Single-phase flow in a pulsed column: Particle Image Velocimetry validation of a CFD based model

The pulsed column is a widely used technology for liquid-liquid extraction processes in various industries. A thorough understanding of the biphasic flow in the column is essential to achieve process optimization and design. This paper is dedicated to the modelling of the single-phase flow which is strongly influencing the transport, breakage and coalescence of droplets in the apparatus. In this aim, a Computational Fluid Dynamics (CFD) model was developed for the simulation of a disc and doughnut pulsed column. To discuss the relevance of the RANS-based CFD model, the simulation results have been compared to Particle Image Velocimetry (PIV) measurements synchronized on the pulsation period. Since the behaviour of the dispersed phase is strongly dependent on the turbulent properties of the flow, such as eddies size and dissipation rate, the discussion is focussed on turbulent quantities. In this aim, 3D simulations were first carried out and compared to 2D axisymmetric ones. Then, different numerical schemes and turbulence models were compared to experimental data to choose the model offering the most accurate modelling of the single-phase flow.