Nucleation and Growth of Liquid Droplets Under a Shear Flow

1991 ◽  
Vol 248 ◽  
Author(s):  
F. Perrot ◽  
T. Baumberger
Keyword(s):  
Shear Flow ◽  
Volume Fraction ◽  
Liquid Droplets ◽  
Subsequent Growth ◽  
Two Phase ◽  
Angle Scattering ◽  
Steady Shear Flow ◽  
Mixture Volume ◽  
New Phase

AbstractPhase separation in an off-critical binary mixture is studied under an uniform and steady shear flow. The nucleation and subsequent growth of droplets in aweakly supersaturated mixture (volume fraction of the new phase smaller than 10%) is studied by small angle scattering and turbidity measurements. The completion of the nucleation process is shown to be accelerated by the shear flow. At very low supersaturation, a strong effect of shear is detected which can be related to shear-triggered nucleation. In situ measurements ’of the surface tension between the two phase-separating phases obtained by studying the deformation and tilt of the growing droplets is discussed.

scholarly journals In Situ Dielectric Characterization of Poly(ethylene oxide) Melts Containing Lithium Perchlorate under Steady Shear Flow

2004 ◽  
Vol 37 (18) ◽  
pp. 7064-7064
Author(s):  
Yumi Matsumiya ◽  
Nitash P. Balsara ◽  
John B. Kerr ◽  
Tadashi Inoue ◽  
Hiroshi Watanabe
Keyword(s):  
Shear Flow ◽  
Ethylene Oxide ◽  
Lithium Perchlorate ◽  
Dielectric Characterization ◽  
Steady Shear Flow ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Oxide Melts

scholarly journals Collisions of Two-Phase Liquid Droplets in a Heated Gas Medium

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1476
Author(s):  
Pavel Tkachenko ◽  
Nikita Shlegel ◽  
Pavel Strizhak
Keyword(s):  
Volume Fraction ◽  
Industrial Applications ◽  
Droplet Breakup ◽  
Liquid Volume ◽  
Liquid Droplets ◽  
Vapor Bubbles ◽  
Two Phase ◽  
Relative Volume Fraction ◽  
Phase Liquid ◽  
Gas Medium

The paper presents the experimental research findings for the integral characteristics of processes developing when two-phase liquid droplets collide in a heated gas medium. The experiments were conducted in a closed heat exchange chamber space filled with air. The gas medium was heated to 400–500 °C by an induction system. In the experiments, the size of initial droplets, their velocities and impact angles were varied in the ranges typical of industrial applications. The main varied parameter was the percentage of vapor (volume of bubbles) in the droplet (up to 90% of the liquid volume). The droplet collision regimes (coalescence, bounce, breakup, disruption), size and number of secondary fragments, as well as the relative volume fraction of vapor bubbles in them were recorded. Differences in the collision regimes and in the distribution of secondary fragments by size were identified. The areas of liquid surface before and after the initial droplet breakup were determined. Conditions were outlined in which vapor bubbles had a significant and, on the contrary, fairly weak effect on the interaction regimes of two-phase droplets.

ON THE EXTENDED RUTGERS–DELAWARE RULE FOR MR SUSPENSIONS UNDER MAGNETIC FIELDS

2006 ◽  
Vol 20 (05) ◽  
pp. 579-592 ◽  
Author(s):  
Y. B. YANG ◽  
G. CHEN ◽  
L. LI ◽  
W. H. LI
Keyword(s):  
Magnetic Fields ◽  
Shear Flow ◽  
Magnetic Particles ◽  
Volume Fraction ◽  
Complex Viscosity ◽  
Shift Factor ◽  
Oscillatory Shear ◽  
Oscillatory Shear Flow ◽  
Steady Shear Flow ◽  
Series Of Experiments

The interrelation between apparent viscosity in steady shear flow and complex viscosity in oscillatory shear flow for magnetorheological (MR) suspensions is investigated. Series of experiments have been conducted using a MR rheometer. An extended Rutgers–Delaware rule is proposed, in which an effective shear rate for oscillatory shear flow is defined as ωΔh. Here ωΔh is the shift factor dependent on strain amplitude (γ0), which was found to be similar for different MR suspensions under different magnetic fields. At high strain amplitudes (γ0≥100%), Δh≈γ0, the Rutgers–Delaware rule is approximately obeyed. At low strain amplitudes (γ0<100%), the curves of Δh fall between the line of the Cox–Merz rule and that of the Rutgers–Delaware rule. The curve of Δh at low strain amplitudes depends on the ingredients of the MR suspension. For samples with the same ingredients, a unified curve of Δh can be identified in a range of magnetic fields and/or for a range of volume fraction of magnetic particles.

scholarly journals Rheology of mobile sediment beds in laminar shear flow: effects of creep and polydispersity

2021 ◽  
Vol 932 ◽  
Author(s):  
Christoph Rettinger ◽  
Sebastian Eibl ◽  
Ulrich Rüde ◽  
Bernhard Vowinckel
Keyword(s):  
Friction Coefficient ◽  
Shear Flow ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Rheological Behaviour ◽  
Spherical Particles ◽  
Particle Volume ◽  
Two Phase ◽  
Transport Modelling ◽  
Static State

Classical scaling relationships for rheological quantities such as the $\mu (J)$ -rheology have become increasingly popular for closures of two-phase flow modelling. However, these frameworks have been derived for monodisperse particles. We aim to extend these considerations to sediment transport modelling by using a more realistic sediment composition. We investigate the rheological behaviour of sheared sediment beds composed of polydisperse spherical particles in a laminar Couette-type shear flow. The sediment beds consist of particles with a diameter size ratio of up to 10, which corresponds to grains ranging from fine to coarse sand. The data was generated using fully coupled, grain resolved direct numerical simulations using a combined lattice Boltzmann–discrete element method. These highly resolved data yield detailed depth-resolved profiles of the relevant physical quantities that determine the rheology, i.e. the local shear rate of the fluid, particle volume fraction, total shear and granular pressure. A comparison against experimental data shows excellent agreement for the monodisperse case. We improve upon the parameterization of the $\mu (J)$ -rheology by expressing its empirically derived parameters as a function of the maximum particle volume fraction. Furthermore, we extend these considerations by exploring the creeping regime for viscous numbers much lower than used by previous studies to calibrate these correlations. Considering the low viscous numbers of our data, we found that the friction coefficient governing the quasi-static state in the creeping regime tends to a finite value for vanishing shear, which decreases the critical friction coefficient by a factor of three for all cases investigated.

A new method for evaluating the size of plate-like precipitates by small-angle scattering

2012 ◽  
Vol 45 (6) ◽  
pp. 1208-1218 ◽  
Author(s):  
Frédéric De Geuser ◽  
Françoise Bley ◽  
Alexis Deschamps
Keyword(s):  
Small Angle ◽  
Volume Fraction ◽  
Small Angle Scattering ◽  
Number Density ◽  
X Ray ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Ewald Sphere ◽  
Scattering Study

A methodology is presented for extracting the thickness and length of plate-like precipitates from streaking that appears in the small-angle scattering pattern of moderately textured polycrystalline samples. This methodology builds upon existing work on single crystals but is extended to polycrystals through a modeling of the streaking misalignment distribution. It is also shown that it is essential to take into account the Ewald sphere curvature. The protocol is applied to anin situsmall-angle X-ray scattering study of the transition between θ′ andT1in an Al–Li–Cu system, where the contributions of both phases are well separated, and the size, volume fraction and number density are monitored.

Microstructures and Mechanical Behavior of Two-Phase Niobium Silicide-Niobium Alloys

1988 ◽  
Vol 133 ◽  
Author(s):  
M. G. Mendiratta ◽  
D. M. Dimiduk
Keyword(s):  
Mechanical Behavior ◽  
Phase Transformations ◽  
Room Temperature ◽  
Volume Fraction ◽  
Two Phase ◽  
Niobium Alloys ◽  
Intermetallic Matrix ◽  
Two Phases ◽  
The Individual

ABSTRACTIn the Nb-Si system, it is possible to produce in-situ composites consisting of a brittle Nb5Si3 intermetallic matrix and ductile Nb particles. The two phases are thermochemically stable up to ∼ 1500∼C and are amenable to wide microstructural variations including morphology, volume fraction, and the size of the individual microconstituents. This paper presents microstructures and phase transformations in these composites as a function of composition and heat treatments and bend properties from room-temperature to 1400°C.

In Situ Dielectric Characterization of Poly(ethylene oxide) Melts Containing Lithium Perchlorate under Steady Shear Flow

2004 ◽  
Vol 37 (2) ◽  
pp. 544-553 ◽  
Author(s):  
Yumi Matsumiya ◽  
Nitash P. Balsara ◽  
John B. Kerr ◽  
Tadashi Inoue ◽  
Hiroshi Watanabe
Keyword(s):  
Shear Flow ◽  
Ethylene Oxide ◽  
Lithium Perchlorate ◽  
Dielectric Characterization ◽  
Steady Shear Flow ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Oxide Melts
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