[1]沈超群,陈永平,施明恒.悬滴与卧滴合并行为特性[J].东南大学学报(自然科学版),2015,45(1):74-78.[doi:10.3969/j.issn.1001-0505.2015.01.014]
 Shen Chaoqun,Chen Yongping,Shi Mingheng.Coalescence characteristic of pendent and sessile droplets[J].Journal of Southeast University (Natural Science Edition),2015,45(1):74-78.[doi:10.3969/j.issn.1001-0505.2015.01.014]
点击复制

悬滴与卧滴合并行为特性()
分享到:

《东南大学学报(自然科学版)》[ISSN:1001-0505/CN:32-1178/N]

卷:
45
期数:
2015年第1期
页码:
74-78
栏目:
能源与动力工程
出版日期:
2015-01-20

文章信息/Info

Title:
Coalescence characteristic of pendent and sessile droplets
作者:
沈超群12陈永平13施明恒12
1东南大学能源热转换及其过程测控教育部重点实验室, 南京 210096; 2东南大学能源与环境学院, 南京 210096; 3扬州大学水利与能源动力工程学院, 扬州 225127
Author(s):
Shen Chaoqun12 Chen Yongping13 Shi Mingheng12
1Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, China
2School of Energy and Environment, Southeast University, Nanjing 210096, China
3School of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou 225127, China
关键词:
液滴 合并 流型 颈部断裂
Keywords:
droplet coalescence flow pattern neck pinch-off
分类号:
TK124
DOI:
10.3969/j.issn.1001-0505.2015.01.014
摘要:
基于VOF(volume of fluid)方法,建立了重力条件下悬滴与卧滴在空气中合并过程的理论模型,并进行数值模拟,研究了悬滴与卧滴的合并流型,并分析了不同Bond数下悬滴与卧滴的合并动力学行为.结果表明,悬滴与卧滴接触后,液滴间形成的液桥在表面张力的作用下快速扩展,在液桥与针头间出现颈缩现象;悬滴与卧滴合并过程存在“合并无断裂”和“合并后断裂”2种合并流型,当Bond数约为0.05时,合并流型由无断裂向断裂转变.随着Bond数增大,液滴合并后断裂的无量纲时间随之减小,当Bond数大于0.18,液滴合并后断裂的无量纲时间逐渐趋向定值.
Abstract:
A theoretical model of the coalescence process of pendent and sessile droplets via VOF(volume of fluid)method is developed and numerically analyzed to investigate the flow regime evolution and hydrodynamics of droplet coalescence under the gravity in air, particularly the droplet coalescence behaviors under different Bond numbers. The result indicates that, due to the surface tension, a liquid bridge forms and quickly expands when two kinds of droplets contact, and the neck appears and shrinks between the liquid bridge and needle tip. Two coalescence flow patterns, “coalescence with no pinch-off” and “coalescence with pinch-off”, are observed under different Bond numbers. The flow pattern changes from “coalescence with no pinch-off” into “coalescence with pinch-off” when Bond number is approximately 0.05. The dimensionless pinch-off time decreases with the rising Bond number and it turns to be constant if the Bond number is larger than 0.18.

参考文献/References:

[1] Whelpdale D M, List R. The coalescence process in raindrop growth [J]. Journal of Geophysical Research, 1971, 76(12): 2836-2856.
[2] Leach R N, Stevens F, Langford S C. Dropwise condensation—experiments and simulations of nucleation and growth of water drops in a cooling system [J]. Langmiur, 2006, 22(21): 8864-8872.
[3] Eggers J. Coalescence of spheres by surface diffusion [J]. Physical Review Letters, 1998, 80(12): 2634-2637.
[4] Christopher G F, Bergstein J, End N B,et al. Coalescence and splitting of confined droplets at microfluids junctions [J]. Lab on a Chip, 2009, 9(8): 1102-1109.
[5] Case S C, Nagel S R. Coalescence of low-viscosity liquids [J]. Physical Review Letters, 2008, 100(8): 084503-1-084503-4.
[6] Fezzaa K, Wang Y. Ultrafast X-ray phase-contrast imaging of the initial coalescence phase of two water droplets [J]. Physical Review Letters, 2008, 100(10): 104501-1-104501-4.
[7] Eggers J, Lister J R, Stone H A. Coalescence of liquid drops [J]. Journal of Fluid Mechanics, 1999, 401: 293-310.
[8] Thoroddsen S T, Takehara K, Etoh T G. The coalescence speed of a pendent and a sessile drop [J]. Journal of Fluid Mechanics, 2005, 527: 85-114.
[9] Wu M M, Cubaud T, Ho C M. Scaling law in liquid drop coalescence driven by surface tension [J]. Physics of Fluids, 2004, 16(7): L51-L54.
[10] Liao Q, Zhu X, Xing S M, et al. Visualization study on coalescence between pair of water drops on inclined surfaces [J]. Experimental Thermal and Fluid Science, 2008, 32(8): 1647-1654.
[11] 王四芳,兰忠,彭本利,等.超疏水表面液滴合并诱导弹跳现象分析[J].化工学报,2012,63(S1):17-22.
  Wang Sifang, Lan Zhong, Peng Benli,et al. Characteristics of droplet coalescence and self-propelling on superhydrophobic surface [J]. CIESC Journal, 2012, 63(S1): 17-22.(in Chinese)
[12] Duchemin L, Eggers J, Josserand C. Inviscid coalescence of drops [J]. Journal of Fluid Mechanics, 2003, 487: 167-178.
[13] Menchaca-Rocha A, Martinez-Davalos A, Nunez R,et al. Coalescence of liquid drops by surface tension [J]. Physical Review E, 2001, 63(4): 046309-1-046309-5.
[14] Yue P T, Zhou C F, Feng J J. A computational study of the coalescence between a drop and an interface in Newtonian and viscoelastic fluids [J]. Physics of Fluids, 2006, 18: 102102-1-102102-14.
[15] Blanchette F, Bigioni T P. Partial coalescence of drops at liquid interface [J]. Nature Physics, 2006, 2(4): 254-257.
[16] Mohammadi M, Shahhosseini S, Bayat M. Direct numerical simulation of water droplet coalescence in the oil[J]. International Journal of Heat and Fluid Flow, 2012, 36: 58-71.
[17] Hirt C W, Nichols B D. Volume of fluid(VOF)method for the dynamics of free boundaries [J]. Journal of Computational Physics, 1981, 39(1): 201-225.
[18] Brackbill J U, Kothe D B, Zemach C. A continuum method for modeling surface tension [J]. Journal of Computational Physics, 1992, 100(2): 335-354.

相似文献/References:

[1]施明恒.运动液滴的LEIDENFROST现象[J].东南大学学报(自然科学版),1985,15(3):83.[doi:10.3969/j.issn.1001-0505.1985.03.010]
 Shi Mingheng.The Leidenfrost Temperature of a falling Liquid Droplet[J].Journal of Southeast University (Natural Science Edition),1985,15(1):83.[doi:10.3969/j.issn.1001-0505.1985.03.010]
[2]王程遥,张程宾,陈永平,等.剪切流场下液滴碰撞的流变特性[J].东南大学学报(自然科学版),2015,45(2):309.[doi:10.3969/j.issn.1001-0505.2015.02.020]
 Wang Chengyao,Zhang Chengbin,Chen Yongping,et al.Rheological behavior of interactive drops in shear flow[J].Journal of Southeast University (Natural Science Edition),2015,45(1):309.[doi:10.3969/j.issn.1001-0505.2015.02.020]
[3]徐俊超,于燕,张军,等.液滴在燃煤细颗粒表面凝结的长大动力学特性[J].东南大学学报(自然科学版),2017,47(3):506.[doi:10.3969/j.issn.1001-0505.2017.03.016]
 Xu Junchao,Yu Yan,Zhang Jun,et al.Kinetics study of droplet growth on surface of coal-fired fine particles[J].Journal of Southeast University (Natural Science Edition),2017,47(1):506.[doi:10.3969/j.issn.1001-0505.2017.03.016]

备注/Memo

备注/Memo:
收稿日期: 2014-08-20.
作者简介: 沈超群(1984—),男,博士生;陈永平(联系人),男,博士,教授,博士生导师,ypchen@seu.edu.cn.
基金项目: 国家自然科学基金资助项目(51222605,11190015)、江苏省杰出青年基金资助项目(BK20130009).
引用本文: 沈超群,陈永平,施明恒.悬滴与卧滴合并行为特性[J].东南大学学报:自然科学版,2015,45(1):74-78. [doi:10.3969/j.issn.1001-0505.2015.01.014]
更新日期/Last Update: 2015-01-20