撞击式射流速度特性及液滴粒度特性的试验

Experiment on Velocity and Size Distribution of Droplets Produced by an Impinging Liquid Jet

基于自行搭建的撞击式射流系统,采用高速摄影技术和三维相位多普勒技术,实现对撞击式射流不同工况下破碎模式及破碎速度场、粒度场分布规律的联合测量.结果表明,随着喷射压力升高,轴向速度w增大并在各压力下呈对称性分布,径向速度v在零附近,索特平均直径(SMD)逐渐减小并且无量纲的平均直径(SMD/D)收敛于0.13;相同压力下X-Z平面上,沿喷雾向下游发展的方向,w逐渐减小,径向速度u的绝对值减小且对称性下降;随着撞击夹角从60°增大到120°,u、w以及SMD逐渐减小;粒径分布符合Rosin-Rammler粒径分布函数.

High-speed photography and 3D phase Doppler system were used to obtain the breakup regime, velocity and size distribution under various working conditions of an impinging liquid jet. Results show that with the increase of injection pressure, the axial velocity is increased and presents a symmetri- cal distribution at each pressure, the radial velocity is near zero, SMD is decreased and SMD/D con- verges to 0.13. Along the downstream direction of the X-Z plane, axial velocity is gradually decreased, the absolute value of radial velocity and symmetry are decreased. When impinging jet angle 20 increases from 60 to 120, axial and radial velocities and SMD decrease gradually. Size distribution fits the Rosin- Rammler function.