Formation of confined free film in the window on a vertical perforated plate

Xie Hanguang; Hu Jianguang; Wang Cheng; Dai Gance

doi:10.11729/syltlx20160197

Volume 31 Issue 5

Turn off MathJax

Article Contents

Article Navigation > Journal of Experiments in Fluid Mechanics > 2017 > 31(5): 32-38

Xie Hanguang, Hu Jianguang, Wang Cheng, et al. Formation of confined free film in the window on a vertical perforated plate[J]. Journal of Experiments in Fluid Mechanics, 2017, 31(5): 32-38. doi: 10.11729/syltlx20160197

Citation:

PDF( 4160 KB)

Formation of confined free film in the window on a vertical perforated plate

doi: 10.11729/syltlx20160197

State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China

Received Date: 2016-12-15
Rev Recd Date: 2017-08-23
Publish Date: 2017-10-25

Abstract

Abstract

Liquid film is a common contact way between gas/liquid and can be divided into wall-bounded film and free film according to the film formation process and the number of free surfaces. When a plate is perforated, both kinds of films exist. This paper describes some experimental observations of free-surface flows arising when a thin liquid film flows through the window on a vertical perforated plate. Dozens of rectangular windows (9~1152mm²) and six fluids (Ka from 52 to 3000) were used to investigate the flow mechanisms. Several typical flow patterns including pass-around flow, pass-through flow, bias flow and back-side flow are well defined under such a flow condition. Here a special focus is given to the window region, where various free-surface flow patterns composed of droplets, columns, sheets and their combinations were observed with increasing flow rate. Meantime, free film in the window is surface tension dominated and susceptible to disturbance, resulting in coalescence or break of liquid columns and films. At a critical flow rate, liquid film is able to full fill the window, forming a stable complete confined free film. Mutual influence between confined free film in the window region and wall-bounded film around shows special wavy trains, which is also called "twin liquid film". Based on experimental data and scaling analysis, an empirical equation which relates Reynolds number Re, Kapitza number Ka and a dimensionless length Nx is proposed to characterize the film formation conditions. It is found that critical film formation Reynolds number increases with Kapitz number and window size. And hysteresis phenomenon is manifested by obviously different flow transition Re for confined free film formation and breaking. The results can help window geometry optimization industrial processes to improve local heat and mass transfer. It can also enrich the traditional film flow investigations.
- twin-liquid film,
- flow transition,
- film formation,
- perforated plate

FullText(HTML)

References(28)

References

[1]	胡军, 胡国辉, 孙德军.沿平板下落薄膜流动的研究综述[J].力学进展, 2005, 35(2):161-169. doi: 10.6052/1000-0992-2005-2-J2004-109 Hu J, Hu G H, Sun D J. A review on thin films falling along an inclined plate[J]. Advances in Mechanics, 2005, 35(2):161-169. doi: 10.6052/1000-0992-2005-2-J2004-109
[2]	Batchelor G K, Moffatt H K, Worster M. Perspectives in fluid dynamics:a collective introduction to current research[M]. Cambridge:Cambridge University Press, 2002.
[3]	Kapitza P. Dynamic stability of the pendulum with vibrating suspension point[J]. Soviet Physics-JETP, 1951, 21(5):588-597. https://www.mendeley.com/research-papers/dynamic-stability-pendulum-vibrating-suspension-point/
[4]	Wasden F K, Dukler A E. A numerical study of mass transfer in free falling wavy films[J]. American Institute of Chemical Engineers Journal, 1990, 36(9):1379-1390. doi: 10.1002/(ISSN)1547-5905
[5]	Alekseenko S, Nakoryakov V E, Pokusaev B G. Wave flow of liquid films[M]. New York:Begell House, 1994.
[6]	Chang H-H, Demekhin E A. Complex wave dynamics on thin films[M]. Elsevier, 2002.
[7]	Kalliadasis S, Ruyer-Quil C, Scheid B, et al. Falling liquid films[M]. Springer Science & Business Media, 2011.
[8]	Squire H B. Investigation of the instability of a moving liquid film[J]. British Journal of Applied Physics, 1953, 4(6):167-169. doi: 10.1088/0508-3443/4/6/302
[9]	Brown D. A study of the behaviour of a thin sheet of moving liquid[J]. Journal of Fluid Mechanics, 1961, 10(2):297-305. doi: 10.1017/S002211206100024X
[10]	Lin S, Roberts G. Waves in a viscous liquid curtain[J]. Journal of Fluid Mechanics, 1981, 112:443-458. doi: 10.1017/S0022112081000505
[11]	Lin S P. Breakup of liquid sheets and jets[M]. England:Cambridge University Press Cambridge, England, 2003.
[12]	Sirignano W A, Mehring C. Review of theory of distortion and disintegration of liquid streams[J]. Progress in Energy & Combustion Science, 2000, 26(4):609-655. http://www.academia.edu/21244677/Review_of_theory_of_distortion_and_disintegration_of_liquid_streams
[13]	Pritchard W. Instability and chaotic behaviour in a free-surface flow[J]. Journal of Fluid Mechanics, 1986, 165:1-60. doi: 10.1017/S0022112086002987
[14]	Mackowiak J. Fluid dynamics of packed columns[M]. London, New York:Springer, 2010.
[15]	Fair J R, Seibert A F, Behrens M, et al. Structured packing performance experimental evaluation of two predictive models[J]. Industrial & Engineering Chemistry Research, 2000, 39(6):1788-1796. https://www.researchgate.net/publication/231394040_Structured_Packing_PerformanceExperimental_Evaluation_of_Two_Predictive_Models
[16]	Pavlenko A, Pecherkin N, Chekhovich V, et al. Hydrodynamics in falling liquid films on surfaces with complex geometry[J]. Microgravity Science and Technology, 2009, 21(1):207-213. doi: 10.1007/s12217-009-9157-1
[17]	Yao Y, Pavlenko A, Volodin O. Effects of layers and holes on performance of wire mesh packing[J]. Journal of Engineering Thermophysics, 2015, 24(3):222-236. doi: 10.1134/S1810232815030042
[18]	Kolev N, Kralev B, Kolev D. Gas side controlled mass transfer in a new packing with stamped horizontal lamellae operating at extremely low liquid loads[J]. Chemical Engineering and Processing:Process Intensification, 2013, 63:44-49. doi: 10.1016/j.cep.2012.07.004
[19]	戴干策, 胡剑光, 于建国, 等. 适应粘性吸收剂的有壁与无壁液膜交替的规整填料: 中国, 201210234334. 6. 2013-07-10. Dai G C, Hu J G, Yu J G, et al. Wall liquid film and wall-free liquid film alternate structured filler adapting to viscous absorbent:China, 201210234334.6. 2013-07-10.
[20]	Hu J, Liu J, Yu J, et al. CO₂ absorption into highly concentrated dea solution flowing over a vertical plate with rectangular windows[J]. International Journal of Greenhouse Gas Control, 2013, 19:13-18. doi: 10.1016/j.ijggc.2013.08.007
[21]	胡剑光, 刘佳特, 袁猛, 等.新型垂直板规整填料流体力学及传质性能[J].化工学报, 2014, 65(1):116-122. http://www.cnki.com.cn/Article/CJFDTOTAL-HGSZ201401019.htm Hu J G, Liu J T, Yuan M, et al. Hydrodynamics and mass transfer characteristics of a novel vertical-sheet structured packing[J]. Journal of Chemical Industry and Engineering, 2014, 65(1):116-122. http://www.cnki.com.cn/Article/CJFDTOTAL-HGSZ201401019.htm
[22]	王良生, 戴干策.圆盘反应器成膜性的持液量研究[J].化学反应工程与工艺, 2000, 16(2):127-135. http://www.cnki.com.cn/Article/CJFDTOTAL-HXFY200002005.htm Wang L S, Dai G C. A study of film forming and hold-up in a rotating disc-ring reactor[J]. Chemical Reaction Engineering and Technology, 2000, 16(2):127-135. http://www.cnki.com.cn/Article/CJFDTOTAL-HXFY200002005.htm
[23]	邓斌, 戴干策.圆盘反应器液膜表面更新数值模拟[J].化工学报, 2015, 66(4):1407-1416. doi: 10.11949/j.issn.0438-1157.20141688 Deng B, Dai G C. Numerical simulation of surface renewal frequency on vertically rotating disc[J]. Journal of Chemical Industry and Engineering, 2015, 66(4):1407-1416. doi: 10.11949/j.issn.0438-1157.20141688
[24]	Hu J, Yang X, Dai G. Numerical investigation on hydrodynamics of vertically confined free film[J]. The Canadian Journal of Chemical Engineering, 2016, 94(2):340-348. doi: 10.1002/cjce.v94.2
[25]	Oliver J F, Huh C, Mason S G. Resistance to spreading of liquids by sharp edges[J]. Journal of Colloid and Interface Science, 1977, 59(3):568-581. doi: 10.1016/0021-9797(77)90052-2
[26]	Brunet P, Flesselles J-M, Limat L. Dynamics of a circular array of liquid columns[J]. The European Physical Journal B, 2007, 55(3):297-322. doi: 10.1140/epjb/e2007-00057-y
[27]	Schmuki P, Laso M. On the stability of rivulet flow[J]. Journal of Fluid Mechanics, 1990, 215:125-143. doi: 10.1017/S0022112090002580
[28]	Ruan B, Jacobi A M, Li L. Effects of a countercurrent gas flow on falling-film mode transitions between horizontal tubes[J]. Experimental Thermal and Fluid Science, 2009, 33(8):1216-1225. doi: 10.1016/j.expthermflusci.2009.07.009