In this paper infrared thermographic images of falling hot particle curtains are compared to Eulerian-Eulerian Computational Fluid Dynamics (CFD) model simulations. The hot particle curtains were made to fall through a narrow slot in a rectangular box. The shapes of the formed curtains at different slot widths, particle sizes and mass flow rates were predicted using gradient-based image analysis techniques. Small slot width and low mass flow rate situations were found to show excellent correlation. Larger particle sizes led to greater uncertainty in the thermographic data, and large slot width and high mass flow rate CFD simulations were less reliable. (C) 2017 Elsevier B.V. All rights reserved.