scholarly journals Viscous liquid films on a porous vertical cylinder: Dynamics and stability

2013 ◽  
Vol 25 (6) ◽  
pp. 064101 ◽  
Author(s):  
Zijing Ding ◽  
Teck Neng Wong ◽  
Rong Liu ◽  
Qiusheng Liu
Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6529
Author(s):  
Krystian Czernek ◽  
Stanisław Witczak

The paper presents the characteristics of the original optoelectronic system for measuring the values of hydrodynamics of two-phase downward gas-very viscous liquid flow. The measurement methods and results of the research on selected values describing gas–oil two-phase flow are presented. The study was conducted in vertical pipes with diameters of 12.5, 16, 22, and 54 mm. The research was conducted with the superficial velocities of air jg = 0–29.9 m/s and oil jl = 0–0.254 m/s, which corresponded to the values of gas stream density gg = (0–37.31) kg/(m2s) and of liquid gl = (0.61–226.87) kg/(m2s), in order to determine the influence of air and oil streams on the character of liquid films. The variations in oil viscosity were applied in the range ηl = (0.055–1.517) Pas. The study results that were obtained with optical probes along with computer image analysis system revealed vast research opportunities in terms of the identification of gas–liquid two-phase downward flow structures that were generated as well as the determination of the thickness of liquid film with various level of interfacial surface area undulation. The designed and constructed proprietary measuring system is also useful for testing the liquid layer by determining the parameters of the resulting waves. It is considered that the apparatus system that is presented in the article is the most effective in examining the properties of liquid layers of oil and other liquids with low electrical conductivity and a significant degree of monochromatic light absorption. In view of noninvasive technique of measuring characteristic values of liquid films being formed, the above measuring system is believed to be very useful for industry in the diagnostics of the apparatus employing such flows.


2006 ◽  
Vol 28 (4) ◽  
pp. 219-224
Author(s):  
Phan Thi Thu Phuong ◽  
Tran Van Tran

In this paper, the problem of linear stability of viscous liquid films down an inclined plane is solved by finite difference method. It is applicable for moderate values of Reynolds and wave numbers. The obtained results by this method is compared with ones of some papers and with experimental data.


2014 ◽  
Vol 9 (1) ◽  
pp. 70-78
Author(s):  
Oleg Volodin ◽  
Aleksandr Pavlenko ◽  
Nikolay Pecherkin ◽  
Vladimir Serdyukov

The paper presents the experimental results on heat transfer in films falling down the vertical cylinder with mesh coating in a wide range of Reynolds’ number (30–270). The mixture of freons R21 and R114 as well as the pure R21 were used as working liquids. The features of heat transfer in falling liquid films on the surface with wire mesh coating compared with the smooth surface have been revealed. It is shown that the heat transfer coefficient at evaporation on the surface with mesh coating is somewhat higher than on the smooth surface; and the nucleate boiling develops earlier on the surface with such a coating. The influence of the initial mixture composition on the coefficient of heat transfer is negligible at evaporation and boiling of binary mixture of freons with close saturation temperatures


1993 ◽  
Vol 160 (1) ◽  
pp. 218-225 ◽  
Author(s):  
Mikel L. Forcada ◽  
C.Mathew Mate

1988 ◽  
Vol 22 (6) ◽  
pp. 885-893 ◽  
Author(s):  
E. A. Demekhin ◽  
M. A. Kaplan ◽  
V. Ya. Shkadov

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