Impact of noise on the onset of vortex breakdown

The effects of noise on the onset of vortex breakdown in an enclosed cylinder driven by the rotation of an endwall is investigated using a novel approach in which the stochasticity is introduced physically via the boundary conditions, leading to a system with stochastic parametric forcing. A novel temporal reduction of the stochastic problem to a mean flow problem and a stochastic correction problem involving a random Wiener process whose characteristics explicitly depend on the mean solution and the type of noise, is used in order to make the problem tractable.