喷嘴雾化特性的试验及数值模拟

Experimental Study and Numerical Simulation on Spray Characteristics of Different Nozzles

采用试验方法研究了单相喷嘴、两相喷嘴的喷雾特性随液体压力、气液比、轴向距离和径向距离的变化规律.建立了喷嘴雾化模型,采用数值模拟方法研究了两相喷嘴的喷雾特性及气体入射角度、喷嘴水平间距对喷雾特性的影响.结果表明:单相喷嘴液滴平均直径随液体压力的增大而减小,随轴向距离和径向距离的增大而增大;两相喷嘴液滴平均直径随气液比的增大而减小,随轴向距离的增大呈现先减小后增大的趋势;改变气体入射角度,气体流场扩散角度一定,始终为23.5°;改变喷嘴水平间距,两个喷嘴各自的气体流场几乎没有相互影响,液滴平均直径沿轴向总体呈现先减小后增大的趋势.

The effects of following factors on the spray characteristics of single-and two-phase nozzles were experimentally studied,such as the liquid pressure,air-liquid ratio,axial distance and radial distance,etc.,while the influence of incidence angle of air flow and horizontal space between two nozzles on the spray characteristics of two-phase nozzles was numerically simulated using the nozzle spray model newly set up.Results show that the droplet mean diameter of single-phase nozzles reduces with the rise of liquid pressure,which increases with the rise of both axial and radial distance.The droplet mean diameter of two-phase nozzles reduces with the rise of air-liquid ratio,which reduces first and increases later on with the rise of axial distance.The dispersion angle of air flow field is always kept at 23.5°,not affected by the incidence angle of air flow.The space between two nozzles has little influence on gas flow field of both the nozzles,and the droplet mean diameter reduces first and increases later on along the axial direction.