Influence of Jet Velocity on Jet Breakup in Immiscible Liquid-Liquid Systems

2009 ◽  
Vol 4 (3) ◽  
Author(s):  
Chi M Phan ◽  
Geoffrey M Evans
Keyword(s):  
Droplet Size ◽  
High Speed ◽  
Immiscible Liquid ◽  
Linear Instability ◽  
Liquid Jets ◽  
Instability Analysis ◽  
Jet Breakup ◽  
Liquid Systems ◽  
Jet Velocity ◽  
Simplified Solution

The breakup of a laminar liquid jet is the underling phenomena used to generate emulsions in micro-scale devices. Jet breakup is induced by the most unstable disturbance growing on the jet surface, and linear instability analysis can be utilized to predict the resultant droplet size. Previously, instability analysis has been applied to stationary jets at intermediate Re only. This study investigates the influence of the jet velocity on the jet breakup at low Re number. The breakups of moving liquid jets were monitored using a high speed camera. The jet diameter, jet breakup length and resultant droplet sizes were strongly influenced by jet velocity. In addition to a simplified solution, a linear analysis for a moving jet was developed to determine the resultant droplet size. It was found that the full analysis is required to correctly predict the droplet size at low Re number.

scholarly journals Effects of Asymmetric Gas Distribution on the Instability of a Plane Power-Law Liquid Jet

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1854 ◽  
Author(s):  
Jin-Peng Guo ◽  
Yi-Bo Wang ◽  
Fu-Qiang Bai ◽  
Fan Zhang ◽  
Qing Du
Keyword(s):  
Power Law ◽  
Liquid Velocity ◽  
Linear Instability ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Critical Curves ◽  
Jet Breakup ◽  
Plane Jets ◽  
Gas Space ◽  
Aerodynamic Asymmetry

As a kind of non-Newtonian fluid with special rheological features, the study of the breakup of power-law liquid jets has drawn more interest due to its extensive engineering applications. This paper investigated the effect of gas media confinement and asymmetry on the instability of power-law plane jets by linear instability analysis. The gas asymmetric conditions mainly result from unequal gas media thickness and aerodynamic forces on both sides of a liquid jet. The results show a limited gas space will strengthen the interaction between gas and liquid and destabilize the power-law liquid jet. Power-law fluid is easier to disintegrate into droplets in asymmetric gas medium than that in the symmetric case. The aerodynamic asymmetry destabilizes para-sinuous mode, whereas stabilizes para-varicose mode. For a large Weber number, the aerodynamic asymmetry plays a more significant role on jet instability compared with boundary asymmetry. The para-sinuous mode is always responsible for the jet breakup in the asymmetric gas media. With a larger gas density or higher liquid velocity, the aerodynamic asymmetry could dramatically promote liquid disintegration. Finally, the influence of two asymmetry distributions on the unstable range was analyzed and the critical curves were obtained to distinguish unstable regimes and stable regimes.

Study on some Aspects of Breakup Characteristics of Power-Law Fluid with Impinging Jets Based on Mechanics Properties

2012 ◽  
Vol 625 ◽  
pp. 57-60
Author(s):  
En Dong Wang ◽  
Yan Yin ◽  
Qing Du
Keyword(s):  
Power Law ◽  
High Speed ◽  
Wave Length ◽  
Impinging Jets ◽  
Liquid Sheet ◽  
Liquid Jets ◽  
Power Law Fluid ◽  
Round Jets ◽  
Breakup Length ◽  
Jet Velocity

Shear-thinning power-law fluid is a kind of non-Newtonian fluid in which the viscosity is a function of shear rate. Impinging jets system is used to study the breakup characteristics of power-law liquid sheets formed by two symmetrical round jets in this study. High quality images are obtained from the experiment with a high speed camera and breakup length is extracted from the images. Closed-rim sheet, web-like sheet and ligaments sheet are observed with the increase of jet velocity. A series of images show that the wave length on the surface of sheets tends to decline as the jet velocity increases. At a low We number, the breakup length increases with an increasing We number. However, it first increases and then decreases when the liquid sheet breaks up at a high We number. The liquid jets with larger diameter collide to each other and lead to a liquid sheet with a smaller breakup length.

scholarly journals UTILIZATION OF SODIUM SULFIT DROPLET FOR OXYGEN ABSORPTION

2020 ◽  
Vol 41 (2) ◽  
pp. 89-94
Author(s):  
Anda Lucia
Keyword(s):  
Mass Transfer ◽  
Droplet Size ◽  
High Speed ◽  
Gas Absorption ◽  
Chemical System ◽  
Oxygen Absorption ◽  
Liquid Droplets ◽  
Gas Cleaning ◽  
Liquid Systems ◽  
Coeffi Cients

Gas absorption by liquid droplets in a spray column is one common method for gas cleaning. The simple design, low pressure drop, and the possibility of its application in liquid systems containing solids are benefi ts of this method. The mass transfer coeffi cient of gas-liquid absorption depends on droplet size, concentration of liquid or gas and the physic-chemical system. Experiments to study the mass transfer using the air-oxygen/sulphite system have been performed. The dispersed droplets were generated by pumping the liquid through a needle with certain fl owrate. A High Speed Camera with shadowgraph method and image processing was used for measurement of droplet size and velocity accurately. The shapes of the droplets were relatively not spherical because of oscillating movement. The droplets are slightly accelerated after detach from the needle. The oxygen concentrations were determined by means of spectrophotometric method. The liquid mass transfer coeffi cients of this experiment are 2 times lower than the model because of the low reaction between oxygen and sulphite . The mass transfer coeffi cient of the experiment is calculated from the experimental data, and compared with the model equations from the literature.

Visualization of Supersonic Non-Newtonian Liquid Jets

2012 ◽  
Vol 187 ◽  
pp. 63-67
Author(s):  
Anirut Matthujak ◽  
Chaidet Kasamnimitporn ◽  
Wuttichai Sittiwong ◽  
Kulachate Pianthong
Keyword(s):  
High Speed ◽  
Ambient Air ◽  
Video Camera ◽  
Newtonian Liquid ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Dynamic Behaviors ◽  
Penetration Distance ◽  
Jet Penetration ◽  
Jet Velocity

This paper describes the characteristics of supersonic non-Newtonian liquid jets injected in ambient air. The main focus is to visualize three types of time-independent non-Newtonian liquid jet and to describe their behaviors. Moreover, comparisons between their dynamic behaviors with Newtonian liquid jet are reported. The supersonic liquid jets are generated by impact driven method in a horizontal single-stage power gun. Jets have been visualized by the high speed digital video camera and shadowgraph method. Effects of different liquid types on the jet penetration distance, average jet velocity and other characteristics have been examined. From shadowgraph images, the unique dynamic behaviors of each non-Newtonian liquid jets are observed and found obviously different from that of the Newtonian liquid jet. The maximum average jet velocity of 1,802.18 m/s (Mach no. 5.30) has been obtained. The jet penetration distance and average velocity are significantly varied when the liquid types are different.

A laboratory study of recovery boiler smelt shattering

TAPPI Journal ◽  
2014 ◽  
Vol 13 (8) ◽  
pp. 19-26 ◽  
Author(s):  
ANTON TARANENKO ◽  
MARKUS BUSSMANN ◽  
HONGHI TRAN
Keyword(s):  
Droplet Size ◽  
Flow Rate ◽  
Liquid Flow ◽  
High Speed ◽  
Liquid Flow Rate ◽  
Liquid Viscosity ◽  
Experimental Apparatus ◽  
Nozzle Position ◽  
Jet Velocity ◽  
Recovery Boiler

A scaled-down experimental apparatus was built to examine smelt shattering during typical recovery boiler operations. Water-glycerine solutions and air were used in place of smelt and steam. A high-speed camera and image processing software were used to record and quantify liquid shattering in terms of droplet number and size distributions, as a function of air velocity, air nozzle position, liquid flow rate, and liquid viscosity. The results showed that increasing shatter jet velocity reduced average droplet size, increasing the liquid flow rate increased droplet size, and placing the shatter jet nozzle closer to the liquid stream decreased droplet size. These results were all as expected. The effect of liquid viscosity (1-50 cP) depended on the shatter jet velocity. At high air velocities, even the viscous liquid was well shattered, but at lower velocities, the effect of viscosity on shattering was significant.

Condensation on Coherent Turbulent Liquid Jets: Part I—Experimental Study

1989 ◽  
Vol 111 (4) ◽  
pp. 1068-1074 ◽  
Author(s):  
S. Kim ◽  
A. F. Mills
Keyword(s):  
Surface Tension ◽  
High Speed ◽  
Reynolds Numbers ◽  
Liquid Jets ◽  
High Speed Photography ◽  
Turbulence Level ◽  
Jet Breakup ◽  
Glass Tubes ◽  
Initial Turbulence ◽  
Jet Velocities

Condensation on coherent turbulent liquid jets was investigated experimentally in order to obtain a data base for the liquid side heat transfer coefficient. Jet breakup was identified by means of high-speed photography. Nozzles were formed from smooth and roughened glass tubes to define the initial turbulence level in the jets. Jet diameters of 3–7 mm and lengths of 2–12 cm were tested at jet velocities of 1.4–12 m/s giving Reynolds numbers of 6000–40,000. Viscosity and surface tension were varied by using ethanol, and water from 277–300 K, as test liquids. The Stanton number was found to be essentially independent of jet diameter, but to decrease with length to the power of −0.57, velocity to the power of −0.20, surface tension to the power of −0.30, and viscosity to the power of −0.1.

Simulation of Laminar Liquid Jets in Gaseous Crossflow Before the Onset of Primary Breakup

2011 ◽  
Author(s):  
C.-L. Ng ◽  
K. A. Sallam
Keyword(s):  
Experimental Data ◽  
Fuel Injection ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Jet Breakup ◽  
Primary Breakup ◽  
Density Ratios ◽  
First Time ◽  
Two Sides ◽  
Reduced Pressures

The deformation of laminar liquid jets in gaseous crossflow before the onset of primary breakup is studied motivated by its application to fuel injection in jet afterburners and agricultural sprays, among others. Three crossflow Weber numbers that represent three different liquid jet breakup regimes; column, bag, and shear breakup regimes, were studied at large liquid/gas density ratios and small Ohnesorge numbers. In each case the liquid jet was simulated from the jet exit and ended before the location where the experimental data indicated the onset of breakup. The results show that in column and bag breakup, the reduced pressures along the sides of the jet cause the liquid to move to the sides of the jet and enhance the jet deformation. In shear breakup, the flattened upwind surface pushes the liquid towards the two sides of the jet and causing the gaseous crossflow to separate near the edges of the liquid jet thus preventing further deformation before the onset of breakup. It was also found out that in shear breakup regime, the liquid phase velocity inside the liquid jet was large enough to cause onset of ligament formation along the jet side, which was not the case in the column and bag breakup regimes. In bag breakup, downwind surface waves were observed to grow along the sides of the liquid jet triggered a complimentary experimental study that confirmed the existence of those waves for the first time.

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