利用TDLAS技术开展吸气式发动机来流热试实验参数测量

TDLAS-Based Measurements of Parameters for Incoming Flow Hot-Firing Test of Air-Breathing Rocket Engine

利用可调谐半导体激光器吸收光谱(TDLAS)燃烧诊断技术,开展了吸气式发动机来流热试实验燃气温度、H2O组分浓度和气流速度测量。选用1392 nm和1395 nm分布反馈式(DFB)半导体激光器,构建了交叉光束时分复用(TDM)系统,通过扫描波长方法,交替调制两个激光器以获得燃气双吸收谱线中心(7185.597 cm-1和7168.437 cm-1)附近吸收光谱。根据双线测温原理,通过双线积分吸收率比值推断燃气静温,并由此温度测量值,结合单线积分吸收率计算燃气中H2O组分浓度,此外,根据成70°夹角双激光束吸收中心的多普勒频移量计算气流速度,从而实现了发动机燃气参数的非接触式和实时在线测量。

Tunable diode laser absorption spectroscopy （TDLAS）-based sensor is applied to measurement of pathintegrated static temperature, H2O concentration and local velocity for incoming flow hot-firing test of air-breathing rocket engine. The measurements are achieved using time division multiplexing （TDM） system with scanned- wavelength method, which contains 1392 nm and 1395 nm distribute feedback （DFB） diode lasers. The absorption spectra of gases near 7185. 597 cm-1 and 7168. 437 cm-1 are obtained by modulating the two lasers alternately. The value of temperature is deduced from the ratio of two-line measured absorbances, and the water vapor concentration is deduced from the measured absorbance of one transition and the measured temperature, moreover, gas velocity is deduced from the measured Doppler-shift absorption of the two beams, which make an angle of 70°. Therefore, the in-situ and non-intrusive measurements of parameters are applied for gas in rocket engine.