A parameter study of strato-rotational low-frequency modulations: impacts on momentum transfer and energy distribution

  • Meletti, Gabriel (University of Lyon 1 claude bernard)
  • Abide, Stephane (Universit√© de Perpignan Via Domitia)
  • Harlander, Uwe (Department of Aerodynamics and Fluid Mechanic)
  • Viazzo, Stephane (Aix Marseille Univ, CNRS, Centrale Marseille,)

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Previous comparisons of experimental data with non-linear numerical simulations of density stratified Taylor-Couette flows revealed non-linear interactions of strato-rotational instability (SRI) modes that lead to periodic changes in the SRI spirals and their axial propagation. These pattern changes are associated to low-frequency velocity modulations that are related to the dynamics of two competing spiral wave modes propagating in opposite directions. In the present exposition, a parameter study of the strato-rotational instability (SRI) is performed using Direct Numerical Simulations to evaluate the influence of the Reynolds numbers, the stratification, and of the container geometry on these SRI low-frequency modulations and spiral pattern changes. The results of this parameter study show that the modulations can be considered as a secondary instability that is not observed for all SRI unstable regimes. The findings are of interest when the Taylor-Couette model is related to star formation processes in accretion disks.