EXPERIMENTAL INVESTIGATION OF THE DROP SIZE DISTRIBUTION OF SPRAYS PRODUCED BY A LOWVELOCITY NEWTONIAN CYLINDRICAL LIQUID JET

2001 ◽  
Vol 11 (3) ◽  
pp. 227-254 ◽  
Author(s):  
Helene Malot ◽  
Christophe Dumouchel
Keyword(s):  
Experimental Investigation ◽  
Size Distribution ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Liquid Jet

Note on the break-up of a charged liquid jet

1962 ◽  
Vol 13 (1) ◽  
pp. 151-157 ◽  
Author(s):  
R. H. Magarvey ◽  
L. E. Outhouse
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Point Of View ◽  
Liquid Jet ◽  
Disintegration Process ◽  
Photographic Evidence ◽  
Break Up

The disintegration of a charged liquid jet is examined, and the break-up mechanism inferred from photographic evidence. Gravitational, molecular and electrical forces all contribute to the segmentation of the jet and determine the drop size distribution. The disintegration process is investigated from the point of view of drop generation. The segmentation of the charged jet differs from the known ways in which an uncharged jet is broken into drops.

The viscous Savart sheet

2013 ◽  
Vol 730 ◽  
pp. 607-625 ◽  
Author(s):  
E. Villermaux ◽  
V. Pistre ◽  
H. Lhuissier
Keyword(s):  
Size Distribution ◽  
Model Experiment ◽  
Weber Number ◽  
Drop Size ◽  
Drop Size Distribution ◽  
Liquid Jet ◽  
Substantial Fraction

AbstractWe study the viscous version of the planar Savart sheet problem, using an impacting liquid jet up to 300 times more viscous than water. Two surprising observations are made, contrasting with the traditional case introduced by Savart where viscosity plays no role. First, if the radius of a viscous sheet is typically reduced compared to the case of water for a given jet radius and impacting velocity, the smooth–flapping transition is delayed, allowing for smooth sheet radii substantially bigger than those permitted with water at large impacting Weber number. Second, the drop size distribution is bimodal, with a substantial fraction of the drops having a very small, well-defined diameter. We understand these two facts in terms of an additional model experiment, and simple physical arguments.

The Impact of Density Ratio on the Liquid Core Dynamics of a Turbulent Liquid Jet Injected Into a Crossflow

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Marcus Herrmann ◽  
Marco Arienti ◽  
Marios Soteriou
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Density Ratio ◽  
Liquid Core ◽  
Drop Size Distribution ◽  
Liquid Jet ◽  
Ambient Conditions ◽  
Gas Density ◽  
Simulation Results ◽  
Jet Penetration

Atomizing liquids by injecting them into crossflows is a common approach in gas turbines and augmentors. Much of our current understanding of the processes resulting in atomization of the jets, the resulting jet penetration and spray drop size distribution have been obtained by performing laboratory experiments at ambient conditions. Yet, operating conditions under which jets in crossflows atomize can be far different from ambient. Hence, several dimensionless groups have been identified that are believed to determine jet penetration and resulting drop size distribution. These are usually the jet and crossflow Weber and Reynolds numbers and the momentum flux ratio. In this paper, we aim to answer the question of whether an additional dimensionless group, the liquid to gas density ratio must be matched. We perform detailed simulations of the primary atomization region using the refined level set grid (RLSG) method to track the motion of the liquid/gas phase interface. We employ a balanced force, interface projected curvature method to ensure high accuracy of the surface tension forces, use a multiscale approach to transfer broken off, small scale nearly spherical drops into a Lagrangian point particle description allowing for full two-way coupling and continued secondary atomization, and employ a dynamic Smagorinsky large eddy simulation (LES) approach in the single phase regions of the flow to describe turbulence. We present simulation results for a turbulent liquid jet (q=6.6, We=330, and Re=14,000) injected into a gaseous crossflow (Re=740,000) analyzed under ambient conditions (density ratio 816) experimentally by Brown and McDonnell [2006, “Near Field Behavior of a Liquid Jet in a Crossflow,” Proceedings of the ILASS Americas, 19th Annual Conference on Liquid Atomization and Spray Systems]. We compare simulation results obtained using a liquid to gas density ratio of 10 and 100. The results show that the increase in density ratio causes a noticeable increase in liquid core penetration with reduced bending and spreading in the transverse directions. The post-primary atomization spray penetrates further in both the jet and transverse direction. Results further show that the penetration correlations for the windward side trajectory commonly reported in the literature strongly depend on the value of threshold probability used to identify the leading edge. Correlations based on penetration of the jet’s liquid core center of mass, on the other hand, can provide a less ambiguous measure of jet penetration. Finally, the increase in density ratio results in a decrease in wavelength of the most dominant feature associated with a traveling wave along the jet as determined by proper orthogonal decomposition.

The Impact of Density Ratio on the Primary Atomization of a Turbulent Liquid Jet in Crossflow

2010 ◽  
Author(s):  
Marcus Herrmann ◽  
Marco Arienti ◽  
Marios Soteriou
Keyword(s):  
Size Distribution ◽  
Drop Size ◽  
Density Ratio ◽  
Liquid Core ◽  
Drop Size Distribution ◽  
Liquid Jet ◽  
Ambient Conditions ◽  
Gas Density ◽  
Simulation Results ◽  
Jet Penetration

Atomizing liquids by injecting them into crossflows is a common approach in gas turbines and augmentors. Much of our current understanding of the processes resulting in atomization of the jets, the resulting jet penetration and spray drop size distribution have been obtained by performing laboratory experiments at ambient conditions. Yet, operating conditions under which jets in crossflows atomize can be far different from ambient. Hence, several dimensionless groups have been identified that are believed to determine jet penetration and resulting drop size distribution. These are usually the jet and crossflow Weber and Reynolds numbers and the momentum flux ratio. In this paper we aim to answer the question of whether an additional dimensionless group, the liquid to gas density ratio must be matched. To answer this question, we perform detailed simulations of the primary atomization region using the Refined Level Set Grid (RLSG) method to track the motion of the liquid/gas phase interface. We employ a balanced force, interface projected curvature method to ensure high accuracy of the surface tension forces, use a multi-scale approach to transfer broken off, small scale nearly spherical drops into a Lagrangian point particle description allowing for full two-way coupling and continued secondary atomization, and employ a dynamic Smagorinsky large eddy simulation (LES) approach in the single phase regions of the flow to describe turbulence. We present simulation results for a turbulent liquid jet (q = 6.6, We = 330, Re = 14,000) injected into a gaseous crossflow (Re = 740,000) analyzed under ambient conditions (density ratio 816) experimentally by Brown and McDonnel (2006). We compare simulation results obtained using a liquid to gas density ratio of 10 to those obtained using a density ratio of 100, a value typical for gas turbine combustors. The results show that the increase in density ratio results in a notice-able increase in liquid core penetration with reduced bending in the crossflow and spreading in the transverse directions. The post-primary atomization spray, however, penetrates further in both the jet and transverse direction. Results further show that penetration correlations for the windward side trajectory commonly reported in the literature strongly depend on the value of threshold probability used to identify the leading edge. Correlations based on the penetration of the jet’s liquid core center of mass, on the other hand, can provide a less ambiguous measure of jet penetration. Finally, the increase in density ratio results in a decrease in wavelength of the most dominant feature associated with a traveling wave along the jet as determined by proper orthogonal decomposition.

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