RT Journal Article ID 53f188142210660d A1 Yuan, Tony A1 Tang, Marx T1 THE EFFECTS OF GAS LAYER AND LIQUID PHYSICAL PROPERTIES ON THE BREAKUP OF COAXIAL LIQUID JET SPRAY JF Atomization and Sprays JO AAS YR 2016 FD 2016-02-10 VO 26 IS 6 SP 585 OP 605 K1 coaxial injector K1 gas layer thickness K1 surface tension K1 viscosity K1 spiral-type turning K1 ligament AB A coaxial injector is mainly used in large-scale liquid rocket engines. By utilizing optical methods, this research studies the effects of the gas to liquid velocity ratio (2.9−60), gas layer thickness (1.2−2.4 mm), and liquid physical properties (surface tension and viscosity) on the breakup and atomization of coaxial liquid jet spray. The spray angles, droplet size distributions, and breakup processes at different experimental conditions are observed and analyzed. The results reveal the significance of the breakup of the coaxial jet spray as the surrounding high-speed air confines the spray spatially and forces the inherent unstable liquid column into spiral-type turning, then elongates into a ligament before instantaneous breakup. Once the liquid jet has broken up, the outer high-speed air appears to have no further effect on the spray. Owing to this controlling breakup process, the spray angle appears to be increased with increasing velocity ratio and decreased with increasing gas layer thickness, and the droplet size distribution of coaxial jet spray appears to be uniform, concentrated, and invariant after the jet has broken up. Liquid viscosity shows a strong effect on coaxial jet spray. With higher viscosity, the liquid ligament is stretched wider before disintegration; that is, the liquid ligament may utilize more energy of the surrounding high-speed air for liquid atomization, thus producing a larger spray angle and smaller droplet sizes, as observed in the experiments. PB Begell House LK https://www.dl.begellhouse.com/journals/6a7c7e10642258cc,4d9fdd662f4154ab,53f188142210660d.html