scholarly journals An analytical study on the turbulent taylor vortex flow between concentric cylinders. Prediction of the flow field by using the .KAPPA.-.EPSILON. model.

1990 ◽  
Vol 56 (529) ◽  
pp. 2576-2581
Author(s):  
Mutsuo KOBAYASHI ◽  
Hiroshi MAEKAWA ◽  
Takeo TAKAHASHI ◽  
Minoru YOSHIKAWA
Keyword(s):  
Flow Field ◽  
Analytical Study ◽  
Vortex Flow ◽  
Taylor Vortex ◽  
Taylor Vortex Flow ◽  
Concentric Cylinders

Numerical investigation of supercritical Taylor-vortex flow for a wide gap

1984 ◽  
Vol 138 ◽  
pp. 21-52 ◽  
Author(s):  
H. Fasel ◽  
O. Booz
Keyword(s):  
Flow Field ◽  
Vortex Flow ◽  
Numerical Solutions ◽  
Stokes Equations ◽  
Taylor Number ◽  
Taylor Vortex ◽  
Plane Boundary ◽  
Aspect Ratios ◽  
Taylor Vortex Flow ◽  
Wide Gap

For a wide gap (R1/R2= 0.5) and large aspect ratiosL/d, axisymmetric Taylor-vortex flow has been observed in experiments up to very high supercritical Taylor (or Reynolds) numbers. This axisymmetric Taylor-vortex flow was investigated numerically by solving the Navier–Stokes equations using a very accurate (fourth-order in space) implicit finite-difference method. The high-order accuracy of the numerical method, in combination with large numbers of grid points used in the calculations, yielded accurate and reliable results for large supercritical Taylor numbers of up to 100Tac(or 10Rec). Prior to this study numerical solutions were reported up to only 16Tac. The emphasis of the present paper is placed upon displaying and elaborating the details of the flow field for large supercritical Taylor numbers. The flow field undergoes drastic changes as the Taylor number is increased from just supercritical to 100Tac. Spectral analysis (with respect toz) of the flow variables indicates that the number of harmonics contributing substantially to the total solution increases sharply when the Taylor number is raised. The number of relevant harmonics is already unexpectedly high at moderate supercriticalTa. For larger Taylor numbers, the evolution of a jetlike or shocklike flow structure can be observed. In the axial plane, boundary layers develop along the inner and outer cylinder walls while the flow in the core region of the Taylor cells behaves in an increasingly inviscid manner.

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.

Experimental Study on the Effects of Surface Roughness on the Behaviors of Hydrodynamic Instabilities of Couette-Taylor Flow

2017 ◽  
Author(s):  
Mostafa Monfared ◽  
Lamia Gaied ◽  
Emna Berrich ◽  
Ebrahim Shirani ◽  
Maxence Bigerelle ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Vortex Flow ◽  
Outer Cylinder ◽  
Wire Mesh ◽  
Taylor Vortex ◽  
Hydrodynamic Instabilities ◽  
Taylor Flow ◽  
Taylor Vortex Flow ◽  
Concentric Cylinders ◽  
Effect Of Surface

Couette-Taylor flow is a type of fluid flow that occurs in the annulus between differentially concentric cylinders, when the outer cylinder is fixed and the inner cylinder rotates and the rotation rate exceeds a critical value. In this research we have studied the effect of surface roughness on the hydrodynamic structures of Couette-Taylor Flow. The PIV technique has been applied for flow visualization. At first, for a smooth surface, the different flow patterns include Couette flow, Taylor vortex flow, wavy vortex flow, modulated wavy vortex flow and turbulent flow. They are investigated numerically and experimentally. The transition Taylor number for every flow regime is also taken into consideration. The results showed that the numerical results correspond quite well to the experimental data. Then, the different surface conditions for inner cylinder which are studied are: a smooth one, a sandpaper-type P180, a canvas plastic with different wire-mesh roughness. They are used to study the effects of surface roughness on the flow structures and critical Taylor numbers. The experimental results showed that the roughness causes a delay in the appearance of the first instabilities.

Centrifugal instabilities of circumferential flows in finite cylinders: nonlinear theory

1980 ◽  
Vol 372 (1750) ◽  
pp. 317-356 ◽  
Keyword(s):  
Vortex Flow ◽  
Outer Cylinder ◽  
Perturbation Expansion ◽  
Direct Consequence ◽  
Finite Amplitude ◽  
Taylor Vortex ◽  
Taylor Vortex Flow ◽  
Concentric Cylinders ◽  
Axisymmetric Disturbances ◽  
Finite Cylinders

In an earlier paper, Blennerhassett & Hall (1979) investigated the linear stability of the flow between concentric cylinders of finite length. The inner cylinder was taken to rotate, while the outer cylinder was fixed. Furthermore, the end walls rotated such that the flow was purely circumferential. In this paper the finite amplitude development of the unstable disturbances to the flow is considered. It is found that the usual perturbation expansion of nonlinear stability theory must be modified if the cylinders are not infinitely long. The bifurcation to a Taylor vortex flow in finite cylinders is shown to be two-sided. The latter effect is shown to be a direct consequence of the finiteness of the cylinders and by taking the cylinders to be very long, we recover the results obtained previously for the infinite problem. The interaction of the two most dangerous modes of linear theory is also investigated. For certain values of the length of the cylinders the initial finite amplitude Taylor vortex flow is shown to become unstable to another class of axisymmetric disturbances. The effect of perturbing the end conditions towards the no-slip conditions appropriate to most experimental configurations is also discussed. Some discussion of the instability problem in very long cylinders with fixed ends is given.

scholarly journals An experimental study on turbulent taylor vortex flow between concentric cylinders.

1989 ◽  
Vol 55 (517) ◽  
pp. 2581-2589
Author(s):  
Mutsuo KOBAYASHI ◽  
Hiroshi MAEKAWA ◽  
Tsuyoshi TAKANO ◽  
Yukihide YAMADA
Keyword(s):  
Experimental Study ◽  
Vortex Flow ◽  
Taylor Vortex ◽  
Taylor Vortex Flow ◽  
Concentric Cylinders

scholarly journals Hydrodynamic education with rheoscopic fluid

2019 ◽  
Vol 213 ◽  
pp. 02014
Author(s):  
Daniel Duda ◽  
Marek Klimko ◽  
Radek Škach ◽  
Jan Uher ◽  
Václav Uruba
Keyword(s):  
Vortex Flow ◽  
Maximum Stress ◽  
Fluid Motion ◽  
Shear Layers ◽  
Taylor Vortex ◽  
Taylor Vortices ◽  
Taylor Vortex Flow ◽  
Concentric Cylinders ◽  
The Subject

We present a educational poster supporting the subject „Mechanics of fluids I“, which the students evaluate to be difficult mainly due to abstractness. Our goal is to show in vivo the behavior, especially the non-linearity, of various flows transiting into turbulence. The fluid motion is visualized by using the rheoscopic fluid, which consist of water and the dust of mica, whose particles are longitudinal and shiny resulting into easily observable reflections, when the particles coherently orient along the maximum stress. This happens mainly in shear layers, e.g. at the boundary between vortex core and envelope. An example of flow transiting into turbulence is the Taylor-Couette flow between two concentric cylinders, which with increasing Taylor number passes through various regimes from fully laminar bearing flow through the Taylor vortex flow (TVF) and later Wavy vortex flow (WVF) up to Turbulent Taylor vortices regime (TTV) and, finally, the regime of featureless turbulence.

On the mathematics of Taylor-vortex flows in cylinders of finite length

1980 ◽  
Vol 372 (1750) ◽  
pp. 357-365 ◽  
Keyword(s):  
Boundary Conditions ◽  
Finite Length ◽  
Vortex Flow ◽  
Taylor Vortex ◽  
Vortex Flows ◽  
Special Boundary ◽  
Amplitude Equations ◽  
Taylor Vortex Flow ◽  
Concentric Cylinders

A study is made of Taylor-vortex flow between two concentric cylinders of finite length by means of a formulation in terms of amplitude equations. With special boundary conditions and in a certain limit, it is shown that the bifurcation to Taylor-vortex flow is supercritical rather than transcritical. The relevance of this for comparison with observation is discussed.

Sign in / Sign up

Export Citation Format

Share Document