The goal of the present study is to develop experimental and computational tools for the study of concentrated dispersions of solid particles interacting with a liquid. The experimental approach developed uses stereo imaging to track the motions of the visible cores of transparent particles bathed in a liquid of identical refractive index. The capability of the approach is demonstrated by measuring the 3D circulation inside a fluidisation of 1,000 spheres. For the computational approach, Lagrangian dynamics is combined with the meshless Method of Fundamental Solutions. This approach is applied to rigid disks moving in a 2D potential flow. The resulting simulations show how liquid inertia influences the particle motions.