scholarly journals Breaking up of a drop of viscous liquid immersed in another viscous fluid which is extending at a uniform rate

1936 ◽  
Vol 153 (879) ◽  
pp. 302-318 ◽  
Keyword(s):  
Viscous Fluid ◽  
Viscous Liquid ◽  
Experimental Studies ◽  
Lubricating Oil ◽  
Disruptive Effect ◽  
Viscous Forces ◽  
Two Fluids ◽  
Initial Drop ◽  
Break Up ◽  
Surrounding Liquid

1—In a previous papers the present writer has discussed the instability of a long cylindrical column of an incompressible viscous liquid surrounded by another viscous fluid under the action of both surface tension and viscous forces. In this work the fluids were at rest except for the small disturbances which were assumed to develop slowly. It was shown that if the ratio of viscosities of the two fluids is neither zero nor infinity the maximum instability always occurs at a certain definite value of the wavelength of the assumed initial varicosity so that the formation of drops of definite size would be expected. A comparison of the theory with observation has also been made and satisfactorily good agreement between them was found. Now, in his experimental studies on the mode of formation of a cylindrical thread from a drop of a viscous liquid by the disruptive effect of the viscous drags of a surrounding liquid, professor G. I. Taylor observed that when a drop of black lubricating oil was surrounded by syrup, the thread formed by pulling out the drop did not at once break up into small drops but remained cylindrical for some time and finally broke up into small drops, the diameters of which were about 1/10th of the diameter of the original drop. On the other band, if as soon as the cylindrical thread was formed the apparatus was stopped the thread immediately began to break up in the manner described above. Thus, if the apparatus were kept going very much smaller drops were formed than if it were stopped as soon as the initial drop bad been pulled out into a cylindrical thread.

scholarly journals On the instability of a cylindrical thread of a viscous liquid surrounded by another viscous fluid

1935 ◽  
Vol 150 (870) ◽  
pp. 322-337 ◽  
Keyword(s):  
Viscous Fluid ◽  
Viscous Liquid ◽  
Wave Length ◽  
Dynamical Theory ◽  
Viscous Drag ◽  
Disruptive Effect ◽  
Interesting Phenomenon ◽  
Viscous Forces ◽  
Cylindrical Column ◽  
Surrounding Fluid

1—The dynamical theory of the instability of a long cylindrical column of an incompressible perfect liquid under the action of capillary force has been given by Rayleigh, neglecting the effect of the surrounding fluid. According to his results, if the column becomes varicose with wave-length λ , the equilibrium of the column is unstable, provided λ exceed the circumference 2π a of the cylinder, in accordance with the result of Plateau’s statical theory; and the degree of instability, as indicated by the value of q in the exponential e qt to which the motion is assumed to be proportional, depends upon the value of λ reaching a maximum when λ = 4.51 × 2 a . The case of a long cylindrical column of an incompressible viscous liquid has also been discussed by Rayleigh, again leaving out of consideration the effect of the surrounding fluid. Assuming the viscosity to be very great compared with the inertia and neglecting the effect of the latter, he has shown that for a very viscous liquid column the maximum instability occurs when the wave-length of the varicosity is very large in comparison with the radius of the cylinder, i. e ., when λ = ∞ theoretically. Quite recently G. I. Taylor has made interesting experimental researches, together with some theoretical investigations, upon the mode of formation of the cylindrical thread by the disruptive effect of the viscous drag of one fluid on the other, by putting a small drop of a viscous liquid in definable shearing fields of flow of another viscous liquid. He has thus thrown much light upon the mechanism of the formation of emulsions. In the course of his experiments he observed an interesting phenomenon, in one case when the ratio of the viscosity of the liquid forming the thread to that of the surrounding liquid is 0.91, that after the apparatus which was used to produce the field of flow was stopped the final thread gradually broke up into a number of small drops spaced at nearly regular intervals, although it had seemed quite stable while the apparatus was in motion. In connection with this interesting phenomenon, Professor G. I. Taylor kindly suggested to the writer a problem of investigating the character of the equilibrium of a long cylindrical thread of a viscous liquid surrounded by an­other viscous fluid under the action of interfacial surface tension as well as under the effect of viscous forces acting on the liquid inside the column by the surrounding viscous fluid. The effect of the latter is expected to play some important role in the phenomenon under con­sideration, although, as mentioned already, its effect had been neglected by Rayleigh in his investigation.

scholarly journals The formation of emulsions in definable fields of flow

1934 ◽  
Vol 146 (858) ◽  
pp. 501-523 ◽  
Keyword(s):  
Surface Tension ◽  
The Other ◽  
Viscous Drag ◽  
Disruptive Effect ◽  
Spherical Drop ◽  
Viscous Forces ◽  
Two Fluids ◽  
Pure Rotation ◽  
Physical And Chemical ◽  
Er Fluid

The physical and chemical condition of emulsions of two fluids which do not mix has been the subject of many studies, but very little seems to be known about the mechanics of the stirring processes which are used in making them. The conditions which govern the breaking up of a jet of one fluid projected into another have been studied by Rayleigh and others, but most of these studies have been concerned with the effect of surface tension or dynamical forces in making a cylindrical thread unstable so that it breaks into drops. The mode of formation of the cylindrical thread has not been discussed. As a rule in experimental work it has been formed by projecting one liquid into the other under pressure through a hole. It seems that studies of this kind which neglect the disruptive effect of the viscous drag of one fluid on the other, though interesting in themselves, tell us very little about the manner in which two liquids can be stirred together to form an emulsion. When one liquid is at rest in another liquid of the same density it assumes the form of a spherical drop. Any movement of the out er fluid (apart from pure rotation or translation) will distort the drop owing to the dynamical and viscous forces which then act on its surface. Surface tension, however, will tend to keep the drop spherical. When the drop is very small, or the liquid very viscous, the stresses due to inertia will be small compared with those due to viscosity.

Reflection of a longitudinal travelling wave from the notch in a rod plunged into viscous liquid

2010 ◽  
Vol 7 ◽  
pp. 129-142
Author(s):  
M.A. Ilgamov ◽  
A.G. Khakimov
Keyword(s):  
Inverse Problem ◽  
Viscous Liquid ◽  
Travelling Wave ◽  
Observation Point ◽  
Reflected Waves ◽  
Damping Characteristics ◽  
Deformed State ◽  
Using Data ◽  
Surrounding Liquid

The article investigates the reflection of a longitudinal damped travelling wave from the transverse notch and its movement along an infinite rod plunged into viscous liquid. The simplest model for the stress deformed state in the notch zone is applied. The solution is found to depend on the parameters of the liquid and damping characteristics in the material of the rod and the surrounding liquid. The solution to the inverse problem makes it possible to define the coordinate of the notch and the parameter that contains its depth and length using data on both the incident and reflected waves at the observation point.

Slender-body theory for steady sheared plumes in very viscous fluid

2008 ◽  
Vol 612 ◽  
pp. 21-44 ◽  
Author(s):  
ROBERT J. WHITTAKER ◽  
JOHN R. LISTER
Keyword(s):  
Simple Model ◽  
Shear Flow ◽  
Viscous Fluid ◽  
Experimental Studies ◽  
Slender Body ◽  
Slender Body Theory ◽  
Dimensionless Parameters ◽  
Dynamical Regimes ◽  
Body Theory ◽  
Good Agreement

A simple model based on slender-body theory is developed to describe the deflection of a steady plume by shear flow in very viscous fluid of the same viscosity. The key dimensionless parameters measuring the relative strengths of the shear, diffusion and source flux are identified, which allows a number of different dynamical regimes to be distinguished. The predictions of the model show good agreement with many, but not all, observations from previous experimental studies. Possible reasons for the discrepancies are discussed.

Effect of hexagonal boron nitride nanoparticles as an additive on the extreme pressure properties of engine oil

2016 ◽  
Vol 68 (4) ◽  
pp. 441-445 ◽  
Author(s):  
Muhammad Ilman Hakimi Chua Abdullah ◽  
Mohd Fadzli Bin Abdollah ◽  
Noreffendy Tamaldin ◽  
Hilmi Amiruddin ◽  
Nur Rashid Mat Nuri
Keyword(s):  
Diesel Engine ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Experimental Studies ◽  
Engine Oil ◽  
Lubricating Oil ◽  
Extreme Pressure ◽  
Content Type ◽  
Load Carrying ◽  
Sonication Technique

Purpose This paper aims to investigate the effect of hexagonal boron nitride (hBN) nanoparticles on extreme pressure (EP) properties when used as an additive in lubricating oil. Design/methodology/approach The nano-oil was prepared by dispersing an optimal composition of 0.5 vol. per cent of 70 nm hBN in SAE 15W-40 diesel engine oil using a sonication technique. The tribological testing was performed using a four-ball tribometer according to the ASTM standard. Findings It was found that the nano-oil has a potential to decelerate the seizure point on the contact surfaces, where higher EP can be obtained. More adhesive wear was observed on the worn surfaces of ball bearing lubricated with SAE 15W-40 diesel engine oil as compared with the nano-oil lubrication. Originality/value The results of the experimental studies demonstrated the potential of hBN as an additive for improving the load-carrying ability of lubricating oil.

scholarly journals Formation and Break-up of Pendant Drops in a Viscous Liquid

2017 ◽  
Vol 112 ◽  
pp. 204-209
Author(s):  
Ioana Laura Omocea ◽  
Iulia - Rodica Damian ◽  
Claudiu Patrascu ◽  
Corneliu Balan
Keyword(s):  
Viscous Liquid ◽  
Break Up ◽  
Pendant Drops

scholarly journals Encapsulation of Droplets Using Cusp Formation behind a Drop Rising in a Non-Newtonian Fluid

Fluids ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 54 ◽  
Author(s):  
Raphaël Poryles ◽  
Roberto Zenit
Keyword(s):  
Critical Velocity ◽  
Newtonian Fluid ◽  
Formation Process ◽  
Critical Size ◽  
Long Tail ◽  
Capillary Effects ◽  
Velocity Discontinuity ◽  
Two Fluids ◽  
Viscous Solution ◽  
Surrounding Liquid

The rising of a Newtonian oil drop in a non-Newtonian viscous solution is studied experimentally. In this case, the shape of the ascending drop is strongly affected by the viscoelastic and shear-thinning properties of the surrounding liquid. We found that the so-called velocity discontinuity phenomena is observed for drops larger than a certain critical size. Beyond the critical velocity, the formation of a long tail is observed, from which small droplets are continuously emitted. We determined that the fragmentation of the tail results mainly from the effect of capillary effects. We explore the idea of using this configuration as a new encapsulation technique, where the size and frequency of droplets are directly related to the volume of the main rising drop, for the particular pair of fluids used. These experimental results could lead to other investigations, which could help to predict the droplet formation process by tuning the two fluids’ properties, and adjusting only the volume of the main drop.

Primary Break-up of a Viscous Liquid Jet in a Cross Airflow

2003 ◽  
Vol 20 (4) ◽  
pp. 283-289 ◽  
Author(s):  
Madjid Birouk ◽  
Barry J. Azzopardi ◽  
Thomas Stäbler
Keyword(s):  
Viscous Liquid ◽  
Liquid Jet ◽  
Break Up ◽  
Primary Break

Interacting cosmological viscous fluid with Little Rip and Pseudo Rip solutions in f(R) gravity

2018 ◽  
Vol 15 (02) ◽  
pp. 1850028 ◽  
Author(s):  
R. D. Boko ◽  
M. J. S. Houndjo ◽  
J. Tossa
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Equation Of State ◽  
Viscous Fluid ◽  
Modified Gravity ◽  
Infinite Time ◽  
Two Fluids ◽  
Viscosity Models ◽  
Time Singularities ◽  
Analytic Expressions

In this paper, we investigate the evolution of the equation of state of the interacting viscous dark energy in [Formula: see text] gravity. We first consider the case when the dark energy does not interact with the dark matter and after, the case where there is a coupling between these dark components. The viscosity and the interaction between the two fluids are parameterized by constants [Formula: see text] and [Formula: see text] respectively for which a detailed investigation on the cosmological implications has been done. In the later part of the paper, we explore some bulk viscosity models with Little and Pseudo Rip infinite time singularities within [Formula: see text] modified gravity. We obtain analytic expressions for characteristic properties of these cosmological models.

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