管道对称性对后混合磨料水射流喷嘴流场的影响

The effect of pipe symmetry on nozzle flow field of post mixed abrasive water jet

为了研究磨料管道的对称性对后混合磨料水射流的混合效果及射流速度的影响,通过改变磨料管道的对称性,设计了4组(单喷嘴、1组对称、2组对称、环形)磨料管道对称性不同、其余参数均相同的后混合喷嘴,并在相同的流场边界条件下对其进行了模拟分析。结果表明:磨料管道非对称喷嘴的磨料混合效果最差,磨料集中偏向于磨料来流侧,高速水流的能量损失较大;磨料管对称型喷嘴明显改善了磨料与高速水流的混合均匀性和提高了磨料水射流的流速,沿中轴线的最大水射流速度分别是非对称型喷嘴的1.1倍,1.2倍,1.3倍左右,在距喷嘴出口4 mm截面的磨料水射流平均速度是非对称型喷嘴的1.20倍,1.27倍,1.29倍左右。该仿真计算结果可较好地为喷嘴的设计和加工提供理论参考。

In order to study the effect for the symmetry of the abrasive pipe on the mixing effect and jet velocity of the post-mixed abrasive water jet,by changing the symmetry of the abrasive pipe,four groups of abrasive pipes(single nozzle,1 group of symmetric pipes,2 groups of symmetric annular pipes)were designed.The post-mixing nozzles with different symmetry and the same other parameters were simulated and analyzed under the same flow field boundary conditions.The results show that the abrasive mixing effect of a asymmetric nozzle is the worst,the abrasive is concentrated on the side of the abrasive incoming flow,the energy loss of the high speed water flow is relatively big;the symmetrical abrasive pipe nozzle significantly improves the mixing uniformity of the abrasive and high speed water flow and speed of abrasive water jet.The maximum water jet velocity along the central axis is about 1.1 times,1.2 times,and 1.3 times that of the asymmetric nozzle,the average velocity of abrasive water jet in the section 4 mm away from the nozzle outlet is about 1.20 times,1.27 times,and 1.29 times that of asymmetric nozzles.The simulation calculation results can provide a theoretical reference for nozzle design and processing.