摘要
基于Fluent软件模拟了柱型、扇型、锥型和混合型喷嘴真空喷射射流雾化过程,研究了喷嘴结构对动压力转换、射流速度和喷嘴出口湍动能的影响。结果表明,锥型喷嘴动压力较大,可提高静压能转换效率;扇型和锥型喷嘴喷射束宽度较大,利于大面积喷射成膜;扇型喷嘴易形成空化,出口湍动能较大,有助于液滴初次雾化破碎,而混合型喷嘴的空化层厚度最小,湍流区域最大。通过分析雾化锥角与喷嘴流量系数,发现扇形和锥直形喷嘴具有较大雾化锥角,但流量系数较小喷嘴压力损失较大;喷嘴直线段会提高锥型喷嘴雾化锥角和喷嘴出口湍动能,并使扇型喷嘴的流量系数增大,但射流雾化锥角减小。最后,本文尝试构建了真空喷射射流雾化数学模型。
The jet flow atomization in vacuum spray was modeled,approximated, and simulated with software packages Gambit and Fluent. The influence of the nozzle structure on the vacuum spray conditions, including the dynamic pressure conversion, jet-spray velocity, and turbulent kinetic energy at the nozzle outlet were evaluated. The simulated results show that the conical nozzle has a high conversion efficiency of dynamic pressure. The fan-shaped and conical nozzle is favorable for large-area film deposition, owing to their large spray beam width. The cavitation, associated with the fan-shaped nozzle and a large turbulent kinetic energy, promotes the primary breakup atomization of the droplets. We found that the fan-shaped and straight conical nozzles have a larger spray angle and smaller discharge coefficient. The strengths and weaknesses of the cylindrical and hybrid-shaped nozzles were also tentatively discussed.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2014年第2期101-105,共5页
Chinese Journal of Vacuum Science and Technology
基金
中央高校基本科研业务费专项资金资助项目(N110403001)
关键词
真空喷射沉积法
喷嘴
喷雾锥角
流量系数
高分子薄膜
Vacuum spray deposition, Nozzle, Spray angle, Discharge coefficient, Polymer thin film
