Large eddy simulations (LES) of Taylor-Couette (TC) flow, the flow between two co-axial and independently rotating cylinders are performed in an attempt to explore the large-scale axially-pinned structures seen in experiments and simulations. Both static and dynamic LES models are used. The Reynolds number is kept fixed at Re = 3.4 • 104, and the radius ratio η = ri/ro is set to η = 0.909, limiting the effects of curvature and resulting in frictional Reynolds numbers of around Reτ ≈ 500. Four rotation ratios from Rot =-0.0909 to Rot = 0.3 are simulated. First, the LES of TC is benchmarked for different rotation ratios. Both the Smagorinsky model with a constant of cs = 0.1 and the dynamic model are found to produce reasonable results for no mean rotation and cyclonic rotation, but deviations increase for increasing rotation. This is attributed to the increasing anisotropic character of the fluctuations. Second, "over-damped" LES, i.e. LES with a large Smagorinsky constant is performed and is shown to reproduce some features of the large-scale structures, even when the near-wall region is not adequately modeled. This shows the potential for using over-damped LES for fast explorations of the parameter space where large-scale structures are found.
|Journal||Journal of physics: Conference series|
|Publication status||Published - 12 Apr 2018|
|Event||3rd Madrid Summer School on Turbulence 2017 - School of Aeronautics of the Universidad Politécnica de Madrid, Madrid, Spain|
Duration: 29 May 2017 → 30 Jun 2017
Conference number: 3