Effect of gap width on stability of non-Newtonian Taylor-Couette flow

2012 ◽  
Vol 92 (5) ◽  
pp. 393-408 ◽  
Author(s):  
N. Ashrafi ◽  
H. Karimi Haghighi
Keyword(s):  
Couette Flow ◽  
Taylor Couette ◽  
Gap Width ◽  
Taylor Couette Flow

Torque scaling in turbulent Taylor–Couette flow between independently rotating cylinders

2007 ◽  
Vol 581 ◽  
pp. 221-250 ◽  
Author(s):  
BRUNO ECKHARDT ◽  
SIEGFRIED GROSSMANN ◽  
DETLEF LOHSE
Keyword(s):  
Couette Flow ◽  
Power Law ◽  
Rotation Frequency ◽  
Strong Increase ◽  
Geometrical Factor ◽  
Driving Frequency ◽  
Taylor Couette ◽  
Rayleigh Benard ◽  
Gap Width ◽  
Taylor Couette Flow

Turbulent Taylor–Couette flow with arbitrary rotation frequencies ω1, ω2 of the two coaxial cylinders with radii r1 < r2 is analysed theoretically. The current Jω of the angular velocity ω(x,t) = uϕ(r,ϕ,z,t)/r across the cylinder gap and and the excess energy dissipation rate ϵw due to the turbulent, convective fluctuations (the ‘wind’) are derived and their dependence on the control parameters analysed. The very close correspondence of Taylor–Couette flow with thermal Rayleigh–Bénard convection is elaborated, using these basic quantities and the exact relations among them to calculate the torque as a function of the rotation frequencies and the radius ratio η = r1/r2 or the gap width d = r2 − r1 between the cylinders. A quantity σ corresponding to the Prandtl number in Rayleigh–Bénard flow can be introduced, $\sigma = ((1 + \eta)/2)/\sqrt{\etaacute;)^4$. In Taylor–Couette flow it characterizes the geometry, instead of material properties of the liquid as in Rayleigh–Bénard flow. The analogue of the Rayleigh number is the Taylor number, defined as Ta ∝ (ω1 − ω2)2 times a specific geometrical factor. The experimental data show no pure power law, but the exponent α of the torque versus the rotation frequency ω1 depends on the driving frequency ω1. An explanation for the physical origin of the ω1-dependence of the measured local power-law exponents α(ω1) is put forward. Also, the dependence of the torque on the gap width η is discussed and, in particular its strong increase for η → 1.

Spontaneous layering in stratified turbulent Taylor–Couette flow

2013 ◽  
Vol 721 ◽  
Author(s):  
R. L. F. Oglethorpe ◽  
C. P. Caulfield ◽  
Andrew W. Woods
Keyword(s):  
Couette Flow ◽  
Outer Cylinder ◽  
Buoyancy Frequency ◽  
Number Of Layers ◽  
Asymptotic Constant ◽  
Inner Radius ◽  
Velocity Scale ◽  
Taylor Couette ◽  
Gap Width ◽  
Taylor Couette Flow

AbstractWe conduct a series of laboratory experiments to study the mixing of an initially linear stratification in turbulent Taylor–Couette flow. We vary the inner radius, ${R}_{1} $, and rotation rate, $\Omega $, relative to the fixed outer cylinder, of radius ${R}_{2} $, as well as the initial buoyancy frequency ${N}_{0} = \sqrt{(- g/ \rho )\partial \rho / \partial z} $. We find that a linear stratification spontaneously splits into a series of layers and interfaces. The characteristic height of these layers is proportional to ${U}_{H} / {N}_{0} $, where ${U}_{H} = \sqrt{{R}_{1} { \mathrm{\Delta} }_{R} } \Omega $ is a horizontal velocity scale, with ${ \mathrm{\Delta} }_{R} = {R}_{2} - {R}_{1} $ the gap width of the annulus. The buoyancy flux through these layers matches the equivalent flux through a two-layer stratification, independently of the height or number of layers. For a strongly stratified flow, the flux tends to an asymptotic constant value, even when multiple layers are present, consistent with Woods et al. (J. Fluid Mech., vol. 663, 2010, pp. 347–357). For smaller stratification the flux increases, reaching a maximum just before the layers disappear due to overturning of the interfaces.

scholarly journals Catastrophic Phase Inversion in High-Reynolds-Number Turbulent Taylor-Couette Flow

2021 ◽  
Vol 126 (6) ◽  
Author(s):  
Dennis Bakhuis ◽  
Rodrigo Ezeta ◽  
Pim A. Bullee ◽  
Alvaro Marin ◽  
Detlef Lohse ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Couette Flow ◽  
Phase Inversion ◽  
High Reynolds Number ◽  
Taylor Couette ◽  
High Reynolds ◽  
Taylor Couette Flow

scholarly journals Effect of roll number on the statistics of turbulent Taylor-Couette flow

2016 ◽  
Vol 1 (5) ◽  
Author(s):  
Rodolfo Ostilla-Mónico ◽  
Detlef Lohse ◽  
Roberto Verzicco
Keyword(s):  
Couette Flow ◽  
Taylor Couette ◽  
Taylor Couette Flow

scholarly journals Hydrodynamic synthesis of Fe2O3@MoS2 0D/2D-nanocomposite material and its application as a catalyst in the glycolysis of polyethylene terephthalate

RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 16841-16848
Author(s):  
Younghyun Cha ◽  
Yong-Ju Park ◽  
Do Hyun Kim
Keyword(s):  
Aqueous Solution ◽  
Couette Flow ◽  
Polyethylene Terephthalate ◽  
Flow Reactor ◽  
Nanocomposite Material ◽  
Taylor Couette ◽  
Taylor Couette Flow

Fe2O3@MoS2 0D/2D-nanocomposite material was synthesized in an aqueous solution using a Taylor–Couette flow reactor.

A purely elastic transition in Taylor-Couette flow

1989 ◽  
Vol 28 (6) ◽  
pp. 499-503 ◽  
Author(s):  
S. J. Muller ◽  
R. G. Larson ◽  
E. S. G. Shaqfeh
Keyword(s):  
Couette Flow ◽  
Taylor Couette ◽  
Taylor Couette Flow
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