| The asymptotic analysis for linear flow in a rapidly rotating container with no particles is successfully completed with the exception of a very small zone in the vicinity of the exhaust region. The results for linear flow from the numerical analysis agree with the asymptotic linear theory results, and exhibit secondary circulation patterns within the geostropic region. Even under linear and weakly non-linear flow conditions, numerical results show that the flow within the exhaust region exhibits unique flow reversals. These reversals are found to be a strong function of the inlet flow rate, the angular velocity of the chamber and the exit tube diameter.; The non-linear, laminar flow studies show a strong decoupling between the tangential velocity, and the radial and axial velocities. The flow field is found to be dominated by the source layer and exhaust flow. In addition, the Ekman layers do not have a chance to develop, and thus, do not have a strong influence on the flow field. Again, flow reversals are seen in the exit region. In this study, a {dollar}k{dollar}-{dollar}epsilon{dollar} two-equation model with a flux Richardson number is used to describe turbulence. The numerical results for turbulent flow are in surprisingly good agreement with the available hot wire anemometer data.; For the case of linear flow in a rotating cylinder with porous medium, asymptotic and numerical analyses show good agreement. The calculated parallel streamlines indicate that the axial gradients of the velocities are negligible within the packed medium. The flow in the freeboard region was found to be the same as in the case of linear flow without packed media. The numerical results obtained for turbulent flow in a system with packed particles exhibit unexpected flow reversals near the porous medium-freeboard interface. As a result of these primary circulation zones, the axial gradients of the variables are no longer negligible, as they are for the linear flow.; The case of turbulent flow with packed particles simulates a rotating fluidized bed; therefore, the numerical results provide a description of the mechanics of flow and entrainment. The numerical results confirm that a partial fluidization of particles is likely to occur. (Abstract shortened with permission of author.)... |
