脉冲爆震发动机点火过程离子催化效应数值模拟

Numerical simulation for ion catalytic effect in ignition process of pulse detonation engine

利用气体电离理论推导出氢气-空气混合气体电离后组成成分,理论分析活性基团对燃烧速率及剧烈程度的催化效应,以及不同点火能量、活性基团浓度对缓燃转爆震（DDT）过程的影响.结合氢气-空气燃烧23步化学反应动力学机制,采用FLUENT软件对不同工况下的DDT过程进行模拟,与理论分析结果对比.结果表明：点火温度为2000～2500K时,活性基团的加入,可提高燃烧速率,DDT时间可缩短9.91％～21.08％,DDT距离可缩短3.32％～8.08％,DDT时间和DDT距离的改变幅度随点火温度的升高而增大.点火能量较高时应该考虑气体电离效应.

The gas composition was devived using the theory of gas ionization after hy- drogen-air mixed gas ionization. The catalysis effect of active group on combustion rate and intensity was found out with the theoretical analysis, and the influences on deflagration to detonation transition （DDT） process in different ignition energies and different concentra- tions of active group were analyzed. Fully considering the hydrogen-air combustion reaction 23-step kinetics mechanism, the the numerical simulation method was used to study DDT process in different cases by FLUENT, and the theoretical analysis was verified. Results show that when the ignition temperature is in the range of 2000--2500K, the reactive group in the process of ignition can increase the combustion rate; DDT time can be shortened by 9.91 %--21.08%, and DDT distance can be shortened by 3.32%-8.08%. With increase of the ignition temperature, DDT time and DDT distance increase. Gas ionization effect should be considered if ignition energy is high.