High-Speed Measurements of Dynamic Flame Stabilization Processes in High-Pressure Combustion Systems

The Phase-II research is a natural extension and a significant advancement over the Phase-I research, which has successfully demonstrated high-speed, burst-mode, polarization-based, dual-plane, stereoscopic PIV measurements synchronized with OH-PLIF imaging of turbulent swirling combustion in a generic gas-turbine combustor with and without acoustic forcing. We propose to conduct high-speed, burst-mode, two-color, dual-plane stereo-PIV (DP-stereo-PIV) measurements synchronized with dual-plane OH-PLIF imaging, two-color OH-PLIF thermometry and CH2O/OH-PLIF imaging of natural-gas-fueled turbulent swirling combustion to completely and unambiguously determine the nine-component strain-rate tensor, the flame stretch rate, the flame curvature and the flame orientation and generate unprecedented benchmark databases on turbulent swirling combustion with and without combustion instabilities at elevated pressure. Then, we propose to perform a systematic and indepth investigation of turbulent, swirling spray combustion by conducting high-speed, burst-mode DP-stereo-PIV measurements, OH/fuel-PLIF imaging, tomographic imaging of droplets and OH* chemiluminescence and two-color OH-PLIF imaging synchronized with fuel-PLIF imaging. The proposed research aims to substantially advance state-of-the-art understanding of turbulent spray combustion in aircraft engines, including combustion instabilities, flame stabilization and blowoff, and guide design and operation of high-performance combustion/propulsion systems with improved operability, reliability and sustainability.