In practical applications, the particles in a bubbling fluidized bed are usually irregularly shaped. The gas-solid flow behavior of black millet particles with ellipsoidal shape was numerically and experimentally investigated. In the present work, a two-fluid model with a modified Gidaspow drag model has been built in a gas-solid bubbling bed to investigate the flow behavior of particles with irregular shape. Particle sphericities are taken into account in the Gidaspow drag model, which is a significant factor affecting the flow behavior of irregularly shaped particles. Particle concentration and velocity distribution were studied at various inlet superficial gas velocities and initial bed heights. Numerical results were compared with experimental results obtained by PIV (Particle Image Velocimetry). It is shown that the simulation results using the modified Gidaspow drag model are in better agreement with the experimental results than using the original one, which indicates that the modified Gidaspow model is better suited for irregularly shaped particles. (C) 2015 Elsevier B.V. All rights reserved.