Insight of hydrodynamic characteristics related to ultra-high pressure water jet rust removal sprayers
-
摘要: 基于对超高压水射流喷头的外部参数定量化分析，给出关于射流核心参数的优选方法，旨在提高水射流效率。首先，根据超高压水射流除锈喷嘴的工作特点，考虑到水的压缩性和空化效应，建立单束定冲角、多束旋转喷头的三维数值模型，通过改变靶距、入射角度、转速等外部特征参数，实施了超高压水射流除锈喷头水动力性能模拟研究。然后，重点分析单束定冲角喷嘴靶距、入射角度对靶面剪切应力、打击压强分布的影响，以及射流等速核长度与最佳射流靶距的关系。发现当靶距等于喷嘴射流等速核长度时，壁面剪切应力达到最佳水平。此外，通过分析高速旋转射流卷吸效应、靶面水垫作用对靶面所受剪切应力、打击压强分布的影响，得到最佳转速范围和对应线速度。初步阐明了射流冲击剥离的机理、单束定冲角以及多束旋转射流的特征参数对射流效果的影响，可为超高压除锈喷头的设计、装配提供参考。Abstract: Based on the quantitative analysis of the external parameters in relation to ultra-high pressure water jet sprayers, an optimal method for the key parameters of water jets was proposed, aiming at improving the efficiency of the water jets. Firstly, according to the characteristics of the ultra-high pressure water jet rust removal nozzles, the three-dimensional models of the single-beam and rotating multi-beam nozzles were established and used for the numerical simulations in which taking the water compressibility and cavitation effects into account. By changing the relevant characteristic parameters, such as standoff distances, jet angles and rotating speeds, the hydrodynamic performances related to the ultra-high pressure water jet rust removal nozzles were investigated though the simulations. Secondly, the effects of the standoff distances and jet angles for the single-beam nozzle on the distributions of the wall shear stress and impact pressure as well as the relationship between the length of the potential core of the jet and the optimal standoff distance were analyzed. Results show that the wall shear stress reaches its maximum value when the standoff distance is equal to the length of the potential core of a jet. Finally, by analyzing the effects of entrainment and water cushion on the distributions of the wall shear stress and impact pressure, the optimal rotating speed and corresponding linear speed were obtained. The research results preliminarily clarify the rust removal mechanism of the water jet and the effect of the characteristic parameters related to the single-beam nozzle and rotating multi-beam nozzle on the jet effect, and can provide references for the design and assembly of an ultra-high pressure rust removal equipment.
-
Key words:
- ultra-high pressure water jet /
- hydrodynamic /
- jet angle /
- standoff distance /
- rotating speed
-
图 1 直锥型喷嘴以及水射流结构示意图
Figure 1. Schematic diagram of the straight cone nozzle structure and water jet structure
图 2 单束定冲角喷头三维模型和网格拓扑结构剖面图
Figure 2. The three-dimensional model and cross-section mesh topology for the single-beam nozzle with a fixed angle of attack
图 3 单束定冲角喷头射流计算域示意图
Figure 3. The computational domain of the impinging jet from the single-beam nozzle with a fixed angle of attack
图 4 多束旋转喷头实物、模拟模型及对应的三维网格拓扑结构
Figure 4. The photo and simulation model of the rotating multi-beam nozzle as well as its corresponding three-dimension mesh topology
图 5 单喷嘴射流模型计算域各物理量云图
Figure 5. Contours of different physical quantities in the computational domain of the single-beam nozzle with a fixed angle of attack
图 6 斜冲击射流流场速度、壁面剪切应力云图
Figure 6. Contours of the oblique impinging jet velocity and wall shear stress
图 8 不同冲击角度下，壁面剪切应力分布
Figure 8. Wall shear stress distributions at different jet angles
图 9 收敛角30°时不同靶距下的壁面打击压强分布
Figure 9. Wall pressure distributions at different standoff distances with a convergence angle of 30°
图 10 收敛角30°时不同靶距下的壁面剪切应力分布
Figure 10. Wall shear stress distributions at different standoff distances with a convergence angle of 30°
图 11 收敛角40°时不同靶距下的壁面打击压强分布
Figure 11. Wall pressure distributions at different standoff distances with a convergence angle of 40°
图 12 收敛角40°时不同靶距下的壁面剪切应力分布
Figure 12. Wall shear stress distributions at different standoff distances with a convergence angle of 40°
图 13 收敛角120°时不同靶距下的壁面打击压强分布
Figure 13. Wall pressure distributions at different standoff distances with a convergence angle of 120°
图 14 收敛角120°时不同靶距下的壁面剪切应力分布
Figure 14. Wall shear stress distributions at different standoff distances with a convergence angle of 120°
图 15 不同收敛角下，射流轴心速度分布
Figure 15. Jet axial velocity distributions at different convergence angles
图 16 不同转速下，射流流场速度和壁面剪切应力云图
Figure 16. Contours of impinging jet velocity and wall shear stress at different rotating speeds
图 17 多束旋转喷头的射流效果图（0 r/min）
Figure 17. Jet effect diagram of a multi-beam rotating nozzle (0 r/min)
图 18 不同转速下壁面打击压力分布
Figure 18. Wall pressure distributions at different rotating speeds
表 1 网格敏感性验证
Table 1. Mesh sensitivity validation
网络编号 网格节点 壁面打击压强/MPa δ/% Mesh 1 402 324 198.29 Mesh 2 721 127 198.99 0.353 Mesh 3 1 058 945 199.37 0.191 Mesh 4 1 684 043 199.40 0.015 
下载: 导出CSV
-
[1] ROBINSON SMART D S. Experimental investigation of effect of abrasive jet nozzle position and angle on coating removal rate [J]. International Journal of Manufacturing Systems, 2011, 1(1): 57–64. DOI: 10.3923/ijmsaj.2011.57.64. [2] 王兴如. 基于超高压纯水射流的船壁除锈除漆关键技术与爬壁试验研究 [D]. 辽宁大连: 大连海事大学, 2010. DOI: 10.7666/d.y1837002.WANG X R. The key technology and climbing wall experiments study of the ship rust removal based on ultrahigh pressure pure water jet [D]. Dalian, Liaoning, China: Dalian Maritime University, 2010. DOI: 10.7666/d.y1837002. [3] 薛胜雄. 超高压水射流自动爬壁除锈机理与成套设备技术 [D]. 杭州: 浙江大学, 2005.XUE S X. Studies on the removal rust forming by UHP waterjetting auto-robot and its unit technology [D]. Hangzhou, Zhejiang, China: Zhejiang University, 2005. [4] PENG H J, ZHANG P. Numerical simulation of high speed rotating waterjet flow field in a semi enclosed vacuum chamber [J]. Computer Modeling in Engineering & Sciences, 2018, 114(1): 59–73. DOI: 10.3970/cmes.2018.114.059. [5] 张子威, 刘会景, 孙鹏飞, 等. 管道射流清洗喷嘴流场的数值模拟与分析 [J]. 煤炭工程, 2017, 49(5): 115–118. DOI: 10.11799/ce201705034.ZHANG Z W, LIU H J, SUN P F, et al. Numerical simulation and analysis on flow field of jet nozzle for cleaning pipe [J]. Coal Engineering, 2017, 49(5): 115–118. DOI: 10.11799/ce201705034. [6] 施春燕, 袁家虎, 伍凡, 等. 冲击角度对射流抛光中材料去除面形的影响分析 [J]. 光学学报, 2010, 30(2): 513–517. DOI: 10.3788/AOS20103002.0513.SHI C Y, YUAN J H, WU F, et al. Influence analysis of impact angle on material removal profile in fluid jet polishing [J]. Acta Optica Sinica, 2010, 30(2): 513–517. DOI: 10.3788/AOS20103002.0513. [7] 王丽萍, 蔡晓君, 窦艳涛, 等. 高压水射流清洗参数实验研究 [J]. 实验室研究与探索, 2017, 36(8): 48–51. DOI: 10.3969/j.issn.1006-7167.2017.08.011.WANG L P, CAI X J, DOU Y T, et al. Experimental research of high pressure water jet cleaning parameters [J]. Research and Exploration in Laboratory, 2017, 36(8): 48–51. DOI: 10.3969/j.issn.1006-7167.2017.08.011. [8] 罗银川, 李秀龙, 张杨, 等. 射流抛光中的流场特性研究 [J]. 光学技术, 2015, 40(4): 376–380. DOI: 10.13741/j.cnki.11-1879/o4.2014.04.020.LUO Y C, LI X L, ZHANG Y, et al. Analysis of flow field characteristics in fluid jet polishing [J]. Optical Technique, 2015, 40(4): 376–380. DOI: 10.13741/j.cnki.11-1879/o4.2014.04.020. [9] GE Z L, WANG L, WANG M, et al. Rock-breaking properties under the rotatory impact of water jets in water jet drilling [J]. Applied Sciences, 2019, 9(24): 5417. DOI: 10.3390/app9245417. [10] WEN J W, CHEN C, CAMPOS U. Experimental research on the performances of water jet devices and proposing the parameters of borehole hydraulic mining for oil shale [J]. PLoS One, 2018, 13(6): e0199027. DOI: 10.1371/journal.pone.0199027. [11] 屈长龙. 基于船舶除锈爬壁机器人的高压水射流仿真研究及实验验证 [D]. 广州: 华南理工大学, 2016.QU C L. The simulation research and experimental verification on high pressure water jet based on wall climbing robot for hull rust removal [D]. Guangzhou, Guangdong, China: South China University of Technology, 2016. [12] 孙家骏. 水射流切割技术 [M]. 江苏徐州: 中国矿业大学出版社, 1992. [13] 王正钦. 旋转喷头的数值模拟及参数研究 [D]. 北京: 北京科技大学, 2007.WANG Z Q. Numerical simulation of rotating nozzle and its parameters research [D]. Beijing, China: University of Science and Technology Beijing, 2007. [14] SOM S, AGGARWAL S K, EL-HANNOUNY E M, et al. Investigation of nozzle flow and cavitation characteristics in a diesel injector [J]. Journal of Engineering for Gas Turbines and Power, 2010, 132(4): 042802. DOI: 10.1115/1.3203146. [15] 王迪. 高压水射流清洗的仿真研究及实验验证 [D]. 哈尔滨: 哈尔滨工业大学, 2014. DOI: 10.7666/d.D591195.WANG D. The simulation research and experimental verification on high pressure water jet cleaning [D]. Harbin, Heilongjiang, China: Harbin Institute of Technology, 2014. DOI: 10.7666/d.D591195. [16] 薛梅新, 吴迪, 朴英. 高压喷嘴内部空化流动的数值模拟研究 [J]. 工程力学, 2012, 29(10): 46–51. DOI: 10.6052/j.issn.1000-4750.2010.11.0822.XUE M X, WU D, PIAO Y. Numerical simulation of internal flow and cavitation of a diesel nozzle [J]. Engineering Mechanics, 2012, 29(10): 46–51. DOI: 10.6052/j.issn.1000-4750.2010.11.0822. [17] 刘辉, 马辉运, 曾立新, 等. 自旋转射流除垢喷头研制与性能测试 [J]. 钻采工艺, 2020, 43(S1): 72–75.LIU H, MA H Y, ZENG L X, et al. Development of self-rotating jet nozzle for scale removal and its performance test [J]. Drilling & Production Technology, 2020, 43(S1): 72–75. [18] 王正钦, 管华, 刘庭成. 高压水射流清洗技术中的旋转喷头 [J]. 清洗世界, 2007, 23(1): 31–34,38. DOI: 10.3969/j.issn.1671-8909.2007.01.008.WANG Z Q, GUAN H, LIU T C. Rotating nozzle for high pressure water-jet cleaning technology [J]. Cleaning World, 2007, 23(1): 31–34,38. DOI: 10.3969/j.issn.1671-8909.2007.01.008. -
点击查看大图
计量
- 文章访问数: 326
- HTML全文浏览量: 159
- PDF下载量: 48
- 被引次数: 0