Burst-Mode-LaserBased Sensor Suite for High-Speed 2D Fuel-Air Ratio and Heat-Release Rate Measurement for Combustor/Augmentor Instability

The objectives of the proposed Phase-II research effort are to develop a stable and reliable burst-mode-laser (BML)based sensor suite for spatially and temporally resolved, 2D fuel/air ratio (FAR) and heat-release rate (HRR) measurements at a speed of 10-kHz or greater for combustors/augmentors instability study. The Phase-I research effort has been successful to show that the proposed BML sensor suite is capable of performing three state-of-the-art laser diagnostics techniqueslaser induced breakdown spectroscopy (LIBS), spontaneous Raman spectroscopy (SRS), and CH2O/OH planar laser-induced fluorescence (PLIF)for high-speed 2D FAR and HRR measurements within pressure range of 116 bars. During the Phase-II, the sensitivity and precision for FAR measurements with BML sensor suite will be further improved. A widely tunable OPO for performing BML-based 2D HRR measurements will be developed. The full packaged BML sensor suite for FAR and HRR along with multiple species concentration and temperature measurements will be employed for combustion instability study in the AFRL test rigs and burners.