A comment on self-similar breakup for inertialess Newtonian liquid jets

As gel propellants are increasingly used in rocket engines, non-Newtonian liquid atomization has emerged as a research subject of great interest. This paper addresses the atomization of flat sheets of aqueous xanthan gum solution, which are formed from two jets ejected from impinging injectors. Based on the experimental photos, it has been found that gel liquid sheets do not break up directly into droplets that can be characterized as spheres with Sauter mean diameter; instead, a mass of ligaments is observed. Therefore, this paper will introduce fractal dimension as a new parameter, related to the quality of atomization under these experimental conditions; and a power-law correlation between fractal dimension and Reynolds number of liquid jets has been achieved.

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A Numerical Study on Flow Characteristics of 2D Vertical Liquid Jet Striking a Horizontal Surface

ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, Volume 3 ◽

10.1115/esda2010-25136 ◽

2010 ◽

Author(s):

M. Kimiaghalam ◽

M. Passandideh-Fard

Keyword(s):

Reynolds Number ◽

Hydraulic Jump ◽

Numerical Study ◽

Flow Characteristics ◽

Newtonian Liquid ◽

Liquid Jets ◽

Liquid Jet ◽

Moderate Reynolds Number ◽

Different Types ◽

Newtonian Liquids

We studied numerically impingement of vertical liquid jets of moderate Reynolds number for both Newtonian and non-Newtonian liquids to clarify the structure formation of circular hydraulic jump and the phenomenon of jet buckling. First, we have studied the hydraulic jump characteristics and governing parameters for a laminar water jet. Moreover, different types of hydraulic jump have been investigated by varying the height of a circular wall around the bed in flow downstream. The results show that a circular hydraulic jump has two kinds of steady states which can be reached by changing wall height. Next, we studied the impingement of a non-Newtonian liquid jet on a solid surface. In this case, we observe that instead of having a significant hydraulic jump, jet buckling phenomenon happens. The results were used in order to achieve a better understanding of the jet buckling phenomenon and the conditions in which this phenomenon happens.

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Impact of Newtonian Liquid Jets on Smooth and Patterned Solid Walls

Energy Procedia ◽

10.1016/j.egypro.2017.03.1081 ◽

2017 ◽

Vol 112 ◽

pp. 186-193 ◽

Cited By ~ 1

Author(s):

Iulia Rodica Damian ◽

Ioana Laura Omocea ◽

Diana Broboana ◽

Corneliu Balan

Keyword(s):

Newtonian Liquid ◽

Liquid Jets ◽

Solid Walls

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Self-focusing of thin liquid jets

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2007.0068 ◽

2007 ◽

Vol 464 (2089) ◽

pp. 197-206 ◽

Cited By ~ 4

Author(s):

Laurent Duchemin

Keyword(s):

Free Surface ◽

Time Evolution ◽

Scaling Laws ◽

Two Dimensions ◽

Three Dimensions ◽

Liquid Jets ◽

Self Similarity ◽

Long Time ◽

Self Similar ◽

Long Time Evolution

The nonlinear evolution of an initially perturbed free surface perpendicularly accelerated, or of an initially flat free surface subject to a perturbed velocity profile, gives rise to the emergence of thin spikes of fluid. We are investigating the long-time evolution of a thin inviscid jet of this kind, subject or not to a body force acting in the direction of the jet itself. A fully nonlinear theory for the long-time evolution of the jet is given. In two dimensions, the curvature of the tip scales like t 3 , where t is time, and the peak undergoes an overshoot in acceleration which evolves like t −5 . In three dimensions, the jet evolves towards an axisymmetric shape, and the curvature and the overshoot in acceleration obey asymptotic laws in t 2 and t −4 , respectively. The asymptotic self-similar shape of the spike is found to be a hyperbola in two dimensions, a hyperboloid in three dimensions. Scaling laws and self-similarity are confronted with two-dimensional computations of the Richtmyer–Meshkov instability.

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Effect of liquid elasticity on the behaviour of high-speed focused jets

Experiments in Fluids ◽

10.1007/s00348-020-03128-w ◽

2021 ◽

Vol 62 (2) ◽

Author(s):

A. Franco-Gómez ◽

H. Onuki ◽

Y. Yokoyama ◽

Y. Nagatsu ◽

Y. Tagawa

Keyword(s):

Inkjet Printing ◽

High Speed ◽

Xanthan Gum ◽

High Viscosity ◽

Newtonian Liquid ◽

Elastic Solution ◽

Rheological Parameters ◽

Liquid Jets ◽

Sodium Polyacrylate ◽

Speed Effect

AbstractWe investigate the effect of highly contrasting non-Newtonian liquid properties on the formation of liquid jets with a focused shape. By using two nozzle-free ejection techniques, mechanically impact- and laser-induced, fast jets of a highly elastic (sodium polyacrylate) and weakly elastic (xanthan-gum) diluted polymer solutions are generated. A unique high-speed effect is encountered at the jet ejection onset of the highly elastic solution. Its jet-tip speed is on average 1.4 times faster in comparison to a Newtonian (glycerin/water) and the weakly elastic liquids. We explain this effect occurring as a result of the high viscoelasticity of the sodium polyacrylate solution. Additionally, a ‘bungee jumper’ jet behaviour (Morrison and Harlen in Rheol Acta 49(6):619–632, 2010) is observed in a regime of high speed ($$10<V_j<40$$ 10 < V j < 40 m/s) and high viscosity ($$\mu >20$$ μ > 20 mPa s) not previously examined. We additionally characterise the viscoelastic non-breakup jet limit using the Bazilevskii et al. (Fluid Dyn 40(3):376–392, 2005) ejection criterion. Herein, the extensional rheological parameters are measured implementing a novel DoS-CaBER technique (Dinic et al. in Lab Chip 17(3):460–473, 2017). Our findings may influence results of inkjet printing technologies and recent nozzle-free ejection systems for ejecting liquids with non-Newtonian properties. Graphical abstract

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