多喷嘴对置式撞击流反应器流场的数值模拟

为探讨多股撞击流反应器内流场的特点，利用Fluent软件对两喷嘴对置式和四喷嘴对置式撞击流反应器内流场进行模拟，研究了在不同工况下这两种撞击流反应器内的流场结构，设定进口流速分别为5 m/s、10 m/s、15 m/s、20 m/s、25 m/s。模拟结果表明，进口流速由5 m/s增加到25 m/s时，反应器内流体流动的平均速度及压力波动增大为原来的4.1倍和16.2倍，其速度梯度和压力平均波幅也增大为原来的5.0倍和25.4倍。通过对两种不同结构的撞击流反应器的比较可以得到四喷嘴对置式撞击流反应器内流体流动产生的速度梯度和压力平均波幅更大，其值都约为二喷嘴对置式撞击流反应器的1.2倍，因而四喷嘴对置式撞击流反应器内剪切力场更强，脉动更强烈，更有利于反应器内的湍动混合。

Numerical simulation of the flow field in multi-nozzle opposed imping stream reactor

In order to discuss the characteristics of the flow field in the Multiple impinging stream reactor，the flow field of the two nozzles opposed imping stream reactor and four nozzles opposed imping stream reactor under the different conditions were simulated by Fluent software. The import velocities were set as 5 m/s、10 m/s、15 m/s、20 m/s and 25 m/s. The simulation results showed that the average of flow velocity and the fluctuation of pressure increased to 4.1 times and 16.2 times，and the velocity gradient and the average of amplitude of pressure increased to 5.0 times and 25.4 times when the import velocity increased from 5 m/s to 25 m/s. The comparison of the two reactors indicated that greater average of velocity gradient and higher average of volatility of pressure were generated in the four nozzles opposed imping stream reactor. Both values were 1.2 times of that in the two nozzles opposed imping stream reactor，indicating that both shear force field and pulsation were more powerful in the four nozzles opposed imping stream reactor，more favorable for turbulent mixing within the reactor.