Temperature measurement of swirling flames using near-infrared emission spectroscopy of H2O

Internal temperature monitoring of high speed propulsion system is of great significance for engine performance evaluation and life prediction. As a passive optical measurement method without external light source and flow field interference, emission spectrum measurement technology has a good application prospect in harsh measurement environment. As the main combustion product, high temperature water vapor has a high emission intensity in the near infrared band, which is very suitable for temperature measurement applications. The frequency band integral ratio is proposed to eliminate the high resolution measurement requirement of spectrum acquisition system, and the temperature distribution of swirl flame is measured successfully.