scholarly journals Flow Velocity Profiles and Shear Banding Onset in a Semidilute Wormlike Micellar System under Couette Flow

2009 ◽  
Vol 113 (47) ◽  
pp. 15485-15494 ◽  
Author(s):  
Jorge Delgado ◽  
Hartmut Kriegs ◽  
Rolando Castillo
Keyword(s):  
Flow Velocity ◽  
Couette Flow ◽  
Shear Banding ◽  
Velocity Profiles ◽  
Micellar System

scholarly journals Azimuthal velocity profiles in Rayleigh-stable Taylor–Couette flow and implied axial angular momentum transport

2015 ◽  
Vol 774 ◽  
pp. 342-362 ◽  
Author(s):  
Freja Nordsiek ◽  
Sander G. Huisman ◽  
Roeland C. A. van der Veen ◽  
Chao Sun ◽  
Detlef Lohse ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Couette Flow ◽  
Outer Cylinder ◽  
Azimuthal Velocity ◽  
Velocity Profiles ◽  
Body Rotation ◽  
Solid Body Rotation ◽  
Angular Momentum Transport ◽  
Taylor Couette ◽  
Taylor Couette Flow

We present azimuthal velocity profiles measured in a Taylor–Couette apparatus, which has been used as a model of stellar and planetary accretion disks. The apparatus has a cylinder radius ratio of ${\it\eta}=0.716$, an aspect ratio of ${\it\Gamma}=11.74$, and the plates closing the cylinders in the axial direction are attached to the outer cylinder. We investigate angular momentum transport and Ekman pumping in the Rayleigh-stable regime. This regime is linearly stable and is characterized by radially increasing specific angular momentum. We present several Rayleigh-stable profiles for shear Reynolds numbers $\mathit{Re}_{S}\sim O(10^{5})$, for both ${\it\Omega}_{i}>{\it\Omega}_{o}>0$ (quasi-Keplerian regime) and ${\it\Omega}_{o}>{\it\Omega}_{i}>0$ (sub-rotating regime), where ${\it\Omega}_{i,o}$ is the inner/outer cylinder rotation rate. None of the velocity profiles match the non-vortical laminar Taylor–Couette profile. The deviation from that profile increases as solid-body rotation is approached at fixed $\mathit{Re}_{S}$. Flow super-rotation, an angular velocity greater than those of both cylinders, is observed in the sub-rotating regime. The velocity profiles give lower bounds for the torques required to rotate the inner cylinder that are larger than the torques for the case of laminar Taylor–Couette flow. The quasi-Keplerian profiles are composed of a well-mixed inner region, having approximately constant angular momentum, connected to an outer region in solid-body rotation with the outer cylinder and attached axial boundaries. These regions suggest that the angular momentum is transported axially to the axial boundaries. Therefore, Taylor–Couette flow with closing plates attached to the outer cylinder is an imperfect model for accretion disk flows, especially with regard to their stability.

scholarly journals Three-Dimensional Visualization of Pulmonary Blood Flow Velocity Profiles in Lambs

1992 ◽  
Vol 33 (1) ◽  
pp. 95-111 ◽  
Author(s):  
Hiroshi KATAYAMA ◽  
William HENRY ◽  
Carol L. LUCAS ◽  
Belinda HA ◽  
Jose I. FERREIRO ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Pulmonary Blood Flow ◽  
Three Dimensional ◽  
Velocity Profiles

scholarly journals Two-dimensional mitral flow velocity profiles in pig models using epicardial doppler echocardiography

1994 ◽  
Vol 24 (2) ◽  
pp. 532-545 ◽  
Author(s):  
W.Yong Kim ◽  
Thue Bisgaard ◽  
Sten L. Nielsen ◽  
Jens K. Poulsen ◽  
Erik M. Pedersen ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Doppler Echocardiography ◽  
Velocity Profiles ◽  
Two Dimensional ◽  
Mitral Flow

Systolic sequential flow velocity profiles in four currently used bileaflet heart valve prostheses

1993 ◽  
Vol 7 (2) ◽  
pp. 107-108
Author(s):  
J VANSON ◽  
H REUL ◽  
U STEINSEIFER ◽  
B SCHMITZ ◽  
A SCHMID ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Heart Valve ◽  
Velocity Profiles ◽  
Heart Valve Prostheses ◽  
Valve Prostheses

scholarly journals 1028: Flow velocity profiles in the descending aorta in hypertensive disease during pregnancy

2019 ◽  
Vol 220 (1) ◽  
pp. S659-S660
Author(s):  
Yalda Afshar ◽  
Allison Woods ◽  
Greggory DeVore ◽  
Brian Koos
Keyword(s):  
Flow Velocity ◽  
Velocity Profiles ◽  
Hypertensive Disease ◽  
Descending Aorta

scholarly journals Optimal Taylor–Couette flow: direct numerical simulations

2013 ◽  
Vol 719 ◽  
pp. 14-46 ◽  
Author(s):  
Rodolfo Ostilla ◽  
Richard J. A. M. Stevens ◽  
Siegfried Grossmann ◽  
Roberto Verzicco ◽  
Detlef Lohse
Keyword(s):  
Angular Velocity ◽  
Couette Flow ◽  
Scaling Laws ◽  
Outer Cylinder ◽  
Reynolds Numbers ◽  
Velocity Profiles ◽  
Experimental Result ◽  
Counter Rotation ◽  
Taylor Couette ◽  
Taylor Couette Flow

AbstractWe numerically simulate turbulent Taylor–Couette flow for independently rotating inner and outer cylinders, focusing on the analogy with turbulent Rayleigh–Bénard flow. Reynolds numbers of $R{e}_{i} = 8\times 1{0}^{3} $ and $R{e}_{o} = \pm 4\times 1{0}^{3} $ of the inner and outer cylinders, respectively, are reached, corresponding to Taylor numbers $Ta$ up to $1{0}^{8} $. Effective scaling laws for the torque and other system responses are found. Recent experiments with the Twente Turbulent Taylor–Couette (${T}^{3} C$) setup and with a similar facility in Maryland at very high Reynolds numbers have revealed an optimum transport at a certain non-zero rotation rate ratio $a= - {\omega }_{o} / {\omega }_{i} $ of about ${a}_{\mathit{opt}} = 0. 33$. For large enough $Ta$ in the numerically accessible range we also find such an optimum transport at non-zero counter-rotation. The position of this maximum is found to shift with the driving, reaching a maximum of ${a}_{\mathit{opt}} = 0. 15$ for $Ta= 2. 5\times 1{0}^{7} $. An explanation for this shift is elucidated, consistent with the experimental result that ${a}_{\mathit{opt}} $ becomes approximately independent of the driving strength for large enough Reynolds numbers. We furthermore numerically calculate the angular velocity profiles and visualize the different flow structures for the various regimes. By writing the equations in a frame co-rotating with the outer cylinder a link is found between the local angular velocity profiles and the global transport quantities.

Solids flow velocity profiles in mass flow hoppers

1987 ◽  
Vol 42 (4) ◽  
pp. 737-744 ◽  
Author(s):  
H.G. Polderman ◽  
J. Boom ◽  
E. De Hilster ◽  
A.M. Scott
Keyword(s):  
Flow Velocity ◽  
Mass Flow ◽  
Velocity Profiles
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