The Characteristic Length of a Polar Fluid

1968 ◽  
pp. 90-94
Author(s):  
S. C. Cowin
Keyword(s):  
Characteristic Length ◽  
Polar Fluid

Identification of the characteristic length scale for fatigue cracking in fretting contacts

1998 ◽  
Vol 08 (PR8) ◽  
pp. Pr8-159-Pr8-166 ◽  
Author(s):  
S. Fouvry ◽  
Ph. Kapsa ◽  
F. Sidoroff ◽  
L. Vincent
Keyword(s):  
Characteristic Length ◽  
Fatigue Cracking ◽  
Length Scale ◽  
Characteristic Length Scale

Magnetohydrodynamic flow of a polar fluid through a porous medium

1983 ◽  
Vol 69 (1) ◽  
pp. 530-534
Author(s):  
A. Raptis
Keyword(s):  
Porous Medium ◽  
Magnetohydrodynamic Flow ◽  
Polar Fluid

scholarly journals Lettau’s Contribution to the Obukhov Length Scale: A Scientific Historical Study

2021 ◽  
Author(s):  
Thomas Foken ◽  
Michael Börngen
Keyword(s):  
Characteristic Length ◽  
Stability Parameter ◽  
Historical Study ◽  
Length Scale ◽  
Characteristic Length Scale ◽  
Obukhov Length ◽  
The Future

AbstractIt has been repeatedly assumed that Heinz Lettau found the Obukhov length in 1949 independently of Obukhov in 1946. However, it was not the characteristic length scale, the Obukhov length L, but the ratio of height and the Obukhov length (z/L), the Obukhov stability parameter, that he analyzed. Whether Lettau described the parameter z/L independently of Obukhov is investigated herein. Regardless of speculation about this, the significant contributions made by Lettau in the application of z/L merit this term being called the Obukhov–Lettau stability parameter in the future.

scholarly journals Rotational Particle Separation in Solutions: Micropolar Fluid Theory Approach

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1072
Author(s):  
Vladimir Shelukhin
Keyword(s):  
Mathematical Model ◽  
Rotational Diffusion ◽  
Particle Separation ◽  
Theory Approach ◽  
Steady Flows ◽  
Concentric Cylinder ◽  
Polar Fluid ◽  
Fluid Theory ◽  
Couette Cell ◽  
Granular Fluid

We develop a new mathematical model for rotational sedimentation of particles for steady flows of a viscoplastic granular fluid in a concentric-cylinder Couette geometry when rotation of the Couette cell inner cylinder is prescribed. We treat the suspension as a micro-polar fluid. The model is validated by comparison with known data of measurement. Within the proposed theory, we prove that sedimentation occurs due to particles’ rotation and rotational diffusion.

On the dielectric constant for a non-polar fluid, a comparison

1977 ◽  
Vol 87 (2) ◽  
pp. 288-301 ◽  
Author(s):  
J.S. Høye ◽  
D. Bedeaux
Keyword(s):  
Dielectric Constant ◽  
Polar Fluid

scholarly journals A characteristic length scale causes anomalous size effects and boundary programmability in mechanical metamaterials

2017 ◽  
Vol 14 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Corentin Coulais ◽  
Chris Kettenis ◽  
Martin van Hecke
Keyword(s):  
Size Effects ◽  
Characteristic Length ◽  
Length Scale ◽  
Characteristic Length Scale ◽  
Mechanical Metamaterials

scholarly journals Simulation of MASPn Experiments in MISTRA Test Facility with COCOSYS Code

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Mantas Povilaitis ◽  
Egidijus Urbonavičius
Keyword(s):  
Boundary Conditions ◽  
Nuclear Power ◽  
Power Plants ◽  
Volume Fraction ◽  
Characteristic Length ◽  
Initial Conditions ◽  
Test Facility ◽  
Work Package ◽  
Acceptable Agreement

An issue of the stratified atmospheres in the containments of nuclear power plants is still unresolved; different experiments are performed in the test facilities like TOSQAN and MISTRA. MASPn experiments belong to the spray benchmark, initiated in the containment atmosphere mixing work package of the SARNET network. The benchmark consisted of MASP0, MASP1 and MASP2 experiments. Only the measured depressurisation rates during MASPn were available for the comparison with calculations. When the analysis was performed, the boundary conditions were not clearly defined therefore most of the attention was concentrated on MASP0 simulation in order to develop the nodalisation scheme and define the initial and boundary conditions. After achieving acceptable agreement with measured depressurisation rate, simulations of MASP1 and MASP2 experiments were performed to check the influence of sprays. The paper presents developed nodalisation scheme of MISTRA for the COCOSYS code and the results of analyses. In the performed analyses, several parameters were considered: initial conditions, loss coefficient of the junctions, initial gradients of temperature and steam volume fraction, and characteristic length of structures. Parametric analysis shows that in the simulation the heat losses through the external walls behind the lower condenser installed in the MISTRA facility determine the long-term depressurisation rate.

scholarly journals Gold Nanoparticles as a Photothermal Agent in Cancer Therapy: The Thermal Ablation Characteristic Length

Molecules ◽  
2018 ◽  
Vol 23 (6) ◽  
pp. 1316 ◽  
Author(s):  
Thomas Grosges ◽  
Dominique Barchiesi
Keyword(s):  
Gold Nanoparticles ◽  
Cancer Therapy ◽  
Thermal Ablation ◽  
Characteristic Length

Electroviscous forces on a charged particle suspended in a flowing liquid

1997 ◽  
Vol 338 ◽  
pp. 1-34 ◽  
Author(s):  
R. G. COX
Keyword(s):  
Particle Size ◽  
Physical Mechanism ◽  
Aqueous Electrolyte ◽  
Complete Agreement ◽  
Dominant Contribution ◽  
General Shape ◽  
Flowing Liquid ◽  
Polar Fluid ◽  
Double Layer Thickness ◽  
Made In

The force on a charged solid particle (of general shape) suspended in a flowing polar fluid (e.g. an aqueous electrolyte solution) in the presence of a solid bounding wall (of general shape) is obtained for the situation in which the electrical double-layer thickness is very much smaller than the particle size (and the distance between particle and wall). The very general results so obtained are applied to the sedimentation of a charged spherical particle in an unbounded polar fluid (with no walls present) for which the drag force is found to be in complete agreement with Ohshima et al. (1984). However, there is disagreement between the present results and those obtained in a number of published papers owing to incorrect assumptions being made in the latter as to what physical mechanism gives rise to the dominant contribution to the electroviscous force on the particle.

The extent of relaxation of weld residual stresses on cutting out cross-weld test-pieces

2009 ◽  
Vol 24 (S1) ◽  
pp. S31-S36 ◽  
Author(s):  
J. Altenkirch ◽  
A. Steuwer ◽  
M. J. Peel ◽  
P. J. Withers
Keyword(s):  
Thin Plate ◽  
Mechanical Performance ◽  
Characteristic Length ◽  
Weld Line ◽  
Proper Understanding ◽  
Test Pieces ◽  
Weld Residual Stress ◽  
Cutting Out ◽  
Empirical Curve ◽  
Lateral Width

Weld residual stress (RS) measurements are often undertaken on test-pieces which have been cut out from large components, yet it remains unclear to what extent the RSs in test-pieces are representative of those present in the original component. Similarly weld mechanical performance tests are frequently undertaken on cross-weld test-pieces without a proper understanding of the level or influence of retained RS. We present a systematic study of the relaxation of longitudinal RS in thin-plate butt welds produced using different materials and welding methods (FSW, laser-MIG, and pulsed-MIG). In each case the RSs were measured repeatedly in the same location as the welds were progressively and symmetrically cut down. Although cutting inevitably leads to stress redistribution, significant relaxation of the longitudinal RS was only observed when the weld length or width was reduced to below a certain value. This critical value appears to correlate with the lateral width of the tensile zone local to the weld-line and may be considered to be the characteristic length as defined in St. Venant’s principle. Further, it was found that the level of stress relaxation as a function of weld length for all the welds studied could be collapsed onto a single empirical curve using a simple approach based on the characteristic length scales of the weld. Given the range of materials and welding methods used, this relation appears to be of general use for thin-plate welds although further work is required to test the limits of its applicability.

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