Measurement of airblast atomization of low temperature kerosene with 25  kHz digital holography

Atomization of low temperature fuel is of great importance in a jet engine combustor, and its visualization and diagnostics are challenging, especially in the presence of shreds and ligaments. A 25 kHz picosecond pulsed digital inline holography system is applied to measure the spray produced by an airblast atomizer with low temperature kerosene. The breakup process of shreds and ligaments of -37^∘C kerosene are visualized and analyzed, revealing the transition of liquid jet disintegrating into droplets under the atomizing air film. Three-dimensional positions and size distributions of droplets in spray are acquired. It is found that a decrease in the kerosene temperature increases shreds and ligaments in the spray, which eventually leads to reduction of droplet density and increase of droplet size, while increasing the air pressure can compensate the degradation. This work also demonstrates that high speed holographic imaging is a powerful tool in spray diagnostics and liquid breakup visualization.