢流;一维分析表明,马赫数在支板附近降到1以下,在凹腔处达到0.5左右,在出口扩张段恢复至1以上,燃烧室处于亚燃模态;燃烧性能方面,保持支板喷射当量比一定,随着壁面喷射当量比的增加,总压恢复系数提高,出口总温增加,燃烧效率降低。

Effect of equivalence ratio of wall injection on strut-cavity coupled combustion

For the combustor based on full-height swept strut coupled with cavity,the experiments were conducted under clean air conditions and the inlet air was preheated by storage heater.Liquid kerosene was used as fuel and was injected by stages from the wall and strut.The effect of equivalence ratio of wall injection on the static pressure distribution and combustion performance was studied by experiments and one-dimensional analysis.The results show that as the equivalence ratio of strut was constant,with the increasing of wall injection equivalence ratio,the peak static pressure increased,and the position of the lifting of pressure was moved upward.When the total equivalence ratio reached 1.1,an inlet unstart occurred.One-dimensional analysis shows that the Mach number decreased below 1 in the strut area,then reached 0.5 in cavity and finally back to more than 1 in diverging area of outlet.The combustor worked in subsonic mode.In the combustion performance aspect,increasing of wall injection equivalence ratio ledes to increase of total pressure recovery coefficient,increase of total temperature at exit,but reduction of combustion efficiency.