Layer formation and transitions in stratified circular Couette flow

The stability of circular Couette flow with axial density stratification, characterized by the buoyancy frequency N, is considered for various values of the non-dimensional gap width epsilon between the cylinders. It is shown that onset of instability and the structure of the resulting flow regimes - namely, flattened rolls, non-axisymmetric vortices, Taylor vortices and the related density layer formation - strongly depend on N in addition to Reynolds number and E. Experimental results are compared with linear stability theory, and axisymmetric numerical simulations are performed for various Prandtl numbers.