Using stratification to mitigate end-effects in quasi-Keplerian Taylor-Couette flow
Journal of Fluid Mechanics
Cambridge University Press
MetadataShow full item record
Leclercq, C., Partridge, J. L., Augier, P., Dalziel, S., & Kerswell, R. (2016). Using stratification to mitigate end-effects in quasi-Keplerian Taylor-Couette flow. Journal of Fluid Mechanics, 791 608-630. https://doi.org/10.1017/jfm.2016.44
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-Mónico 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.
We gratefully acknowledge the support of EPSRC under grant EP/K034529/1.
External DOI: https://doi.org/10.1017/jfm.2016.44
This record's URL: https://www.repository.cam.ac.uk/handle/1810/253304