射流撞击雾化索太尔平均直径的计算

CALCULATION OF THE SAUTER MEAN DIAMETER OF JET-IMPINGING ATOMIZERS

关键词:  推进剂雾化  液滴  粒度分布  液体推进剂火箭发动机

Key words:  Propellant spray  Drop (liquid)  Particle size distribution  Liquid propellent rocket engine

摘要:

针对射流撞击雾化初始形成液膜的特征，推导出极坐标下自变量为极角的液滴尺寸分布函数的解析式，这种形式的分布函数与经典的Ｒ～Ｒ分布、上限对数正态分布等概率分布函数不同，可以计算任意撞击角下两股相同射流撞击或一股射流撞击壁面边缘在任意极角区域雾化所产生液滴的索太尔平均直径。计算结果表明，索太尔平均直径随撞击角增加而单调减小；射流直径、射流速度、射流温度变化时，索太尔平均直径也呈一定单调规律变化。本文还结合新一代液体火箭发动机层板式喷注器喷注单元雾化的特征进行了有关雾化机理的探讨。

Abstract:

According to the characteristics of the liquid film formed initially from jet-impinging atomization, a analytic formula of droplet size distribution function was deduced in a polar coordinate with polar angle as argument. Different from the typical Rosin-Ramller distribution and upperlog normal distribution, this kind of distribution function can be used to calculated the Sauter Mean Diameter of droplets in any polar angle regions produced by two impinging jets or splash atomization at any impinging angle. The calculation results show that the Sauter Mean Diameter decreases monotonically with the increasing of the impinging angle. The calculated curves of the Sauter Mean Diameter are given when one of the three factors, jet diameter, jet velocity and jet temperature, changes. Atomization mechanism of the injector element of a new generation of liquid rocket engine platelet injectors was also analyzed.