This paper discusses the role of the gas injection pattern on the large scale structures in a homogeneous pseudo-2D bubble column operated at relatively high gas hold-ups up to 8% Seven cases with different inlet configuration have been studied experimentally by Harteveld et al. Each of these cases has been simulated using a (parallel) Euler-Lagrange model developed by Darmana et al. The presence of coherent structures for both uniform and non-uniform gas injection is studied. Furthermore, the influence of the gas injection pattern on the dynamics is investigated, while the statistical (average and fluctuating) quantities are compared with the PIV/PTV and LDA measurement data of Harteveld et al. The results show that the model resembles the observed experimental flow structures to a large extent. (C) 2009 Elsevier Ltd. All rights reserved.