Comparison of direct simulations and κ-ε modeling for flows between two disks with a rotor-stator configuration

The structure of turbulent flow within a rotor-stator enclosure is investigated using two different methodologies. The first one consists of integrating the unsteady Navier-Stokes equations to determine its statistical moments. The numerical algorithm integrates the equations in stream function-vorticity formulation using second order space centred approximations and a second order time stepping scheme, This algorithm was implemented on a parallel machine through an algebraic multi domain decomposition technique. The second consists of integrating the Reynolds averaged equations with a kappa-epsilon model accounting for rotation effects. After a brief discussion of the space-time structure of the unsteady solutions, comparisons between the results produced by both methods are performed. We analyze the differences on the turbulence kinetic budgets whose main consequence is an underestimation of the angular velocity in the core region. (C) Elsevier, Paris.