Numerical Simulation and Analysis Comparison of Various Post-mixed Abrasive Water Jet Nozzle
-
摘要: 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。Abstract: 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.
-
Key words:
- mixing uniformity /
- jet energy /
- numerical simulation /
- abrasive speed /
- abrasive volume fraction
-
表 1 喷嘴几何参数
Table 1. Geometrical parameters of nozzle
mm d1 d2 d3 d4 L1 L2 L3 4 24 6 4 35 30 50 注:α=33.4° 表 2 网格无关性证明
Table 2. The proof of grid independence
网格数量/万 出口速度/(m·s−1) 偏差/% 20 ~ 30 61.24 1.575 30 ~ 40 61.87 0.563 40 ~ 50 62.13 0.145 50 ~ 60 62.29 0.113 表 3
$ \rho {v_2^2} $ 值的结果统计表Table 3. The statistical table of
$\rho {v_2^2} $ valueskg/(m·s2) 喷嘴 最大值/
106最小值/
103均值/
106方差/
1012磨料侧进式喷嘴 3.6 340 2.3 1.2 磨料中进式喷嘴 5.3 2.5 1.7 4.3 改进的磨料中进式喷嘴 5.9 2.4 1.9 4.9 -
[1] 李晓红, 卢义玉, 向文英. 水射流理论及在矿业工程中的应用[M]. 重庆: 重庆大学出版社, 2007.LI X H, LU Y Y, XIANG W Y. Water jet theory and its application in mining engineering[M]. Chongqing: Chongqing University Press, 2007. (in Chinese) [2] DU M M, WANG H J, DONG H Y, et al. Numerical research on multi-particle movements and nozzle wear involved in abrasive waterjet machining[J]. The International Journal of Advanced Manufacturing Technology, 2021, 117(9-10): 2845-2858. doi: 10.1007/s00170-021-07876-9 [3] KUMAR A, GUPTA T V K, JHA R K, et al. Wear analysis of abrasive waterjet nozzle using suprathreshold stochastic resonance technique[J]. Proceedings of the Institution of Mechanical Engineers, Part E:Journal of Process Mechanical Engineering, 2021, 235(2): 499-504. doi: 10.1177/0954408920968354 [4] 刘国勇, 王宽宽, 陈欣欣, 等. 后混合磨料水射流除鳞喷嘴内部流场数值模拟[J]. 工程科学学报, 2015, 37(S1): 29-34.LIU G Y, WANG K K, CHEN X X, et al. Numerical simulation of internal flow field for post-mixed abrasive water jet descaling nozzle[J]. Chinese Journal of Engineering, 2015, 37(S1): 29-34. (in Chinese) [5] 黄飞, 胡斌, 左伟芹, 等. 不同形状喷嘴的高压水射流冲击力特性实验[J]. 重庆大学学报, 2019, 42(9): 123-132.HUANG F, HU B, ZUO W Q, et al. Experiments on the impact pressure of high-pressure water jet under different nozzle shapes[J]. Journal of Chongqing University, 2019, 42(9): 123-132. (in Chinese) [6] 姚仁太, 郭栋鹏, 杨秋林, 等. 计算流体力学基础与STAR-CD工程应用[M]. 北京: 国防工业出版社, 2015.YAO R T, GUO D P, YANG Q L, et al. Fundamentals of computational fluid dynamics and STAR-CD engineering application[M]. Beijing: National Defense Industry Press, 2015. (in Chinese) [7] 田家林, 胡志超, 刘松, 等. 磨料水射流仿真分析与试验研究[J]. 流体机械, 2021, 49(2): 8-13.TIAN J L, HU Z C, LIU S, et al. Simulation analysis and experimental research of abrasive water jet[J]. Fluid Machinery, 2021, 49(2): 8-13. (in Chinese) [8] FICKO M, BEGIC-HAJDAREVIC D, COHODAR HUSIC M, et al. Prediction of surface roughness of an abrasive water jet cut using an artificial neural network[J]. Materials, 2021, 14(11): 3108. doi: 10.3390/ma14113108 [9] ILUKHINA A A, KOLPAKOV V I, VELTISHCHEV V V, et al. The development of a physico-mathematical model for the functioning of an underwater waterjet cutting machine[J]. Moscow University Physics Bulletin, 2020, 75(2): 167-174. doi: 10.3103/S0027134920020058 [10] QIANG Z R, WU M P, MIAO X J, et al. CFD research on particle movement and nozzle wear in the abrasive water jet cutting head[J]. The International Journal of Advanced Manufacturing Technology, 2018, 95(9): 4091-4100. [11] 陈冰冰, 张立, 闫如忠. 磨料射流喷嘴压力场与速度场的研究[J]. 组合机床与自动化加工技术, 2020(1): 47-50.CHEN B B, ZHANG L, YAN R Z. Study on pressure field and velocity field of abrasive jet nozzle[J]. Modular Machine Tool & Automatic Manufacturing Technique, 2020(1): 47-50. (in Chinese) [12] 杨友胜, 张建平, 聂松林. 水射流喷嘴能量损失研究[J]. 机械工程学报, 2013, 49(2): 139-145. doi: 10.3901/JME.2013.02.139YANG Y S, ZHANG J P, NIE S L. Energy loss of nozzles in water jet system[J]. Journal of Mechanical Engineering, 2013, 49(2): 139-145. (in Chinese) doi: 10.3901/JME.2013.02.139 [13] 郭子豪, 傅连东. 基于数值模拟的高压磨料射流喷嘴流场分析及结构优化[J]. 武汉科技大学学报, 2020, 43(3): 201-207.GUO Z H, FU L D. Flow field analysis and structural optimization of high-pressure abrasive jet nozzle based on numerical simulation[J]. Journal of Wuhan University of Science and Technology, 2020, 43(3): 201-207. (in Chinese) [14] 徐启文. 前混合磨料射流外部流场的数值模拟与实验研究[D]. 徐州: 中国矿业大学, 2019.XU Q W. Numerical simulation and experimental research on external flow field of abrasive water suspension jet[D]. Xuzhou: China University of Mining and Technology, 2019. (in Chinese) [15] 管华双, 姜晨, 李佳音, 等. 微通道反应器沟槽底面的磨料水射流抛光研究[J]. 流体机械, 2021, 49(3): 8-13.GUAN H S, JIANG C, LI J Y, et al. Research on abrasive waterjet polishing of groove bottom surface in microchannel reactor[J]. Fluid Machinery, 2021, 49(3): 8-13. (in Chinese) [16] 杨欢, 侯荣国, 吕哲, 等. 多物理场作用下磁场辅助微细磨料水射流流场数值模拟[J]. 机床与液压, 2019, 47(11): 151-154.YANG H, HOU R G, LV Z, et al. Numerical simulation of micro abrasive water jet flow field assisted by magnetic field under action of multi-physics field[J]. Machine Tool & Hydraulics, 2019, 47(11): 151-154. (in Chinese) [17] CHEUNG C F, WANG C J, CAO Z C, et al. Development of a multi-jet polishing process for inner surface finishing[J]. Precision Engineering, 2018, 52: 112-121. doi: 10.1016/j.precisioneng.2017.11.018 [18] 张滕飞, 邓松圣, 陈晓晨, 等. 后混磨料射流颗粒运动仿真和实验分析[J]. 重庆理工大学学报(自然科学), 2015, 29(2): 57-60.ZHANG T F, DENG S S, CHEN X C, et al. Simulation and analysis of post-mixed abrasive water jet particle trajectory[J]. Journal of Chongqing University of Technology (Natural Science), 2015, 29(2): 57-60. (in Chinese)