Abstract
Efforts to model accretion disks in the laboratory using Taylor–Couette flow apparatus are plagued with problems due to the substantial impact the end-plates have on the flow. We explore the possibility of mitigating the influence of these end-plates by imposing stable stratification in their vicinity. Numerical computations and experiments confirm the effectiveness of this strategy for restoring the axially-homogeneous quasi-Keplerian solution in the unstratified equatorial part of the flow for sufficiently strong stratification and moderate layer thickness. If the rotation ratio is too large, however, (e.g. Ωo/Ωi=(ri/ro)3/2 where Ωo/Ωi is the angular velocity at the outer/inner boundary and ri/ro is the inner/outer radius) the presence of stratification can make the quasi-Keplerian flow susceptible to the stratorotational instability. Otherwise (e.g. for Ωo/Ωi= (ri/ro)1/2) our control strategy is successful in reinstating a linearly-stable quasi-Keplerian flow away from the end-plates. Experiments probing the nonlinear stability of this flow show only decay of initial finite-amplitude disturbances at a Reynolds number Re = O(104). This
observation is consistent with most recent computational (Ostilla-M ́onico
et al. 2014) and experimental results (Edlund & Ji 2014) at high Re, and reinforces the growing consensus that turbulence in cold accretion disks must rely on additional physics beyond that of incompressible hydrodynamics.
Original language | English |
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Pages (from-to) | 608-630 |
Number of pages | 23 |
Journal | Journal of Fluid Mechanics |
Volume | 791 |
Early online date | 24 Feb 2016 |
DOIs | |
Publication status | Published - Mar 2016 |
Keywords
- flow control
- stratified flows
- Taylor–Couette flow