In gas-solid riser flows, meso-scale structures affect the overall performance significantly. The two-fluid model (TFM) with structure-dependent EMMS (energy-minimization multi-scale) drag coefficient has proved to allow grid-independent solutions of the effect of meso-scale structures, and succeeded in predicting riser flows with the Geldart A particles (Lu et al., 2009, Chem. Eng. Sci., 64: 3427-3447). In this paper, to investigate the effects of particle properties on these meso-scale structures, for all particle types, two-fluid modeling with and without consideration of meso-scale structures were performed and compared. Generally, the modeling with EMMS drag coefficient shows better results than without considering meso-scale structures, but their discrepancy decays with the Archimedes number. (C) 2011 Elsevier Ltd. All rights reserved.