压力雾化近场液核破碎过程研究

Investigation on the Process of Liquid Core Breakup in Near-nozzle Region of Pressure Atomization

为探究近场液核的破碎过程,设计搭建了低喷射压力的喷雾可视化实验平台。采用高速摄像机以及高强度连续光源,对近喷嘴区射流液核的微观结构进行记录,结合图像后处理技术对射流液核结构进行量化以及统计分析。喷射压力为1MPa、2MPa、5MPa,环境条件为常温常压。实验观察到,在低喷射压力条件下,完整液核的长度随着时间的发展呈现周期性变化;液核主体上可以观察到规则的"圈层"液滴簇分布的结构;自远离孔口的过程中,"圈层"液滴簇沿径向逐渐向外扩张,同时相邻"圈层"液滴簇之间的距离越来越远。结合实验现象,对近场液核破碎过程进行了讨论。

To explore the near-field liquid core breaking process,a low-pressure spray visualization platform was designed and constructed.A high-speed camera and a high-intensity continuous light source were used to record the microstructure of the jet core near the nozzle,and the jet core structure was quantified and statistically analyzed in combination with image post-processing technology.The injection pressure was 1 MPa,2 MPa,5 MPa,and the environmental conditions were normal temperature and pressure.Experiments have observed that under low injection pressure,the length of the complete liquid core changes periodically with time.The regular "circle layer" cluster distribution structure can be observed on the main body of the liquid core.In the process of moving away from the orifice,the "circle layer" clusters gradually expand radially outward,and the distance between the adjacent " circle layer" clusters becomes farther.Combining with experimental phenomena,the process of near-field liquid core breakup was discussed.