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ID 96

Effect of liquid properties on spray characteristics of gas-centered swirl coaxial injectors under various ambient pressure

Tianyu Li
Shanghai Jiao Tong University
China

Shiyan Li
Shanghai Jiao Tong University
China

Xunchen Liu
Shanghai Jiao Tong University
China

Yuyang Li
Shanghai Jiao Tong University
China

Fei Qi
Shanghai Jiao Tong University
China

Yi Gao
Shanghai Jiao Tong University
China

 

Abstract:

As a kind of practical injectors widely used in liquid oxygen-kerosene rocket engines, gas-centered swirl co-axial (GCSC) injectors have attracted more and more attention over recent decades. Most of previous experi-ments are dedicated to the effect of geometric parameters and momentum flux ratio on the spray patterns un-der various pressures and room temperature. However, the effect of liquid temperature has not been investigat-ed previously. In this work, spray characteristics, such as intact length and spray cone angle, under various am-bient pressures, liquid temperatures and gas flow rates, are analyzed based on back-illuminated high-speed im-aging technique. Three sheet breakup regimes, namely perforated breakup, wave-assisted breakup and early breakup, are identified under different conditions. The intact length decreases under the order of perforated breakup, wave-assisted breakup and early breakup, while the spray cone angle reaches its minimum under the wave-assisted breakup regime. A retarded transition from perforated breakup to wave-assisted breakup and then to early breakup with increasing central gas flow rate is revealed at elevated liquid temperature and ambi-ent pressure. These results provide insightful information for understanding the breakup mechanism and up-grading the design criteria of GCSC injectors.