脉冲防暴水炮出口段射流的大涡模拟

为优化装备设计,减少实验投入,采用大涡模拟方法耦合二维非稳态VOF模型对脉冲防暴水炮发射管内及出口段的气液两相射流进行了数值模拟研究.通过搭建实验台对脉冲防暴水炮出口段射流进行了高速摄影实验,并利用高速图像记录系统自带的判读软件对射流出口段的速度值进行了判读,实验所得的射流形状及速度与仿真结果吻合较好.利用仿真方案进行变运动参数的数值模拟,结果表明:初始压力对出口速度影响较大,而初始射角对出口速度大小没有影响,因改变了初始射流方向,导致最大射程有所变化.研究表明较大的初始压力和较小的水量能获得更大的射流出口速度和更少的水炮发射时间.

Large Eddy Simulation of Nozzle Water-jet of Pulsed Anti-riots Water Cannon

In order to optimize the design of equipment, and reduce the investment in experiment expense, a large eddy simulation method coupling with 2-D unsteady VOF model is adopted to simulate the gas-liquid water-jet in and around the nozzle of pulsed anti-riots water cannon. After the setting up of experiment tape, the high-speed photography technology is adopted to photo the water jet around the nozzle, and then the velocity reader software is used to gain the velocity of the outside water-jet. Compared with the numerical result, the obtained experiment water-jet figure and velocity are in better accord with the simulation results. By using the said method to do the simulation of changing numerical parameters, the initial pressure has significant influence on the velocity of water-jet, but the initial launch angle has little influence on the velocity of water-jet, which only affect the biggest cannon-shot. The study results show that with bigger initial pressure and smaller initial water quantity, bigger water-jet velocity and shorter launch time can be obtained. The conclusion achieved is of some guide sense to the optimization of design of water cannon.