Effects of Nozzle Screw Structure on Breakup Length of Jet
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摘要: 使用高速相机研究了喷嘴螺纹结构对液体射流破裂长度的影响。采用5种不同直径(4.00、4.80、7.50、8.75、10.80 mm)的喷嘴进行实验,螺纹深度范围0.40~1.25 mm,液体射流雷诺数范围500~22 600。实验结果表明:当雷诺数小于1600时,液体射流破裂长度随着雷诺数的增加而增加,喷嘴螺纹结构对液体射流破裂长度的影响较小;随着雷诺数的增加,液体射流破裂长度先增加后减小,喷嘴螺纹结构的影响显著,带螺纹结构喷嘴的液体射流破裂长度小于光滑喷嘴的液体射流破裂长度;当雷诺数大于7000时,液体射流破裂长度随着雷诺数的增加而增加,喷嘴螺纹结构继续促进液体射流破裂长度的减小;同时,实验结果还表明喷嘴螺纹结构对小直径(直径小于5 mm)喷嘴的影响更显著。最后,以量纲为一螺纹深度、雷诺数和韦伯数为参数建立了液体射流破裂长度预测关系式。Abstract: The effects of nozzle screw structure on liquid jet breakup were investigated with a high-speed camera. Five nozzles with different diameters (4.00, 4.80, 7.50, 8.75 , 10.80 mm) were used in the experiment. The thread depth range was 0.40—1.25 mm, the liquid jet Reynolds number (Re) was within the scope of 500—22600, and the Weber number was within the scope of 0.0003—1.2000. The experimental results showed the screw structure had a strong disturbance to the jet and promoted the breakup of jet. By comparing the jet breakup length under different experimental conditions, it could be obtained that increasing Re led to the decrease of breakup length when Re<1 600. The structure of nozzle screw had little influence on the breakup length of liquid jet. The breakup length of liquid jet increased first and then decreased with Re raised. In this condition, the influence of screw structure of nozzle was significant, the breakup length was shorter than that of the smooth one. When Re>7 000, the breakup length of liquid jet rised with the increase of Re and the screw structure of nozzle continued to promote the decrease of the breakup length of liquid jet. The experimental results showed that the influence of nozzle screw structure on small diameter nozzle (diameter less than 5 mm) was more significant than that on the larger nozzle. By using dimensionless thread depth, Re and Weber number, the relationship for predicting the breakup length of liquid jet was established.
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Key words:
- breakup length /
- screw structure /
- thread depth /
- liquid jet /
- nozzle
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表 1 实验喷嘴尺寸
Table 1. Size of experimental nozzle
No. D/mm a /mm X 1 4.00 0 0 2 4.00 0.40 0.10 3 4.80 0 0 4 4.80 0.45 0.09 5 7.50 0 0 6 7.50 0.10 0.01 7 7.50 0.75 0.10 8 8.75 0 0 9 8.75 1.00 0.11 10 10.80 0 0 11 10.80 1.25 0.12 -
[1] LASHERAS J C, HOPFINGER E J. Liquid jet instability and atomization in a coaxial gas stream[J]. Annual Review of Fluid Mechanics, 1998, 32(1): 275-308. [2] DESHPANDE S S, GURJAR S R, TRUJILLO M F. A computational study of an atomizing liquid sheet[J]. Physics of Fluids, 2015, 27(8): 082018. [3] KANG Z, LI Q, CHENG P, et al. Effects of self-pulsation on the spray characteristics of gas-liquid swirl coaxial injector[J]. Acta Astronautica, 2016, 127: 249-259. doi: 10.1016/j.actaastro.2016.05.038 [4] 吴炬晖, 章文斌, 赵辉, 等. 表面活性剂对二次雾化袋状破裂特性的影响[J]. 华东理工大学学报(自然科学版), 2016, 42(3): 329-334. [5] MITCHELL B R, KLEWICKI J C, KORKOLIS Y P, et al. Normal impact force of Rayleigh jets[J]. Physical Review Fluids, 2019, 4(11): 113603. doi: 10.1103/PhysRevFluids.4.113603 [6] KOURMATZIS A, MASRI A R. Air-assisted atomization of liquid jets in varying levels of turbulence[J]. Journal of Fluid Mechanics, 2014, 764: 95-132. [7] RAYLEIGH L. On the instability of jets[J]. Proceedings of the London Mathematical Society, 1878, 10(1): 4-13. [8] WEBER C. Zum zerfall eines flüssigkeitsstrahles[J]. Zeitschrift fur Angewandte Mathematik und Mechanik, 1931, 11: 136-141. [9] LEFEBVRE A H. Atomization and Sprays[M]. New York: Hemisphere Publishing Corporation, 1988. [10] BIROUK M, LEKIC N. Liquid jet breakup in quiescent atmosphere: A review[J]. Atomization and Spray, 2009, 19(6): 501-528. doi: 10.1615/AtomizSpr.v19.i6.20 [11] 赵志伟, 苏永升. 不同出口角度扩压器的内部流动及离心压缩机级性能数值研究[J]. 华东理工大学学报(自然科学版), 2017, 43(2): 266-272. [12] 吴兆伟, 施浙杭, 赵辉, 等. 表面张力变化对含气泡液体射流破裂的影响[J]. 化工学报, 2021, 72(3): 1283-1294. [13] VAN HOEVE W, GEKLE S, SNOEIJER J H, et al. Breakup of diminutive Rayleigh jets[J]. Physics of Fluids, 2010, 22(12): 122003. doi: 10.1063/1.3524533 [14] ARAI M, AMAGAI K. Surface wave transition before breakup on a laminar liquid jet[J]. Internationl Journal of Heat and Fluid Flow, 1999, 20(5): 507-512. doi: 10.1016/S0142-727X(99)00039-9 [15] SALVADOR F J, RUIZ S, CRIALESI-ESPOSITO M, et al. Analysis on the effects of turbulent inflow conditions on spray primary atomization in the near-field by direct numerical simulation[J]. International Journal of Multiphase Flow, 2018, 102: 49-63. doi: 10.1016/j.ijmultiphaseflow.2018.01.019 [16] 石仲璟, 王学生, 陈琴珠. 乙氧基化反应喷嘴雾化和反应性能[J]. 华东理工大学学报(自然科学版), 2017, 43(2): 273-279. [17] MARMOTTANT P, VILLERMAUX E. On spray formation[J]. Journal of Fluid Mechanics, 2004, 498: 73-111. doi: 10.1017/S0022112003006529 [18] 李建昌, 李宏宇, 陈建, 等. 喷嘴结构对真空喷射雾化性能影响研究[J]. 真空科学与技术学报, 2014, 34(2): 101-105. doi: 10.3969/j.issn.1672-7126.2014.02.01 [19] ETZOLD M, DESWAL A, CHEN L, et al. Break-up length of liquid jets produced by short nozzles[J]. International Journal of Multiphase Flow, 2018, 99: 397-407. doi: 10.1016/j.ijmultiphaseflow.2017.11.006 [20] GONG C, OU M, JIA W. The effect of nozzle configuration on the evolution of jet surface structure[J]. Results in Physics, 2019, 15: 102572. doi: 10.1016/j.rinp.2019.102572 [21] LI Y, SISOEV G M, SHIKHMURZAEV Y D. On the breakup of spiralling liquid jets[J]. Journal of Fluid Mechanics, 2019, 862: 364-384. doi: 10.1017/jfm.2018.956 [22] UDDIN J, DECENT S P, SIMMONS M J H. Non-linear waves along a rotating non-Newtonian liquid jet[J]. International Journal of Engineering Science, 2008, 46(12): 1253-1265. doi: 10.1016/j.ijengsci.2008.06.016 [23] PĂRĂU E I, DECENT S P, KING A C, et al. Nonlinear travelling waves on a spiralling liquid jet[J]. Wave Motion, 2006, 43(7): 599-618. doi: 10.1016/j.wavemoti.2006.05.004 [24] DECENT S P, KING A C, SIMMONS M J H, et al. The trajectory and stability of a spiralling liquid jet: Viscous theory[J]. Applied Mathematical Modelling, 2009, 33(12): 4283-4302. doi: 10.1016/j.apm.2009.03.011 [25] SHIKHMURZAEV Y D, SISOEV G M. Spiralling liquid jets: Verifiable mathematical framework, trajectories and peristaltic waves[J]. Journal of Fluid Mechanics, 2017, 819: 352-400. doi: 10.1017/jfm.2017.169 [26] REZAYAT S, FARSHCHI M, GHORBANHOSEINI M. Primary breakup dynamics and spray characteristics of a rotary atomizer with radial-axial discharge channels[J]. International Journal of Multiphase Flow, 2019, 111: 315-338. doi: 10.1016/j.ijmultiphaseflow.2018.10.001 [27] LIU C, LIU F, YANG J, et al. Experimental investigations of spray generated by a pressure swirl atomizer[J]. Journal of the Energy Institute, 2019, 92(2): 210-221. doi: 10.1016/j.joei.2018.01.014 [28] SIKRORIA T, KUSHARI A. Experimental analysis and phenomenological model for liquid jet breakup in swirling flow of air[J]. Journal of Engineering for Gas Turbines and Power, 2019, 141(9): 091015. doi: 10.1115/1.4044060 [29] LU H, LIU H F, LI W F, et al. Bubble formation in an annular granular jet dispersed by a central air round jet[J]. AIChE Journal, 2013, 59(6): 1882-1893. doi: 10.1002/aic.13974 [30] 戴干策, 陈敏恒. 化工流体力学[M]. 北京: 化学工业出版社, 2005. [31] HASSLBERGER J, KETTERL S, KLEIN M, et al. Flow topologies in primary atomization of liquid jets: A direct numerical simulation analysis[J]. Journal of Fluid Mechanics, 2018, 859: 819-838. [32] EGGERS J, VILLERMAUX E. Physics of liquid jets[J]. Reports on Progress in Physics, 2008, 71(3): 036601. doi: 10.1088/0034-4885/71/3/036601 -