A virtual experimentation combining computational fluid dynamics (CFD) and computed tomography (CT) simulations was presented to evaluate the beam hardening effect in the CT application to multiphase flow measurement. A semi-industrial scale circulating fluidized bed (CFB) reactor was simulated with a multiscale CFD approach, and its computed flow fields was taken as the dynamic phantom for CT. By this means, a 3rd generation X-ray CT with different filter parameters was simulated. Since the computed flow fields can be manipulated in detail and reproduced at will, this virtual approach enables quantitative evaluation of the beam hardening effect and helps establish the optimal filter parameters for CT measurement of multiphase flow. (C) 2009 Elsevier B.V. All rights reserved.