The cavity formation hysteresis phenomenon in packed and spouted beds of particles has been simulated using the Eulerian-Eulerian two-fluid model, incorporating a particle compression mechanism via changing the particle packing limit in Fluent software. The cavity height for the internal jet determined from the simulated results agreed well with the published experimental data. The simulated results also showed that the compaction was most significant in a small region in close contact with the internal jet, causing the extra pressure drop across the whole column. The simulated static pressure drops captured the trend of hysteresis but under estimated the experimental data for the flow ascending process and overestimated the flow descending data. Improved under standing of the particle compaction mechanism in packed and spouted beds is required in order to improve the accuracy of numerical simulations. (c) 2010 Elsevier Ltd. All rights reserved.