The Breakup Length of Turbulent Liquid Jets

1977 ◽  
Vol 99 (2) ◽  
pp. 414-415 ◽  
Author(s):  
P. Lafrance
Keyword(s):  
Experimental Data ◽  
Statistical Distribution ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Capillary Instability ◽  
Turbulent Fluctuations ◽  
Breakup Length ◽  
Comparison With Experimental Data

A formula for the statistical distribution of the breakup length of a turbulent liquid jet is derived. The formula is based on a model in which random turbulent fluctuations are amplified by capillary instability. A comparison with experimental data is made.

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.

scholarly journals Breakup of the Water Sheet Formed by Two Liquid Impinging Jets

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Yakang Xia ◽  
Lyes Khezzar ◽  
Shrinivas Bojanampati ◽  
Arman Molki
Keyword(s):  
Weber Number ◽  
Reynolds Numbers ◽  
Impinging Jets ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Impingement Angle ◽  
Number Range ◽  
Breakup Length ◽  
Sheet Breakup ◽  
Visualization Experiments

Flow visualization experiments are carried out to study the flow regimes and breakup length of the water sheet generated by two impinging liquid jets from an atomizer made of two identical tubes 0.686 mm in diameter. These experiments cover liquid jet Reynolds numbers based on the pipe diameter in the range of 1541 to 5394. The effects of the jet velocities and impingement angle between the two jets on the breakup performance are studied. Four spray patterns are recognized, which are presheet formation, smooth sheet, ruffled sheet, and open-rim sheet regimes. Water sheet breakup length is found to be consistent with previous experimental and theoretical results in the lower Weber number (based on water jet diameter and velocity) range. In the relatively high Weber number range, the breakup length tends to a constant value with increasing Weber number, and some discrepancies between experimental and theoretical predictions do exist. Measured water sheet area increases with increasing liquid jet Reynolds numbers and impingement angle within the range of the current study.

Numerical Simulation of Breakup of Elliptical Liquid Jet in Still Air

2012 ◽  
Author(s):  
Ehsan Farvardin ◽  
Ali Dolatabadi
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Breakup Length ◽  
Aspect Ratios ◽  
Switching Phenomenon ◽  
Dimensional Simulation ◽  
Axis Switching ◽  
Recent Experimental Work

Numerical simulation of liquid jets ejecting from a set of elliptical jets with different aspect ratios between 1 (circular) to 3.85 is performed for several Weber numbers ranging 15 to 330. The axis-switching phenomenon and breakup length of the jets are characterized by means of a Volume of Fluid (VOF) method together with a dynamic mesh refinement model. This three dimensional simulation is compared with a recent experimental work and the results agree well. It is concluded that at Weber numbers less than 100, the breakup length of the liquid jet increases, reaches a peak and then decreases suddenly.

scholarly journals Simulation of Elliptical Liquid Jet Primary Breakup In Supersonic Crossflow

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yao-zhi Zhou ◽  
Feng Xiao ◽  
Qing-lian Li ◽  
Chen-yang Li
Keyword(s):  
Aspect Ratio ◽  
Penetration Depth ◽  
Horseshoe Vortex ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Breakup Length ◽  
Aspect Ratios ◽  
Primary Breakup ◽  
Elliptical Jet ◽  
Maximum Spreading

The study of elliptical liquid jets in supersonic flow in a Mach 2.0 is performed numerically. The primary breakup process of the elliptical liquid jet is simulated for a Weber number 223, liquid/gas flux momentum 4.0. The aspect ratios of elliptical geometries are set to be 0.25, 0.5, 1, 2, and 5. The results show a remarkable difference in liquid jet disintegration morphology at different aspect ratios. Under supersonic crossflow conditions, the elliptical liquid jet shows more breakup characteristics than the round liquid jet. As the aspect ratio grows, the penetration depth decreases. The elliptical liquid jet with AR=0.25 has the largest penetration depth in all cases. Moreover, the round jet has a maximum spreading angle of 50.2°. The changing trends of the column breakup length both x direction and y direction are similar. The elliptical jet at a lower aspect ratio has a shorter breakup length due to the narrower windward area. The liquid jet has a pair of larger horseshoe vortex structure and a wider wake region at a higher aspect ratio. Two pairs of reversal vortex pairs with obvious characteristics can be observed in all the simulations.

scholarly journals Unforced Rayleigh instability of an immersed liquid jet

2018 ◽  
Vol 32 ◽  
pp. 01009
Author(s):  
Claudiu Patrascu ◽  
Alina Chipaila ◽  
Corneliu Balan
Keyword(s):  
Liquid Jet ◽  
Drop Diameter ◽  
Rayleigh Instability ◽  
Capillary Instability ◽  
Breakup Length ◽  
Jet Breakup

Motivated by the occurrence of the injection of liquids in various technical processes, we study the capillary instability of a liquid jet surrounded by another liquid. The study focuses on the natural developing Rayleigh instability, hence without an imposed perturbation. We also point out the influence of viscosity on the main drop diameter, resulted after jet breakup, and on the breakup length itself. Modifications brought by a decrease of the capillary nozzle are also emphasized for a particular case.

Numerical Simulation of the Breakup of Elliptical Liquid Jet in Still Air

2013 ◽  
Vol 135 (7) ◽  
Author(s):  
Ehsan Farvardin ◽  
Ali Dolatabadi
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Liquid Jets ◽  
Liquid Jet ◽  
Breakup Length ◽  
Aspect Ratios ◽  
Switching Phenomenon ◽  
Dimensional Simulation ◽  
Axis Switching ◽  
Recent Experimental Work

The numerical simulation of liquid jets ejecting from a set of elliptical orifices with different aspect ratios between 1 (circular) and 3.85 is performed for several Weber numbers, ranging from 15 to 330. The axis-switching phenomenon and breakup length of the jets are characterized by means of a volume of fluid (VOF) method, together with a dynamic mesh refinement model. This three-dimensional simulation is compared with a recent experimental work and the results agree well. It is concluded that for Weber numbers ranging from 15 to 100, by increasing the Weber number, the breakup length of the liquid jet increases, reaches a peak, and then decreases suddenly.

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