TY - JOUR
T1 - Macroscopic and microscopic characteristics of a single-hole spray under low ambient pressure induced conditions
AU - Luo, Hongliang
AU - Zhang, Gengxin
AU - Dong, Panpan
AU - Nishida, Keiya
PY - 2022/6/28
Y1 - 2022/6/28
N2 - Flash boiling spray is a promising method to improve atomization, which subsequently affects the combustion phenomenon in engines. Therefore, an investigation on both macroscopic and microscopic characteristics of the flash boiling spray should be done to understand this behavior and mechanism. A mini-sac injector with a single hole was used under different injection pressures among 10, 15, and 20 MPa. Experiments were performed in a constant volume chamber with low ambient pressures varying from 5 to 100 kPa. First, macroscopic behaviors including morphology, spray tip penetration, spray angle, and spray cone angle were compared by a Mie scattering method. Then, microscopic characteristics of flash boiling spray were obtained with the help of particle image analysis technology. In order to analyze the droplet behaviors along the spray axis completely, a spray "slicer" was introduced to filter the spray. The influences of measurement location, injection pressure, and ambient pressure were discussed in detail. Results showed that although the injection pressure and measurement location have influences on the spray and atomization in both macroscopic and microscopic cases, the ambient pressure plays a more critical effect on it, indicating the low ambient pressure-induced flash boiling spray could improve the atomization much more efficiently.
AB - Flash boiling spray is a promising method to improve atomization, which subsequently affects the combustion phenomenon in engines. Therefore, an investigation on both macroscopic and microscopic characteristics of the flash boiling spray should be done to understand this behavior and mechanism. A mini-sac injector with a single hole was used under different injection pressures among 10, 15, and 20 MPa. Experiments were performed in a constant volume chamber with low ambient pressures varying from 5 to 100 kPa. First, macroscopic behaviors including morphology, spray tip penetration, spray angle, and spray cone angle were compared by a Mie scattering method. Then, microscopic characteristics of flash boiling spray were obtained with the help of particle image analysis technology. In order to analyze the droplet behaviors along the spray axis completely, a spray "slicer" was introduced to filter the spray. The influences of measurement location, injection pressure, and ambient pressure were discussed in detail. Results showed that although the injection pressure and measurement location have influences on the spray and atomization in both macroscopic and microscopic cases, the ambient pressure plays a more critical effect on it, indicating the low ambient pressure-induced flash boiling spray could improve the atomization much more efficiently.
KW - macroscopic behaviors
KW - microscopic characteristics
KW - flash boiling
KW - low ambient pressure
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85138998448&partnerID=MN8TOARS
U2 - 10.1615/AtomizSpr.2022042343
DO - 10.1615/AtomizSpr.2022042343
M3 - Article
SN - 1044-5110
VL - 32
SP - 15
EP - 33
JO - Atomization and Sprays
JF - Atomization and Sprays
IS - 8
ER -