Investigation of Flashing LN2-Jets in Terms of Spray Morphology, Droplet Size and Velocity Distributions

Kurzfassung

For a detailed experimental investigation of superheated cryogenic fluids the new cryogenic test bench M3.3 with a temperature controlled injection system was built at the DLR Institute of Space Propulsion in Lampoldshausen. In a first test campaign flash boiling liquid nitrogen sprays were visualized by means of high-speed shadowgraphy to determine the resulting spray patterns and spray angles. The cryogenic spray patterns are compared with break-up correlations for storable fluids from literature. The dependence of droplet velocities and diameters on the injection conditions was investigated at a constant position in the spray by means of Phase Doppler Anemometry.