NONLINEAR SPIRALS IN THE TAYLOR-COUETTE PROBLEM

We examine non-linear spiral flow in the Taylor-Couette problem for a wide gap with axially periodic conditions. We present a highly efficie nt computational method adapted to this problem, based on continuation methods applied to a pseudospectral discretization of the Navier-Stok es equations in a rotating frame of reference. The spiral flow is comp uted in a wide range of parameters, and different features are explore d in detail: domain of existence of the flow, behavior for high Reynol ds number, appearance of axial flows, dependency on parameters, and st ability against helical disturbances. A first integral is obtained and used to describe the particle trajectories in the fluid. This descrip tion shows that the axial and radial motion of the particles is mainly confined within an internal boundary layer. (C) 1998 American Institu te of Physics.