冲压发动机羽流温度 TDLAS 在线测量系统

为实现碳氢燃料冲压发动机羽流温度在线测量,以H_2O分子为目标组分,通过分子光谱仿真计算优选(7 444.352+7 444.371) cm~(-1)-(7 185.586 5+7 185.597 3) cm~(-1)谱线对,采用扫描波长直接吸收光谱-时分复用(SDAS-TDM)策略设计了用于碳氢燃料冲压发动机羽流参数测量的可调谐半导体激光器吸收光谱(TDLAS)系统,并利用预混平面火焰炉验证了该系统测温精度,结果显示采用此系统对预混平面火焰炉高度1 cm处火焰温度测量结果与标准参考值相对偏差均在15%之内。在此基础上,将该系统应用于碳氢燃料冲压发动机羽流参数测量,通过交替调制1 392 nm与1 343 nm半导体激光器,测量调制激光经待测区域后的光强衰减信号,获得H_2O分子在(7 444.352+7 444.371) cm~(-1)和(7 185.597+7 185.597 3) cm~(-1)谱线吸收光谱,通过双线技术实现了发动机羽流温度在线测量,为碳氢燃料冲压发动机燃烧组织与性能评估提供重要参考。

TDLAS online measurement system for plume temperature of ramjet engine

In order to realize the online measurement of hydrocarbon fuel ramjet engine plume temperature, the spectral line pair of (7 444. 352+7 444. 371) cm -1 ~ (7 185. 586 5+7 185. 597 3) cm -1 was optimally selected through molecular spectral simulation taking H2O molecular as the target composition, and tunable diode laser absorption spectroscopy (TDLAS) system was designed to measure the parameters of hydrocarbon fuel ramjet engine plume using scanned-wavelength direct absorption spectroscopy-time division multiplexing (SDAS-TDM) strategy. Moreover, the temperature measurement accuracy of this system was verified by premixed flat-flamed burner. The results show that the relative deviations between the measured flame temperature at the height of 1cm of the premixed flat-flamed burner using this system and the standard reference value are all within 15% . On this basis, the system was applied to measure the parameters of the hydrocarbon fuel ramjet engine plume. Through alternately modulating of 1 392 nm and 1 343 nm diode lasers, the intensity attenuation signal of the modulated laser passing through the measuring zone was measured, the H2O molecule absorption spectrums at (7 444. 352 + 7 444. 371) cm -1 and ( 7 185. 586 5 + 7 185. 597 3) cm -1 lines were obtained. The online temperature measurement of the hydrocarbon fuel ramjet engine plume was realized with two-line technique, which provides important references for the combustion organization and performance evaluation of hydrocarbon fuel ramjet engine.