多种后混合磨料水射流喷嘴的数值模拟及分析比较

Numerical Simulation and Analysis Comparison of Various Post-mixed Abrasive Water Jet Nozzle

针对传统的后混合磨料水射流喷嘴中的磨料与水混合均匀性差,磨料射流能量低的问题。本文基于CFD欧拉多相流模型,利用Fluent软件对比磨料侧进式喷嘴、磨料中进式喷嘴以及改进的磨料中进式喷嘴在相同边界条件下计算得到的内外流场结果。分析结果表明:磨料侧进式喷嘴的磨料主要分布在速度较低的区域,未能进入高速水流内部,导致喷嘴内外流场的中心位置磨料射流能量低,磨料与水混合均匀性差;磨料中进式喷嘴很好的解决了磨料不能进入高速水流内部的问题,磨料体积分数和磨料速度从中心向外逐渐减小,射流效果明显改善;改进的磨料中进式喷嘴减小了高速水流在原磨料中进式喷嘴混合腔内的碰撞损耗,磨料在外流场的速度及动能都有一定提高。

Because of poor mixing uniformity and low jet energy of abrasive water in the traditional post-mixed abrasive water jet nozzle,the paper uses the CFD Euler multiphase flow model and the Fluent software to analyze and compare the abrasive side-feed nozzle,the abrasive medium-feed type and the improved abrasive medium-feed nozzle.The analysis results show that the abrasive water of the abrasive side-feed nozzle is mainly distributed in the low-velocity area and fails to enter into the high-speed water stream,resulting in poor mixing uniformity and low jet energy.The abrasive medium-feed nozzle solves the problem that abrasive water enters into the high-speed water stream and that the abrasive volume fraction and abrasive velocity gradually decrease from the center to the outside,significantly improving the jet effect.The improved abrasive inlet nozzle reduces the collision loss of the high-speed water flow in the original abrasive inlet nozzle's mixing chamber,somewhat increasing the speed and kinetic energy of the abrasive water in the external flow field.