Experimental study on the spray characteristics of an internal-mixing gas-liquid injector

• Published in: Acta astronautica Vol. 221; pp. 46 - 65
• Main Authors: Qiao, Wentong, Wang, Shaoyan, Yang, Xiaocong, Wan, Hegu, Deng, Zhi, Yang, Lijun, Fu, Qingfei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024
• Subjects: Gas-liquid injector; Impingement position of jets; Internal-mixing; Operating condition; Spray characteristics; Internal-mixing; Impingement position of jets; Gas-liquid injector; Operating condition; Spray characteristics
• ISSN: 0094-5765; 1879-2030
• DOI: 10.1016/j.actaastro.2024.05.006

To determine the spray characteristics of internal-mixing gas-liquid injector under various operating conditions, the experimental facilities for spraying are established. By means of high-speed camera, laser particle size analyzer and PIVlab, the effects of gas and liquid flow conditions on the spray characteristics, such as position of jet impingement, spray angle, breakup length, velocity distribution and droplet size, have been investigated in detail. Experimental results demonstrated that there are two types of atomization for this injector, namely impact atomization and aerodynamic atomization. The impingement position of the liquid jets is outside of the injector exit. Alternatively, no impingement occurs between the jets. The spray angle increases with the increase of liquid flow rate, and decreases with the increase of gas flow rate. The breakup length decreases with the increase of the liquid or gas flow rate. The higher the liquid flow rate, the greater the velocity distributed along the axial and radial direction. However, the effect of gas flow rate on the velocity along the axial and radial directions acts differently at different spatial position. An increase in the liquid flow rate causes the droplet diameter to increase first and then decrease. The droplet size will decrease when the gas-liquid momentum ratio increases. •Two types of atomization process: “aerodynamics fragmentation” and “impact fragmentation”.•Effects of gas/liquid flow rates on the position of jet impingement, spray angle, breakup length, velocity distribution and droplet size.•Effects of operating conditions on the two atomization mechanisms: “aerodynamics fragmentation” and “impact fragmentation”.•The dominant factor (mutual impact between the liquid jets or gas-liquid interaction) in atomization process depends on the gas flow rate.