Taylor-Couette flow stability: effect of vertical density stratification and azimuthal magnetic fields

2004 ◽  
Author(s):  
Dima Shalybkov
Keyword(s):  
Magnetic Fields ◽  
Couette Flow ◽  
Flow Stability ◽  
Density Stratification ◽  
Vertical Density ◽  
Taylor Couette ◽  
Stability Effect ◽  
Taylor Couette Flow

Instabilities and transient growth of the stratified Taylor–Couette flow in a Rayleigh-unstable regime

2017 ◽  
Vol 822 ◽  
pp. 80-108 ◽  
Author(s):  
Junho Park ◽  
Paul Billant ◽  
Jong-Jin Baik
Keyword(s):  
Couette Flow ◽  
Density Stratification ◽  
Rotational Instability ◽  
Transient Growth ◽  
Unstable Regime ◽  
Stable Regime ◽  
Energy Growth ◽  
Centrifugal Instability ◽  
Taylor Couette ◽  
Taylor Couette Flow

The stability of the Taylor–Couette flow is analysed when there is a stable density stratification along the axial direction and when the flow is centrifugally unstable, i.e. in the Rayleigh-unstable regime. It is shown that not only the centrifugal instability but also the strato-rotational instability can occur. These two instabilities can be explained and well described by means of a Wentzel–Kramers–Brillouin–Jeffreys asymptotic analysis for large axial wavenumbers in inviscid and non-diffusive limits. In the presence of viscosity and diffusion, numerical results reveal that the strato-rotational instability becomes dominant over the centrifugal instability at the onset of instability when the axial density stratification is sufficiently strong. Linear transient energy growth is next investigated for counter-rotating cylinders in the stable regime of the Froude number–Reynolds number parameter space. We show that there exist two types of transient growth mechanism analogous to the lift up and the Orr mechanisms in homogeneous fluids but with the additional effect of density perturbations. The dominant mechanism depends on the stratification: when the stratification is strong, non-axisymmetric three-dimensional perturbations achieve the optimal energy growth through the Orr mechanism while for moderate stratification, axisymmetric perturbations lead to the optimal transient growth by a lift-up mechanism involving internal waves.

Taylor-Couette flow stability of diabetic blood

2016 ◽  
Vol 9 (6) ◽  
pp. 989-998
Author(s):  
D.E. McMillan ◽  
J. Strigberger ◽  
N.G. Utterback ◽  
N. Romanoff
Keyword(s):  
Couette Flow ◽  
Flow Stability ◽  
Taylor Couette ◽  
Taylor Couette Flow
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