Oscillatory temperature measurements in a pulsed microgravity diffusion flame

Results from an experimental study of a pulsed, laminar, propane gas-jet diffusion flame in microgravity are presented. The primary objective of the study was to investigate the interaction of the imposed vortex with the jet and flame flowfield under momentum-dominated conditions. A novel technique, which used a sinusoidally driven iris placed concentrically around the flame base, was used to provide axisymmetric, controlled, and repeatable disturbances to interact with the flame, Measurements of the oscillatory temperature were used to elucidate the evolution of the imposed vortex as it convects downstream. Regions of the flame where energy transfer between the oscillations and the mean thermal field occur and the direction of the energy transfer were identified. Differences with normal gravity behavior were noted. Finally, correlations between the temperature and dame radiation oscillations were provided.