The primary objective of this study is to numerically investigate the influence of various geometries of flow modifying centre-bodies on the aerodynamics of flow in the plenum chamber of a swirling fluidized bed. Ten different hub geometries, in the shape of cylinder, cone, conical frustum or a combination of these are considered in the study. Two performance characteristics of interest are flow uniformity at the exit plane of the plenum chamber and the total pressure drop across the plenum. The homogeneity of airflow was assessed from a statistical analysis conducted. From the results, it is evident that the introduction of a full-length cylindrical hub at the centre of the plenum chamber offers a balance in the required performance characteristics. © 2009-2012.