Numerical study of MHD Taylor vortex flow with low magnetic Reynolds number in finite-length annulus under uniform magnetic field

2014 ◽  
Vol 105 ◽  
pp. 16-27 ◽  
Author(s):  
Xue-Yuan Leng ◽  
Yang Yu ◽  
Ben-Wen Li
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Finite Length ◽  
Uniform Magnetic Field ◽  
Vortex Flow ◽  
Numerical Study ◽  
Magnetic Reynolds Number ◽  
Taylor Vortex ◽  
Taylor Vortex Flow

Numerical Study of Effects of Initial Flow Field on Taylor Vortex Flow

2007 ◽  
Author(s):  
H. Furukawa ◽  
M. Hanaki ◽  
T. Watanabe
Keyword(s):  
Flow Field ◽  
Vortex Flow ◽  
Numerical Study ◽  
Outer Cylinder ◽  
Visual Observation ◽  
Taylor Vortex ◽  
Initial Flow ◽  
Taylor Vortex Flow ◽  
The Difference ◽  
Mode Formation

In concentrically rotating double cylinders consisting of a stationary outer cylinder and a rotating inner cylinder, Taylor vortex flow appears. Taylor vortex flow occurs in journal bearings, various fluid machineries, containers for chemical reaction, and other rotating components. Therefore, the analysis of the flow structure of Taylor vortex flow is highly effective for its control. The main parameters that determine the modes of Taylor vortex flow of a finite length are the aspect ratio Γ, Reynolds number Re. Γ is defined as the ratio of the cylinder length to the gap length between cylinders, and Re is determined on the basis of the angular speed of the inner cylinder. Γ was set to be 3.2, 4.8 and 6.8, and Re to be values in the range from 100 to 1000 at intervals of 100. Thus far, a large number of studies on Taylor vortex flow have been carried out; however, the effects of the differences in initial conditions have not yet been sufficiently clarified. In this study, we changed the initial flow field between the inner and outer cylinders in a numerical analysis, and examined the resulting changes in the mode formation and bifurcation processes. In this study, the initial speed distribution factor α was defined to be a function of the initial flow field and set to be 1.0, 0.999, 0.9 and 0.8 for the calculation. As a result, a difference was observed in the final mode depending on the difference in α for each Γ. From this finding, non-uniqueness, which is a major characteristic of Taylor vortex flow, was confirmed. However, no regularities regarding the difference in mode formation were found and the tendency of the mode formation process was not specified. Moreover, the processes of developing the vortex resulting in different final modes were monitored over time by visual observation. Similar flow behaviors were initially observed after the start of the calculation. Then, a bifurcation point, at which the flow changed to a mode depending on α, was observed, and finally the flow became steady. In addition, there was also a difference in the time taken for the flow to reach the steady state. These findings are based on only visual observation. Accordingly, a more detailed analysis at each lattice point and a comparison of physical quantities, such as kinetic energy and enstrophy, will be our future tasks.

Forming Process of Taylor Vortex Flow of Polymer Solutions

2004 ◽  
Author(s):  
Shu Sumio ◽  
Keizo Watanabe ◽  
Satoshi Ogata
Keyword(s):  
Reynolds Number ◽  
Flow Visualization ◽  
Vortex Flow ◽  
Polymer Solutions ◽  
Newtonian Fluids ◽  
Experimental Result ◽  
Taylor Vortex ◽  
Number Range ◽  
Primary Mode ◽  
Taylor Vortex Flow

The laser-induced fluorescence (LIF) technique carried out the flow visualization for the formation of Taylor vortex, which occurred in the gap between the two coaxial cylinders. The test fluids were tap water and glycerin 60wt% solution as Newtonian fluids. Polyacrilamide (SeparanAP-30) solutions in the concentration range of 10 ppm to 1000 ppm and polyethylene-oxide (PEO15) solutions in the range of 20 ppm to 1000 ppm were tested as non-Newtonian fluids, respectively. The Reynolds number range was 80 < Re < 4.0 × 103 in the experiment. The rotating inner cylinder was accelerated under the slow condition (dRe*/ dt ≤ 1 min−1) in order to obtain a Taylor vortex flow of the stable primary mode. Flow visualization results showed that the Go¨rtler vortices of half the number of Taylor cells occurred in the gap when Taylor vortex flow of the primary mode was formed. In addition, the critical Reynolds number of the polymer solutions case, which Taylor vortices occur, because the generation of the Go¨rtler vortices was retarded. At the higher concentration of the polymer solutions, this effect became remarkable. Measurements of steady-state Taylor cells showed that the upper and the lower cells of polymer solutions became larger in wavelength than that of the Newtonian fluids. The Taylor vortex flow of non-Newtonian fluids was analyzed and the result of the Giesekus model agreed with the experimental result.

628 Numerical study of initial condition in Taylor vortex flow

2006 ◽  
Vol 2006.19 (0) ◽  
pp. 525-526
Author(s):  
Masashi HANAKI ◽  
Hiroyuki FURUKAWA ◽  
Takashi WATANABE
Keyword(s):  
Vortex Flow ◽  
Numerical Study ◽  
Taylor Vortex ◽  
Initial Condition ◽  
Taylor Vortex Flow

Numerical study on pattern formation process in Taylor vortex flow

2000 ◽  
Vol 2000.4 (0) ◽  
pp. 249-250
Author(s):  
Hiroyuki FURUKAWA ◽  
Takashi WATANABE ◽  
Ikuo NAKAMURA
Keyword(s):  
Pattern Formation ◽  
Formation Process ◽  
Vortex Flow ◽  
Numerical Study ◽  
Taylor Vortex ◽  
Taylor Vortex Flow

3937 Numerical study of sampling flow information in Taylor vortex flow

2006 ◽  
Vol 2006.7 (0) ◽  
pp. 155-156
Author(s):  
Makoto HAMANO ◽  
Hiroyuki FURUKAWA ◽  
Takashi WATANABE
Keyword(s):  
Vortex Flow ◽  
Numerical Study ◽  
Taylor Vortex ◽  
Taylor Vortex Flow ◽  
Flow Information ◽  
Sampling Flow

The Effect of Taylor Vortex Flow on the Development Length in Concentric Annuli

1979 ◽  
Vol 21 (2) ◽  
pp. 59-64 ◽  
Author(s):  
D. A. Simmers ◽  
J. E. R. Coney
Keyword(s):  
Reynolds Number ◽  
Vortex Flow ◽  
Outer Cylinder ◽  
Outer Wall ◽  
Taylor Vortex ◽  
Rotational Flow ◽  
Development Length ◽  
Full Development ◽  
Annular Gap ◽  
Taylor Vortex Flow

Results are presented of an investigation into a developing, combined axial and rotational flow in an annular gap formed by a stationary outer cylinder and a rotatable inner cylinder for an annulus radius ratio of 0–8 and an axial Reynolds number of 1200. These results show that, in the Taylor vortex flow régime, the development length decreases with the parameter Re2a/Ta and that the greatest development length in an annular gap, for a given axial Reynolds number, occurs when the Taylor number is near to its critical value. Consideration of isothermal heat transfer through the outer wall of the annular gap suggests that, in the development of the flow, the Nusselt number rises to a high value before falling to a constant value, at full development.

MHD flow in a rectangular duct with pairs of conducting and non-conducting walls in the presence of a non-uniform magnetic field

1980 ◽  
Vol 96 (2) ◽  
pp. 335-353 ◽  
Author(s):  
Richard J. Holroyd
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Reynolds Number ◽  
Uniform Magnetic Field ◽  
Hartmann Number ◽  
Mhd Flow ◽  
Magnetic Reynolds Number ◽  
Rectangular Duct ◽  
Mean Velocity ◽  
Side Walls

A theoretical and experimental study has been carried out on the flow of a liquid metal along a straight rectangular duct, whose pairs of opposite walls are highly conducting and insulating, situated in a planar non-uniform magnetic field parallel to the conducting walls. Magnitudes of the flux density and mean velocity are taken to be such that the Hartmann numberMand interaction parameterNhave very large values and the magnetic Reynolds number is extremely small.The theory qualitatively predicts the integral features of the flow, namely the distributions along the duct of the potential difference between the conducting walls and the pressure. The experimental results indicate that the velocity profile is severely distorted by regions of non-uniform magnetic field with fluid moving towards the conducting walls; even though these walls are very good conductors the flow behaves more like that in a non-conducting duct than that predicted for a duct with perfectly conducting side walls.

Formation of Taylor Vortex Flow of Polymer Solutions

2005 ◽  
Vol 128 (1) ◽  
pp. 95-100 ◽  
Author(s):  
Keizo Watanabe ◽  
Shu Sumio ◽  
Satoshi Ogata
Keyword(s):  
Reynolds Number ◽  
Flow Visualization ◽  
Vortex Flow ◽  
Polymer Solutions ◽  
Newtonian Fluids ◽  
Taylor Vortex ◽  
Primary Mode ◽  
Görtler Vortices ◽  
Taylor Vortex Flow ◽  
Gortler Vortices

Laser-induced fluorescence (LIF) was applied for the flow visualization of the formation of a Taylor vortex, which occurred in the gap between two coaxial cylinders. The test fluids were tap water and glycerin 60 %wt solution as Newtonian fluids; polyacrilamide (SeparanAP-30) solutions in the concentration range of 10 to 1000ppm and polyethylene-oxide (PEO15) solutions in the range of 20 to 1000ppm were tested as non-Newtonian fluids. The Reynolds number range in the experiment was 80<Re<4.0×103. The rotating inner cylinder was accelerated under the slow condition (dRe*∕dt⩽1min−1) in order to obtain a Taylor vortex flow in stable primary mode. Flow visualization results showed that the Görtler vortices of half the number of the Taylor cells occurred in the gap when the Taylor vortex flow was formed in the primary mode. In addition, the critical Reynolds number of the polymer solutions increased, where Taylor vortices occur, because the generation of the Görtler vortices was retarded. In high concentration polymer solutions, this effect became remarkable. Measurements of steady-state Taylor cells showed that the upper and lower cells of polymer solutions became larger in wavelength than those of the Newtonian fluids. The Taylor vortex flow of non-Newtonian fluids was analyzed and the result obtained using the Giesekus model agreed with the experimental result.

The force on a sphere moving through a conducting fluid in the presence of a magnetic field

1961 ◽  
Vol 11 (1) ◽  
pp. 133-142 ◽  
Author(s):  
J. R. Reitz ◽  
L. L. Foldy
Keyword(s):  
Magnetic Field ◽  
Reynolds Number ◽  
Pressure Distribution ◽  
Magnetic Field Line ◽  
Potential Flow ◽  
Uniform Magnetic Field ◽  
Magnetic Reynolds Number ◽  
Conducting Fluid ◽  
Joule Dissipation ◽  
Hydrodynamic Motion

The force on a sphere moving through an inviscid, conducting fluid in the presence of a uniform magnetic field B0 is calculated for the low-conductivity case where the hydrodynamic motion deviates only slightly from potential flow. The magnetic Reynolds number is assumed small. The force on the sphere is found to consist of both a drag and a deflective component which tends to orient its motion parallel to a magnetic field line; if the sphere's velocity is V, the force may be written $\bf {R} = -AB^2_0\bf {V} + \bf C(V.B_0)B_0$ where the coefficients A and C depend on the conductivities of both sphere and fluid. The coefficients are evaluated by calculating the Joule dissipation for particular orientations of V relative to B0. In one case the force is also calculated directly from the perturbed pressure distribution in the fluid. In an analogous way, a spinning sphere in a conducting fluid experiences both resistive and gyroscopic torques.

Sign in / Sign up

Export Citation Format

Share Document