滑动弧等离子体激励对旋流燃烧室节油熄火特性的影响

Influence of Gliding Arc Plasma on Flameout Characteristics in Swirl Combustor under Condition of Fast Fuel Reduction

针对航空发动机燃烧室在快速节油条件下扩稳防熄的迫切需求,为验证等离子体助燃(PAC)技术在拓宽动态熄火边界等方面的显著优势,建立了快速节油单头部旋流燃烧实验平台,并开展了滑动弧等离子体基于快速节油条件下的熄火特性研究。实验通过采集快速节油燃烧过程中OH*化学自发光信号,分析燃烧室熄火演化过程,对比研究了不同节油速率和流量下滑动弧等离子体激励对熄火特性的影响。研究表明,在动态节油下熄火边界明显小于准稳态条件下的熄火边界,随动态节油和进气流量的增大,熄火边界变窄;施加PAC后,助燃效果显著,节油条件下的贫油熄火油气比明显降低,尤其在较大节油速率和流量下仍能维持稳定燃烧。进气流量为15 m^(3)/h、节油速率为0.09/s时边界拓宽最大,由0.064拓宽到0.052,拓宽程度达到23%。

Aimed at the problems that aero-engine combustors need urgently to widen stability and prevent flameout under conditions of fast fuel reduction to verify the effect of plasma-assisted combustion(PAC)technology in widening the dynamic limit and other aspects,a swirl experimental platform is established with single dome under conditions of fast fuel reduction,and the dynamic characteristics study is conducted based on gliding arc plasma.Through collecting OH*chemical luminescence signals in the combustion process of fast fuel reduction,the combustion chamber flameout evolution process is analyzed,and then the influence of gliding arc plasma excitation on flameout characteristics is studied at different fuel reduction rates and flows in comparison.The results show that the lean blowout limit under dynamic fuel reduction is significantly smaller than that under quasi-steady conditions,and the lean blowout limit becomes narrower with the increase of dynamic fuel reduction and inlet airflow.After the application of PAC,the assisted combustion effect is significant,and the lean blowout fuel-air ratio of the fast fuel reduction condition is significantly reduced,especially under larger fuel reduction rate and inlet airflow can still maintain stable combustion.The limit widening is the largest at inlet airflow of 15 m^(3)/h and fuel reduction rate of 0.09/s,widening from 0.064 to 0.052,and the widening degree reaches 23%.