Effect of External Thermo-Convective Perturbation on Cool Flame Dynamics: A Multidimensional Multi-Physics CFD Analysis

The objective of this ground investigation was to use flight data obtained from PSI through NASA’s Flame Extinguishment Experiment (FLEX) to quantify how externally imposed thermal and convective perturbations regulated the dynamics and ultimate fate of already established droplet cool flames, and to explain run-to-run variability by isolating the roles of deliberate heating and unintentional drift-induced convection. Focusing on both small and large droplets, the work mapped stability windows for ignition, sustained oscillation, transitions to hot ignition and warm-flame behavior, and extinction under microgravity. By leveraging and extending the FLEX data in the PSI, this study produced reusable models and sensitivity analyses that coupled low-temperature chemistry with transport and radiative effects.