Back to Search
Start Over
Droplet velocity and diameter distributions in flash boiling liquid nitrogen jets by means of phase Doppler diagnostics
- Source :
- Experiments in fluids 61(8), 182 (2020). doi:10.1007/s00348-020-03020-7
- Publication Year :
- 2023
- Publisher :
- Universität Stuttgart, 2023.
-
Abstract
- Due to current and future environmental and safety issues in space propulsion, typical propellants for upper stage or satellite rocket engines such as the toxic hydrazine are going to be replaced by green propellants like the combination of liquid oxygen and hydrogen or methane. The injection of that kind of cryogenic fluids into the vacuum atmosphere of space leads to a superheated state, which results in a sudden and eruptive atomization due to flash boiling. 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 DLR Lampoldshausen. After a first test campaign with high-speed shadowgraphy of flash boiling liquid nitrogen sprays, a laser-based Phase Doppler system was set-up to determine the spatial distributions of droplet velocities and diameters in highly superheated sprays. The spatial distributions revealed a core region with high mean velocities close to the injector orifice. With increasing distance from the injector orifice, the sprays develop a more and more monodisperse pattern. These distributions also showed that atomization due to flash boiling generates finer sprays with growing degrees of superheat. In certain spray regions, two droplet populations varying in their direction of motion, velocity and diameter due to possible recirculation zones were observed. The experimental data of flash boiling liquid nitrogen generated within this study provide a comprehensive data base for the validation of numerical models and further numerical investigations.<br />Deutsche Forschungsgemeinschaft<br />Projekt DEAL
- Subjects :
- Materials science
business.product_category
Computational Mechanics
General Physics and Astronomy
Shadowgraphy
01 natural sciences
010305 fluids & plasmas
law.invention
010309 optics
law
0103 physical sciences
atomization
ddc:530
cryogenic
sprays
flash boiling
Fluid Flow and Transfer Processes
Propellant
Flash boiling, cryogenic, atomization, spray, Phase Doppler
Injector
Mechanics
Liquid nitrogen
Superheating
Raketenantriebe
spray
Rocket
Mechanics of Materials
Phase Doppler
Liquid oxygen
business
Body orifice
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Experiments in fluids 61(8), 182 (2020). doi:10.1007/s00348-020-03020-7
- Accession number :
- edsair.doi.dedup.....c9263250bc82153ce377c0b0f89a0049
- Full Text :
- https://doi.org/10.18419/opus-13138