Slow Dripping of Yield-Stress Fluids

2005 ◽  
Vol 127 (4) ◽  
pp. 687-690 ◽  
Author(s):  
M. A. M. Al Khatib ◽  
S. D. R. Wilson
Keyword(s):  
Coordinate System ◽  
Yield Stress ◽  
Special Interest ◽  
Vertical Tube ◽  
Viscoplastic Fluids ◽  
Yield Stress Fluids ◽  
Lagrangian Coordinate ◽  
Lagrangian Coordinate System

The dripping problem of a viscoplastic (yield-stress) liquid running slowly out of a narrow vertical tube is considered. The volume of the drops which break away is determined. A Lagrangian coordinate system is used to analyze the extension of the thread as it sags under its own weight, neglecting inertia and capillarity. The biviscosity model has been used to characterize viscoplastic fluids; the Newtonian and Bingham models can be recovered as limiting cases. The Bingham limit is of special interest.

The Stretching of a Viscoplastic Thread of Liquid

2003 ◽  
Vol 125 (6) ◽  
pp. 946-951 ◽  
Author(s):  
M. A. M. Al Khatib
Keyword(s):  
Coordinate System ◽  
Yield Stress ◽  
Special Interest ◽  
Inertial Effects ◽  
Viscoplastic Fluids ◽  
Lagrangian Coordinate ◽  
Lagrangian Coordinate System

The problem of stretching a viscoplastic (yield-stress) thread of a liquid hanging vertically is considered. The length of the thread at later times and the time at which it ruptures is determined. A Lagrangian coordinate system is used to analyze the extension of the thread as it sags under its own weight, with negligible inertial effects. The biviscosity model has been used to characterize viscoplastic fluids; the Newtonian and Bingham models can be recovered as limiting cases. The Bingham limit is of special interest.

scholarly journals A quasi-Lagrangian coordinate system based on high resolution tracer observations: implementation for the Antarctic polar vortex

2008 ◽  
Vol 8 (4) ◽  
pp. 16123-16173 ◽  
Author(s):  
E. V. Ivanova ◽  
C. M. Volk ◽  
O. Riediger ◽  
H. Klein ◽  
N. M. Sitnikov ◽  
...  
Keyword(s):  
High Resolution ◽  
Coordinate System ◽  
Vortex Core ◽  
Polar Vortex ◽  
Mixing Ratio ◽  
Lagrangian Coordinate ◽  
Antarctic Polar Vortex ◽  
The Antarctic ◽  
Lagrangian Coordinate System

Abstract. In order to quantitatively analyse the chemical and dynamical evolution of the polar vortex it has proven extremely useful to work with coordinate systems that follow the vortex flow. We propose here a two-dimensional quasi-Lagrangian coordinate system {χi, Δχi}, based on the mixing ratio of a long-lived stratospheric trace gas i, and its systematic use with i = N2O, in order to describe the structure of a well-developed Antarctic polar vortex. In the coordinate system {χi, Δχi} the mixing ratio χi is the vertical coordinate and Δχi = χi(Θ)−χivort(Θ) is the meridional coordinate (χivort(Θ) being a vertical reference profile in the vortex core). The quasi-Lagrangian coordinates {χi, Δχi} persist for much longer time than standard isentropic coordinates, potential temperature Θ and equivalent latitude φe, do not require explicit reference to geographic space, and can be derived directly from high-resolution in situ measurements. They are therefore well-suited for studying the evolution of the Antarctic polar vortex throughout the polar winter with respect to the relevant chemical and microphysical processes. By using the introduced coordinate system {χN2O, ΔχN2O} we analyze the well-developed Antarctic vortex investigated during the APE-GAIA (Airborne Polar Experiment – Geophysica Aircraft in Antarctica – 1999) campaign (Carli et al., 2000). A criterion, which uses the local in-situ measurements of χi=χi(Θ) and attributes the inner vortex edge to a rapid change (δ-step) in the meridional profile of the mixing ratio χi, is developed to determine the (Antarctic) inner vortex edge. In turn, we suggest that the outer vortex edge of a well-developed Antarctic vortex can be attributed to the position of a local minimum of the χH2O gradient in the polar vortex area. For a well-developed Antarctic vortex, the ΔχN2O-parametrization of tracer-tracer relationships allows to distinguish the tracer inter-relationships in the vortex core, vortex boundary region and surf zone and to examine their meridional variation throughout these regions. This is illustrated by analyzing the tracer-tracer relationships χi : χN2O obtained from the in-situ data of the APE-GAIA campaign for i = CFC-11, CFC-12, H-1211 and SF6. A number of solitary anomalous points in the CFC-11 : N2O correlation, observed in the Antarctic vortex core, are interpreted in terms of small-scale cross-isentropic dispersion.

scholarly journals The Lagrangian coordinate system and what it means for two-dimensional crowd flow models

2016 ◽  
Vol 443 ◽  
pp. 272-285 ◽  
Author(s):  
Femke van Wageningen-Kessels ◽  
Ludovic Leclercq ◽  
Winnie Daamen ◽  
Serge P. Hoogendoorn
Keyword(s):  
Coordinate System ◽  
Two Dimensional ◽  
Flow Models ◽  
Lagrangian Coordinate ◽  
Lagrangian Coordinate System

Multi-layer channel flows with yield stress fluids

2011 ◽  
Vol 166 (5-6) ◽  
pp. 262-278 ◽  
Author(s):  
S. Hormozi ◽  
K. Wielage-Burchard ◽  
I.A. Frigaard
Keyword(s):  
Yield Stress ◽  
Channel Flows ◽  
Yield Stress Fluids

A modern look on yield stress fluids

2016 ◽  
Vol 56 (3) ◽  
pp. 177-188 ◽  
Author(s):  
Alexander Malkin ◽  
Valery Kulichikhin ◽  
Sergey Ilyin
Keyword(s):  
Yield Stress ◽  
Yield Stress Fluids

Estimation of Rate of Strain Magnitude and Average Viscosity in Turbulent Flow of Shear Thinning and Yield Stress Fluids

2010 ◽  
Author(s):  
Robert Sawko ◽  
Chris P. Thompson ◽  
Theodore E. Simos ◽  
George Psihoyios ◽  
Ch. Tsitouras
Keyword(s):  
Turbulent Flow ◽  
Yield Stress ◽  
Shear Thinning ◽  
Yield Stress Fluids ◽  
Strain Magnitude

scholarly journals On the Determination of the Yield Surface within the Flow of Yield Stress Fluids using Computational Fluid Dynamics

2018 ◽  
Vol 11 (4) ◽  
pp. 971-982 ◽  
Author(s):  
N. Schaer ◽  
J. Vazquez ◽  
M. Dufresne ◽  
G. Isenmann ◽  
J. Wertel ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Yield Stress ◽  
Yield Surface ◽  
Yield Stress Fluids

The influence of thixotropy in start-up flow of yield stress fluids in a pipe

2018 ◽  
Vol 171 ◽  
pp. 794-807 ◽  
Author(s):  
G.V.L. Moisés ◽  
L.S. Alencar ◽  
M.F. Naccache ◽  
I.A. Frigaard
Keyword(s):  
Yield Stress ◽  
Yield Stress Fluids ◽  
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