Deformation and breakup behaviors of a drop in ambient liquid under impact
-
摘要: 采用基于液-液体系的坠落实验装置对冲击作用下单个液滴在环境液体中的变形破碎行为进行了实验研究。针对高速摄影捕捉到的5种液滴典型变形破碎模式进行了定量化考察和规律性分析。结果表明,液滴初始直径、液滴与环境液体的密度比和粘度比、界面张力系数以及坠落高度等实验参数相互组合可以得到相似的实验结果,其中We数是区分液滴变形破碎模式的关键参数。进一步研究液滴变形破碎模式与无量纲参数的依赖关系发现,在1 < We < 700、0.001 < Oh < 0.005的实验条件范围内,液滴变形破碎模式与Oh数无明显依赖关系,而在We数相近情况下,液滴变形破碎模式呈现明显的相似性。Abstract: In this study, we carry out an experimental investigation of the behaviors as well as the mechanism of the liquid-liquid drop deformation and breakup process following an impact. With high speed photography, five distinct deformation and breakup modes are captured, for which the key factors that dominate the transition are quantitatively analyzed. The results show that similar deformation behaviors may occur for a proper combination of drop sizes, density ratios between drop and ambient fluid, interfacial tensions and free falling heights. Two non-dimensional parameters, i.e. Weber number (We) and Ohnesorge number (Oh), are calculated to estimate these effects. It is found that, similar deformation behaviors may have a strong correlation with the Weber number. After a further survey of the test range of present study (1 < We < 700, 0.001 < Oh < 0.005), it can be concluded that the deformation and breakup pattern is barely affected by the Ohnesorge number, whereas exhibits a strong dependence on the Weber number.
-
Key words:
- liquid-liquid system /
- drop deformation and breakup /
- impact /
- high speed photography /
- Weber number /
- Ohnesorge number
-
图 8 液滴变形破碎模式之间的转变过程图像,上行:(a)袋状模式,(b)过渡模式,(c)帽状模式,(b*)过渡模式剖视图;下行:(d)帽状模式,(e)过渡模式,(f)竹节状模式,(e*)过渡模式剖视图
Figure 8. Transition between drop deformation and breakup modes, upper row: (a) bag mode, (b) transition mode, (c) cap mode, (b*) cross-sectional view of transition mode; lower row: (d) cap mode, (e) transition mode, (f) bamboo mode, (e*) Cross-sectional view of transition mode
表 1 液滴与环境液体的相关物性参数
Table 1. Related properties of drop and ambient fluid
Fluid type Density
/(g·cm-3)Viscosity
/(mPa·s)Interface tension coefficient
/(mN·m-1)Drop 1050~1630 0.6~2.4 14.49~25.01 Ambient fluid 1015~1035 2.8~4.6 表 2 液滴5种典型变形破碎模式所对应的实验条件
Table 2. Typical experimental conditions for five modes of drop deformation and breakup
Mode Fig.3 d0/mm ρd/ρa μd/μa σ/(mN·m-1) h/m A 7.2 1.129 0.705 25.01 0.3 B 6.0 1.170 0.296 16.50 0.8 C 6.0 1.170 0.296 16.50 1.5 D 4.3 1.523 0.202 15.49 0.6 E 4.7 1.567 0.142 14.69 1.3 Deformation Fig.5 d0/mm ρd/ρa μd/μa σ/(mN·m-1) h/m a1 6.0 1.170 0.296 16.50 0.60 a2 5.3 1.287 0.447 18.97 0.30 a3 5.0 1.434 0.352 18.62 0.15 b1 6.0 1.170 0.296 16.50 1.50 b2 6.2 1.344 0.417 18.63 0.50 b3 5.3 1.287 0.447 18.97 0.80 c1 4.3 1.523 0.202 15.49 0.60 c2 4.1 1.502 0.212 16.11 0.90 c3 4.2 1.563 0.161 14.69 0.60 -
[1] Lane W R. Shatter of drops in streams of air[J]. Ind Eng Chem, 1951, 43(6):1312-1317. doi: 10.1021/ie50498a022 [2] Hinze J O. Fundamentals of the hydrodynamic mechanism of splitting in dispersion processes[J]. AIChE Journal, 1955, 1(3):289-295. doi: 10.1002/(ISSN)1547-5905 [3] Hanson A R, Domich E G, Adams H S. Shock tube investigation of the breakup of drops by air blasts[J]. Phys Fluids, 1963, 6(8):1070-1080. doi: 10.1063/1.1706864 [4] Simpkins P G, Bales E L.Water-drop response to sudden acce-lerations[J]. J Fluid Mech, 1972, 55(4):629-639. doi: 10.1017/S0022112072002058 [5] Krzeczkowski S A. Measurement of liquid droplet disintegration mechanisms[J]. Int J Multiphase Flow, 1980, 6(3):227-239. doi: 10.1016/0301-9322(80)90013-0 [6] Wierzba A, Takayama K. Experimental investigation of the aerodynamic breakup of liquid drops[J]. AIAA Journal, 1988, 26(11):1329-1335. doi: 10.2514/3.10044 [7] Yoshida T, Takayama K. Interaction of liquid droplets with planar shock waves[J]. Trans ASME J Fluids Engng, 1990, 112(4):481-486. doi: 10.1115/1.2909431 [8] Wierzba A. Deformation and breakup of liquid drops in a gas stream at nearly critical Weber numbers[J]. Experiments in Fluids, 1990, 9(1):59-64. doi: 10.1007%2FBF00575336 [9] Hsiang L P, Faeth G M. Near-limit drop deformation and secondary breakup[J]. Int J Multiphase Flow, 1992, 18(5):635-652. doi: 10.1016/0301-9322(92)90036-G [10] Hsiang L P, Faeth G M. Drop properties after secondary breakup[J]. Int J Multiphase Flow, 1993, 19(5):721-735. doi: 10.1016/0301-9322(93)90039-W [11] Liu Z, Reitz R D. An analysis of the distorsion and breakup mechanisms of high speed liquid drops[J]. Int J Multiphase Flow, 1997, 23(4):631-650. doi: 10.1016/S0301-9322(96)00086-9 [12] Joseph D D, Belanger J, Beavers G S. Breakup of a liquid drop suddenly exposed to a high-speed airstream[J]. Int J Multiphase Flow, 1999, 25(6):1263-1303. https://www.researchgate.net/publication/222457588_Breakup_of_a_liquid_drop_suddenly_exposed_to_a_high-speed_airstream [13] Lee C H, Reitz R D. An experomental study of the effect of gas density on the distortion and breakup mechanism of drops in high speed gas stream[J]. Int J Multiphase Flow, 2000, 26(2):229-244. doi: 10.1016/S0301-9322(99)00020-8 [14] Joseph D D, Beavers G S, Funada T. Rayleigh-Taylor instability of viscoelastic drops at high Weber numbers[J]. J Fluid Mech, 2002, 453:109-132. https://www.researchgate.net/publication/231787206_Rayleigh-Taylor_instability_of_viscoelastic_drops_at_high_Weber_numbers [15] Theofanous T G, Li G J, Dinh T N. Aerobreakup in rarefied supersonic gas flows[J]. Trans ASME J Fluids Engng, 2004, 126(4):516-527. doi: 10.1115/1.1777234 [16] Theofanous T G, Li G J, Dinh T N, et al. Aerobreakup in disturbed subsonic and supersonic flow fields[J]. J Fluid Mech, 2007, 593:131-170. https://www.researchgate.net/profile/Guangjun_Li2/publication/232005867_Aerobreakup_in_disturbed_subsonic_and_supersonic_flow_fields/links/564216c908aebaaea1f8b869.pdf?origin=publication_detail [17] Theofanous T G, Li G. On the physics of aerobreakup[J]. Phys Fluids, 2008, 20(5):052103. doi: 10.1063/1.2907989 [18] Pilch M, Erdman C A. Use of breakup time data and velocity history data to predict the maximum size of stable fragments for acceleration-induced breakup of a liquid drop[J]. Int J Multiphase Flow, 1987, 13(6):741-757. doi: 10.1016/0301-9322(87)90063-2 [19] Gelfand B E. Droplet breakup phenomena in flows with velocity lag[J]. Progress in Energy and Combustion Science, 1996, 22(3):201-265. doi: 10.1016/S0360-1285(96)00005-6 [20] Guildenbecher D R, Lopez-Rivera C, Sojka P E. Secondary ato-mization[J]. Experiments in Fluids, 2009, 46(3):371-402. doi: 10.1007/s00348-008-0593-2 [21] Majithia A K, Hall S, Harper L, et al. Droplet breakup quantification and processes in constant and pulsed air flows[C]//Proceedings of the 22nd Conference on Liquid Atomization and Spray Systems (ILASS-Europe), Como Lake, Italy, 2008. [22] Kulkarni V, Sojka P E. Bag breakup of low viscosity drops in the presence of a continuous air jet[J]. Phys Fluids, 2014, 26(7):072103. doi: 10.1063/1.4887817 [23] Mohit J, Surya P R, Gaurav T, et al. Secondary breakup of a drop at moderate Weber numbers[J]. Proceedings of the Royal Society A, 2015, 147:20140930. https://www.researchgate.net/publication/276177709_Secondary_breakup_of_a_drop_at_moderate_Weber_numbers [24] Patel P D, Theofanous T G. Hydrodynamic fragmentation of drops[J]. J Fluid Mech, 1981, 103:307-323. http://www.osti.gov/scitech/biblio/5273464 [25] Hsiang L P, Faeth G M. Drop deformation and breakup due to shock wave and steady disturbances[J]. Int J Multiphase Flow, 1995, 21(4):545-560. doi: 10.1016/0301-9322(94)00095-2 [26] Landeau M, Deguen R, Olson P. Experiments on the fragmentation of a buoyant liquid volume in another liquid[J]. J Fluid Mech, 2014, 749:478-518. doi: 10.1017/jfm.2014.202 [27] 熊燃华, 许明, 李耀发, 等.液-液两相介质中液滴在冲击作用下的演变过程[J].中国科学:物理学力学天文学, 2010, 40(6):773-780. http://phys.scichina.com:8083/sciG/EN/Y2010/V40/I6/773Xiong R H, Xu M, Li Y F, et al. The deformation and breakup of a drop-in-liquid under an impact loading[J]. Science China Phys, Mech and Astron, 2010, 40(6):773-780. http://phys.scichina.com:8083/sciG/EN/Y2010/V40/I6/773 [28] Andreas J M, Hauser E A, Tucker W B. Boundary tension by pendant drops[J]. J Phys Chem, 1938, 42(8):1001-1019. http://www.researchgate.net/publication/231423689_Boundary_Tension_by_Pendant_Drops