DNS of the Taylor-Couette flows in the short configurations with co- and counter-rotating cylinders
[ 1 ] Instytut Energetyki Cieplnej, Wydział Inżynierii Środowiska i Energetyki, Politechnika Poznańska | [ P ] pracownik
2022
abstrakt
angielski
- przepływy Taylora-Couetta
- niestabilność
- DNS
- przepływy Keplera
EN In the Taylor–Couette configurations with differentially rotating cylinders the large variety of the flow states connected with the lam.–turb. transitional flow and the fully turbulent flow is observed. The author reports on the 3D direct numerical simulations (DNS) of the transitional flow between the co- and counter-rotating cylinders with the end-walls attached to the inner cylinder. The flow examples with the following rotational rates α=Ωout/Ωin=-0.5, -0.4, -0.2, 0, +0.1, +0.2, +0.3 are analyzed (this range of α corresponds to the values of rotational number RΩ from the range (-1.14; 0.0)). The other parameters are as follows: radius ratio of η=0.5, aspect ratio from the range Γ=3.8 - 4.05, Reynolds number up to Rein=3000. The results are verified by comparing the radial profiles of the averaged (in time, azimuthal and axial directions) circumferential velocity component with those published in literature and by comparing the global structures observed for Rein=2000-3000 (α=Ωout/Ωin=+0.2, +0.3). The r.m.s velocity fluctuations and the Reynolds stress tensor components profiles are analyzed. The flow visualization is performed using the λ2 method.
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