• thin film flow;
  • particle migration;
  • suspensions;
  • viscous roll waves;
  • two-layer film flow


A finite volume method is proposed to study the dynamics of unsteady, falling liquid films carrying monodisperse spheres in Newtonian regime under the action of gravity. The Navier–Stokes equations were rewritten to implement a numerical scheme with interface capturing capability, able to compute discontinuities in the solid volumetric concentration and free surface flows. The interface capturing property is checked with simple benchmarks, showing that experimental data for a vertical settler and the dynamics of the wetting front in a thin liquid film are reproduced with success. Also, the numerical scheme computes with accuracy Kapitza instability or viscous roll waves. This work concludes illustrating the applicability of the model to study viscous resuspension phenomenon in a unsteady, falling suspension film. © 2012 American Institute of Chemical Engineers AIChE J, 58: 2601–2616, 2012