This paper uses a simple separated flow model based on the classical work of Davidson (1961) to describe the complex dynamics in bubbling fluidized beds. It shows that this application is robust and independent of geometry and gas flow conditions. The model successfully simulates the pressure measurements made in a bubbling fluidized bed and it is shown that the single measurement of pressure can be used to characterise the entire fluidized bed . The successful application of the Davidson model suggests that the flow field and hence pressure field in a bubbling fluidized bed is dominated by the size and location of voids, and once given this, particle-particle or complex particle-fluid interactions make a minor direct contribution to the pressure field. (C) 2011 Elsevier Ltd. All rights reserved.