The Effect of a Flat-plate-Type Obstacle on the Thin Liquid Film Accompanied by a High Speed Gas Flow

Measurements and predictions of three-dimensional shear driven thin liquid films by turbulent air flow in a duct are reported. FLUENT - CFD code is used to perform the numerical simulations and the Reynolds Averaged Navier-Stokes and continuity equations along with the Volume of Fluid (VOF) model and the realizable k-ε turbulence model are implemented for this task. Film thickness and width are reported as a function of air flow rate, liquid film volume flow rate and surface tension, and a comparison with preliminary measured results is made. The thickness of the shear driven liquid film is measured using an interferometric technique that makes use of the phase shift between the reflection of incident light from the top and bottom surfaces of the thin liquid film. The spatial resolution is determined based on the spot size of the incident light, which for the current configuration of the transmitting optics is approximately 10 microns. The resulting fringe pattern is imaged using a high-speed imaging camera operating at 2000 frames per second. The technique has proved successful in measuring thickness between 100 and 900 microns in these shear driven films. Simulation results reveal that higher gas flow velocity decreases the film thickness but increases its width, while higher liquid film flow rate increases the film thickness and increases its width. Reasonable comparison appears to exist between preliminary measured and simulated results.

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Measurement of thin liquid film drainage using a novel high-speed impedance analyzer

Review of Scientific Instruments ◽

10.1063/1.1149088 ◽

1998 ◽

Vol 69 (9) ◽

pp. 3232-3239 ◽

Cited By ~ 4

Author(s):

Kevin O. Hool ◽

Robert C. Saunders ◽

Harry J. Ploehn

Keyword(s):

Liquid Film ◽

High Speed ◽

Thin Liquid Film ◽

Impedance Analyzer ◽

Film Drainage

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A Comparison of Oil-Water Flow and Oil-Gas Flow in Capillary Model

Volume 4: Dynamics, Control and Uncertainty, Parts A and B ◽

10.1115/imece2012-87720 ◽

2012 ◽

Cited By ~ 1

Author(s):

Yihe Zhang ◽

Liming Dai

Keyword(s):

Pressure Drop ◽

Liquid Film ◽

Gas Flow ◽

Capillary Flow ◽

Flow Behavior ◽

Thin Liquid Film ◽

Flow Process ◽

Capillary Model ◽

Oil Water ◽

Oil Gas

A capillary model is employed to study the slug flow behavior in pore structure. Oil-water system and oil-gas system are investigated in the experiments. During the flow process, it is observed that the wetting phase liquid will generate a thin liquid film on the inner surface of the tube wall, and the liquid film plays an important role in capillary flow. At the meantime, the pressure drop across the tube is recorded during the experiment, result shows that the pressure drop magnitude is proportional to the oil slug length, while it is not significantly affected by the liquid injecting velocity.

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Use of a thin liquid film moving under the action of gas flow in a mini-channel for removing high heat fluxes

MATEC Web of Conferences ◽

10.1051/matecconf/201792010037 ◽

2016 ◽

Vol 92 ◽

pp. 01037 ◽

Cited By ~ 4

Author(s):

Dmitry Zaitsev ◽

Egor Tkachenko ◽

Evgeniy Orlik ◽

Oleg Kabov

Keyword(s):

Liquid Film ◽

Gas Flow ◽

Thin Liquid Film ◽

High Heat ◽

Heat Fluxes

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Precursor Film Formation Process Ahead Macroscopic Contact Line of Spreading Droplet on Smooth Substrate

ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer, Volume 2 ◽

10.1115/mnhmt2009-18314 ◽

2009 ◽

Author(s):

Ichiro Ueno ◽

Kanji Hirose ◽

Yusuke Kizaki ◽

Yoshiaki Kisara ◽

Yoshizumi Fukuhara

Keyword(s):

Liquid Film ◽

Contact Line ◽

Formation Process ◽

High Speed ◽

Thin Liquid Film ◽

Solid Substrate ◽

Precursor Film ◽

Boundary Line ◽

Brewster Angle Microscopy ◽

Droplet Spreading

The authors pay their special attention to formation process of wafer-thin liquid film, known as ‘precursor film,’ ahead moving macroscopic contact line of a droplet spreading on a solid substrate. The spreading droplet on the solid substrate is accompanied with the movement of a visible boundary line so-called ‘macroscopic contact line.’ Existing studies have indicated there exits a thin liquid film known as ‘precursor film’ ahead the macroscopic contact line of the droplet. The present author’s group has dedicated their special effort to detect the formation process of the precursor film by applying a convectional laser interferometry and a high-speed camera, and to evaluate the spreading rate of the precursor film. In the present study, existing length of the precursor film at a very early stage of the droplet spreading is evaluated by applying a Brewster-angle microscopy as well as the interferometer. The authors extend their attention to the advancing process of the precursor film on inclined substrate.

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Simulating nonlinear waves on the surface of thin liquid film entrained by turbulent gas flow

Thermophysics and Aeromechanics ◽

10.1134/s0869864315020067 ◽

2015 ◽

Vol 22 (2) ◽

pp. 191-202 ◽

Cited By ~ 9

Author(s):

I. S. Vozhakov ◽

D. G. Arkhipov ◽

O. Yu. Tsvelodub

Keyword(s):

Liquid Film ◽

Nonlinear Waves ◽

Gas Flow ◽

Thin Liquid Film ◽

Turbulent Gas Flow

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Design of Solid Rocket Engine

Volume 4: 20th Design for Manufacturing and the Life Cycle Conference; 9th International Conference on Micro- and Nanosystems ◽

10.1115/detc2015-48092 ◽

2015 ◽

Author(s):

Ryoichi S. Amano ◽

Yi-Hsin Yen

Keyword(s):

Liquid Film ◽

High Speed ◽

Gas Flow ◽

Volume Fraction ◽

Length Scale ◽

Breakup Process ◽

Flow Conditions ◽

Solid Rocket Motor ◽

Breakup Length ◽

Solid Rocket

This paper presents both experiment and simulation of alumina molten flow in a solid rocket motor (SRM), when the propellant combusts, the aluminum is oxidized into alumina (Al2O3) which, under the right flow conditions, tends to agglomerate into molten droplets, impinge on the chamber walls, and then flow along the nozzle wall. Such agglomerates can cause erosive damage. The goal of the present study is to characterize the agglomerate flow within the nozzle section by studying the breakup process of a liquid film that flows along the wall of a straight channel while a high-speed gas moves over it. We have used an unsteady-flow Reynolds-Averaged Navier-Stokes code (URANS) to investigate the interaction of the liquid film flow with the gas flow, and analyzed the breakup process for different flow conditions. The rate of the wave breakup was characterized by introducing a breakup-length-scale for various flow conditions based on the Volume Fraction (VF) of the liquid, which is an indicator of a two-phase flow liquid breakup level. A smaller breakup-length-scale means that smaller drops have been created during the breakup process. The study covers the breakup and fluid behaviors based on different gas-liquid momentum flux ratios, different surface tension and viscosity settings, different Ohnesorge numbers (Oh), and different Weber numbers. Both water and molten aluminum flows were considered in the simulation studies. The analysis demonstrates an effective method of correlating the liquid breakup with the main flow conditions in the nozzle channel path.

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