CFD method was used to study the pressure drop in the fixed bed packed with the particles of same and different diameter. PFC3D software was used for modeling of the fixed bed,and Fluent software was used to simulate the pressure field. The working range of the particle Reynolds numbers( Rep) was from 1 to 2 200. Simulated results of the void fraction and pressure drop were compared with calculated results by the semi-empirical equation in published literature,which indicated that at low Rep( Rep<120),a goo...