scholarly journals Experimental Study for Spherical Couette Flow in Magnetic Fluid. Torque Characteristics for Outer Sphere Rotation.

1994 ◽  
Vol 60 (573) ◽  
pp. 1627-1631
Author(s):  
Hiroshi Yamaguchi ◽  
Itaru Kobori ◽  
Yuu Fujitani
Keyword(s):  
Experimental Study ◽  
Couette Flow ◽  
Magnetic Fluid ◽  
Outer Sphere ◽  
Spherical Couette Flow ◽  
Spherical Couette

scholarly journals Rotating spherical Couette flow in a dipolar magnetic field: experimental study of magneto-inertial waves

2008 ◽  
Vol 604 ◽  
pp. 175-197 ◽  
Author(s):  
DENYS SCHMITT ◽  
T. ALBOUSSIÈRE ◽  
D. BRITO ◽  
P. CARDIN ◽  
N. GAGNIÈRE ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Couette Flow ◽  
Outer Sphere ◽  
Liquid Sodium ◽  
Inertial Waves ◽  
Spherical Couette Flow ◽  
Rotation Rates ◽  
Inertial Characteristic ◽  
Spherical Couette ◽  
Hydromagnetic Waves

The magnetostrophic regime, in which Lorentz and Coriolis forces are in balance, has been investigated in a rapidly rotating spherical Couette flow experiment. The spherical shell is filled with liquid sodium and permeated by a strong imposed dipolar magnetic field. Azimuthally travelling hydromagnetic waves have been put in evidence through a detailed analysis of electric potential differences measured on the outer sphere, and their properties have been determined. Several types of wave have been identified depending on the relative rotation rates of the inner and outer spheres: they differ by their dispersion relation and by their selection of azimuthal wavenumbers. In addition, these waves constitute the largest contribution to the observed fluctuations, and all of them travel in the retrograde direction in the frame of reference bound to the fluid. We identify these waves as magneto-inertial waves by virtue of the close proximity of the magnetic and inertial characteristic time scales of relevance in our experiment.

scholarly journals Experimental study of super-rotation in a magnetostrophic spherical Couette flow

2006 ◽  
Vol 100 (4-5) ◽  
pp. 281-298 ◽  
Author(s):  
H.-C. Nataf ◽  
T. Alboussière ◽  
D. Brito ◽  
P. Cardin ◽  
N. Gagnière ◽  
...  
Keyword(s):  
Experimental Study ◽  
Couette Flow ◽  
Spherical Couette Flow ◽  
Spherical Couette

Spherical Couette flow of Oldroyd 8-constant model Part I. Solution up to the second-order approximation

2006 ◽  
Vol 84 (5) ◽  
pp. 345-364 ◽  
Author(s):  
A Abu-El Hassan
Keyword(s):  
Couette Flow ◽  
Order Approximation ◽  
Order Term ◽  
Additional Term ◽  
Outer Sphere ◽  
Second Order ◽  
Spherical Couette Flow ◽  
Second Order Approximation ◽  
First Order ◽  
Spherical Couette

The steady flow of an incompressible Oldroyd 8-constant fluid in the annular region between two spheres, or so-called spherical Couette flow, is investigated. The inner sphere rotates with anangular velocity Ω about the z-axis, which passes through the center of the spheres, while the outer sphere is kept at rest. The viscoelasticity of the fluid is assumed to dominate the inertia such that the latter can be neglected in the momentum equation. An analytical solution is obtained through the expansion of the dynamical variables in a power series of the dimensionless retardation time. The leading velocity term denotes the Newtonian rotation about the z-axis. The first-order term results in a secondary flow represented by the stream function that divides the flow region into four symmetric parts. The second-order term is the viscoelastic contribution to the primary viscous flow. The first-order approximation depends on the viscosity and four of the material time-constants of the fluid. The second-order approximation depends on the eight viscometric parameters of the fluid. The torque acting on the outer sphere has an additional term due to viscoelasticity that depends on all the material parameters of the fluid under consideration. For an Oldroyd-B fluid this contributed term enhances the primary torque but in the case of fluids with higher elasticity the torque components may be enhanced or diminished depending on the values of the viscometric parameters.PACS Nos.: 47.15.Rq

scholarly journals Подавление турбулентности в течениях с вращением

2019 ◽  
Vol 45 (17) ◽  
pp. 20
Author(s):  
Д.Ю. Жиленко ◽  
О.Э. Кривоносова
Keyword(s):  
Laminar Flow ◽  
Couette Flow ◽  
Outer Sphere ◽  
Modulation Amplitude ◽  
Flow State ◽  
Turbulence Control ◽  
Spherical Couette Flow ◽  
Rate Modulation ◽  
Narrow Frequency Band ◽  
Spherical Couette

The possibilities of turbulence control in spherical Couette flow were examined experimentally. It was shown, that with increasing of outer sphere rotational rate modulation amplitude, the suppression of turbulence is possible with transition to laminar flow state. The reverse process - turbulence recovery - is available with amplitude decreasing. It was established that turbulence breaking and recovering is accompanied by hysteresis. It was shown, that at small values of modulation amplitude, suppression of turbulence is available only in narrow frequency band.

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