摘要
平孔喷嘴作为被广泛应用的雾化设备之一,其内部流型对雾化效果具有至关重要的影响。而目前对喷嘴内流型的判定方法还并不统一。本文建立了喷嘴内流型变化判定方法的数学模型,并利用模型喷嘴长度与直径比(L/d)、喷嘴入口倒角半径与直径比(r/d)和操作压力对流型的影响规律进行了模拟分析。结果表明:L/d对喷嘴内流型有一定的影响,L/d越大,越不易发生柱塞流;r/d对喷嘴内空穴区的强度影响显著,r/d越大,空化强度越低,越不易发生柱塞流,但喷嘴r/d大于0.05时,柱塞流依然可以发生;喷射压力对喷嘴内流型变化以及流量系数影响显著,流量系数与喷嘴内流型有一定的对应关系。应用本文的研究成果,可以通过合理地设计喷嘴结构和操作条件,使得喷嘴内流型始终处于空穴流区间,以达到强化雾化效果的目的。
The plain-orifice is the most common type of atomizer. The nozzle state has a tremendous effect on the external spray. At present, the judgement method of the flow pattern is not uniform. In this paper, mathematical model of the judgement of flow pattern was established, the law that the flow pattern was affected by L/d, r/d and operating pressure was analyzed by using the model. The results showed that the bigger L/d, the more difficult hydraulic flip occurred. The bigger r/d, the lower cavitation intensity, the more difficult hydraulic flip occurred, but hydraulic flip still occurred when r/d 〉0.05. Injection pressure had a significant influence on the flow pattern and the coefficient of discharge of the nozzle, there was a certain relationship between the flow pattern and the coefficient of discharge. According to the results of this paper, we could keep the flow pattern of the nozzle be cavitating by designing nozzle structure and operating conditions reasonably to enhance atomization.
出处
《计算机与应用化学》
CAS
2016年第10期1074-1079,共6页
Computers and Applied Chemistry
关键词
平孔喷嘴
空穴
喷射压力
柱塞流
the plain-orifice nozzle
cavitation
injection pressure
hydraulic flip
