横流中单喷嘴雾化形态与两相掺混特性研究

Study on Single-Nozzle Spray Pattern in Crossflow and Two-Phase Mixing Characteristics

搭建了冷态横流-喷雾掺混实验台,采用粒子图像速度仪测量了方腔通道内离心喷雾在横流中的雾化形态和气液两相相互作用下的掺混过程,获得了沿掺混流场不同横截面的液滴分布图像和流场结构特性.对不同喷嘴压力、不同雾化粒径在不同横流速度下的掺混过程和流场结构进行了系统的研究,分析了对称旋涡对结构形成的原因、结构特点及影响参数,得到了单喷嘴布置下横流-喷雾系统的掺混规律.结果表明,液气动量比是影响掺混的重要因素,选择合适的液气动量比能取得较好的掺混效果.实验结果为揭示水冲压发动机掺混室内的掺混过程提供了参考,也为工程中类似过程的掺混结构设计提供了依据,同时为进一步研究高温高压下实际发动机掺混室内部的掺混过程奠定了基础.

The spray pattern in the crossflow and the gas-liquid mixing process of centrifugal spray in a rectangular duct were measured with PIV technology on a crossflow-spray mixing rig established. The droplets distribution and the flowfield construction at the cross-sections along the mixing flowfield were obtained,and the mixing process and the flowfield construction under different nozzle pressure,spray droplet,and crossflow velocity were explored. The formation process,the structural characters and the impact parameters of the counter-rotating vortex pair （CVP） were analyzed,and the mixing rule of the crossflow-spray with the single nozzle arrangement was achieved. The results show that the liquid-gas momentum ratio is an important factor affecting the mixing process,and choosing appropriate liquid-gas momentum ratio may result in a better mixing effect. Our experimental results should be useful in understanding the mixing process in the mixing chamber of water ramjet and in the structural design of the similar mixing process in engineering.