Rimming flows with an axially varying viscosity

2004 ◽  
Vol 16 (3) ◽  
pp. 633-640 ◽  
Author(s):  
Bo Jin ◽  
Andreas Acrivos
Keyword(s):  
Varying Viscosity ◽  
Rimming Flows

FLOW-PRESSURE RELATIONS IN CALCIUM-SOAP–OIL SYSTEMS

1946 ◽  
Vol 24b (3) ◽  
pp. 73-80
Author(s):  
Wilfred Gallay ◽  
Ira E. Puddington
Keyword(s):  
Viscosity Index ◽  
Calcium Soap ◽  
Mineral Oils ◽  
Yield Value ◽  
Flow Pressure ◽  
Varying Viscosity

Flow–pressure relations have been determined for suspensions of calcium soaps in mineral oils of varying viscosity and viscosity index. The effect of small amounts of reagents on the character of these curves is very marked. The addition of water generally increases the yield value of the system without affecting the mobility, while solvents for calcium soaps tend to change the mobility without altering the yield value.

scholarly journals Steady rimming flows with surface tension

2008 ◽  
Vol 597 ◽  
pp. 91-118 ◽  
Author(s):  
E. S. BENILOV ◽  
M. S. BENILOV ◽  
N. KOPTEVA
Keyword(s):  
Thin Film ◽  
Surface Tension ◽  
Viscous Fluid ◽  
Small Parameter ◽  
Outer Region ◽  
Lubrication Approximation ◽  
Steady Flows ◽  
Matched Asymptotics ◽  
Weak Surface ◽  
Rimming Flows

We examine steady flows of a thin film of viscous fluid on the inside of a cylinder with horizontal axis, rotating about this axis. If the amount of fluid in the cylinder is sufficiently small, all of it is entrained by rotation and the film is distributed more or less evenly. For medium amounts, the fluid accumulates on the ‘rising’ side of the cylinder and, for large ones, pools at the cylinder's bottom. The paper examines rimming flows with a pool affected by weak surface tension. Using the lubrication approximation and the method of matched asymptotics, we find a solution describing the pool, the ‘outer’ region, and two transitional regions, one of which includes a variable (depending on the small parameter) number of asymptotic zones.

scholarly journals A numerical study for convection in a cylindrical model with continuously varying viscosity

1996 ◽  
Vol 39 (3) ◽  
Author(s):  
F. Fanucci ◽  
A. Megna ◽  
S. Santini ◽  
F. Vetrano
Keyword(s):  
Viscosity Solutions ◽  
Numerical Study ◽  
Viscosity Coefficient ◽  
Cylindrical Symmetry ◽  
The Earth ◽  
Realistic Representation ◽  
Convective Motions ◽  
Constant Viscosity ◽  
Varying Viscosity ◽  
Better Than

In the framework of a cylindrical symmetry model for convective motions in the asthenosphere, a new profile for the viscosity coefficient depending on depth is suggested here. The numerical elaboration of the above mentioned model leads to interesting results which fit well with experimental observations. In particular these continuously varying viscosity solutions probably describe the convective motions within the Earth better than simple constant viscosity solutions. Consequently the temperature values seem to be a realistic representation of the possible thermal behaviour in the upper mantle.

scholarly journals Homogeneous Gelation Leads to Nanowire Forests in the Transition Between Electrospray and Electrospinning

2020 ◽  
Author(s):  
Lin Lei ◽  
Shensheng Chen ◽  
Catherine Nachtigal ◽  
Tyler Moy ◽  
Xin Yong ◽  
...  
Keyword(s):  
Dissipative Particle Dynamics ◽  
Solution Temperature ◽  
Specific Viscosity ◽  
Critical Solution Temperature ◽  
Electrostatic Deposition ◽  
Low Viscosity ◽  
Gel Phase ◽  
Spatially Varying ◽  
Electrostatic Spray ◽  
Varying Viscosity

<p>The morphology of coatings created by electrostatic deposition can be generally divided into three categories: wire mats (electrospinning), particles (electrostatic spray, electrospray deposition(ESD)), and films (all low-viscosity applications). There should exist nanowire forests as a mixture of wire and particulate deposition. Such a morphology has yet to be observed experimentally, which we propose is the result of spatially-varying viscosity in sprayed droplets. We utilized electrostatic dissipative particle dynamics (DPD) and ESD to explore the spray of methylcellulose (MC) in water:ethanol mixtures. MC possesses a lower critical solution temperature (LCST) in water and water:ethanol blends. DPD simulations reveal that the barrier to forming nanowire forests is the directional nature of evaporation, but they should form were evaporation homogeneous. In ESD conducted above the LCST, MC and water phase separate concurrently with the rapid evaporation of ethanol, forming a homogeneous gel phase. This gel can undergo the elongation of electrospinning on a drop-by-drop basis to create forests of individual nanowires. Our study indicates that this homogenous evolution of viscosity is necessary for nanowire forest formation and that the specific viscosity (along with droplet size) further controls the morphology of the forests.</p>

The Onset of Whirl Instability in Journal Bearings of Various Bore Shapes and Groove Sizes

1983 ◽  
Vol 105 (3) ◽  
pp. 342-352 ◽  
Author(s):  
M. Akko¨k ◽  
C. M. McC. Ettles
Keyword(s):  
Beneficial Effect ◽  
Load Capacity ◽  
Journal Bearings ◽  
Experimental Results ◽  
General Validity ◽  
Model Based ◽  
Linearized Model ◽  
Varying Viscosity

Experimental results are given for load capacity and whirl onset in journal bearings of circular, elliptical and offset halves bore shape. The general validity of the linearized model for predicting whirl is confirmed experimentally. Deviations between experimental results and the model, based on an isoviscous film, are attributed to the varying viscosity that occurs in practice, and to unavoidable excitation that gives rise to premature whirl. It is shown that increasing groove size has a destabilizing effect that can more than cancel the beneficial effect of preloading. This result is particularly relevant to the design of journal bearings in turbomachinery.

The Sector-Shaped Pad

1956 ◽  
Vol 23 (4) ◽  
pp. 584-586
Author(s):  
C. F. Kettleborough
Keyword(s):  
Numerical Methods ◽  
Operating Characteristics ◽  
Simplifying Assumptions ◽  
Varying Viscosity

Abstract Boegli’s simplifying assumptions for the solution of the rectangular pad has been applied to the sector-shaped pad and extended to the case of varying viscosity. The process of obtaining the operating characteristics is very rapid and yields results comparable with those obtained by longer numerical methods.

On the stability of rimming flows to two-dimensional disturbances

2003 ◽  
Vol 33 (1-2) ◽  
pp. 141-172 ◽  
Author(s):  
M Villegas-Díaz ◽  
H Power ◽  
D S Riley
Keyword(s):  
Two Dimensional ◽  
The Stability ◽  
Rimming Flows
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