Oscillatory temperature measurements in a pulsed microgravity diffusion flame

Results from an experimental study of a pulsed, laminar, propane gas-jet di ffusion flame in microgravity are presented. The primary objective of the s tudy 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 fla me base, was used to provide axisymmetric, controlled, and repeatable distu rbances to interact with the flame, Measurements of the oscillatory tempera ture were used to elucidate the evolution of the imposed vortex as it conve cts downstream. Regions of the flame where energy transfer between the osci llations and the mean thermal field occur and the direction of the energy t ransfer were identified. Differences with normal gravity behavior were note d. Finally, correlations between the temperature and dame radiation oscilla tions were provided.