幂律流体撞击式射流破碎特征试验

Experiment on the Breakup Characteristics of Impinging Jets of Power Law Fluid

基于自行搭建的撞击式射流系统,采用高速摄影技术研究了非对称条件下幂律流体黏度对撞击式射流破碎特征的影响规律.结果表明:随着幂律流体黏度的增加,射流破碎模式种类增加;除弓形液线模式外,其余模式开始出现的速度与流体黏度成正比;在射流速度v较低时,破碎长度Lbu与流体黏度成反比;两股不同黏度流体撞击时,Lbu随v呈'双峰模式'且在较高v时与流体黏度成正比;相同黏度撞击时,则呈'单峰模式'且在较高v时Lbu最大;喷雾锥角α随v增加而增大,最后趋于的稳定值与流体黏度成反比;v较高时,α与流体黏度成反比.

Based on self-built impinging jet system, high-speed photographing technology was used to study the effect of power law fluid viscosity on the breakup characteristics in asymmetric impinging jets. The results indicate that with the increase of the viscosity of power law fluid, the categories of spray patterns increase; the velocity in which each spray pattern occurs is proportional to the viscosity of fluid, except for bow-shaped pattern. At lower jet velocity v, breakup length Lbu is inversely proportional to the fluid viscosity. In case of impingement of two jets with different viscosities, Lbu is in a bimodal pattem and proportional to the viscosity of fluid in a range of higher velocity; in the case of the impingement of two jets with the same viscosity, Lbu is in a unimodal pattern and reaches the largest value in the range of higher velocity. The spray cone angle a increases with the increment of v and then tends to arrive at a stable value, which is inversely proportional to the fluid viscosity; in the range of higher velocity, o：is inversely proportional to fluid viscosity.