ROTATING AXIAL-FLOW OF A CONTINUOUSLY SEPARATING MIXTURE

We consider the continuous separation process of a monodispersed suspe nsion flowing axially through a rotating circular cylinder. This stati onary problem can be regarded as a basic flow case of rotating mixture s in conjunction with previous studies of time-dependent flows like sp in-up and batch settling in a cylinder. The 'mixture model' for two-ph ase flow is used to formulate the problem, which is solved in the rang e of small Ekman and Rossby numbers by asymptotic analytical methods a nd by a numerical code. The gradual separation of the axially injected suspension is manifested as a stationary stratification of the mixtur e which induces a swirl component of the velocity, in analogy with the thermal wind in the Earth's atmosphere. The presence of the azimuthal motion and induced secondary flow due to Ekman-layer pumping clearly influences the character of the stratification. Analytical and numeric al results are in excellent agreement.