Simulations of pulsed centrifugal instabilities in a Taylor-Couette geometry

The pulsed Taylor-Couette flow is studied numerically. A fluid confined between two solidary cylinders rotating with the angular speed, Omega(o) cos omega t, undergoes a periodic destabilization when the rotational speed, Omega(o), is increased. The primary flow, consisting of two Stokes layers developing from each of the cylindrical walls, bifurcates to periodically appearing Taylor vortices. The times of their appearance can be derived from a quasi-steady linear analysis. Both the simulation we have performed, and the experiment we compare to, reproduce the same critical destabilization times. The direct numerical simulation is performed with a spectral element code specifically designed for the Taylor-Couette geometry.