A key factor in most computational fluid dynamics (CFD) techniques is the grid that contains the representation and connectivity of the elements into which the domain has been subdivided. Unstructured anisotropic meshes present benefits due to the fact that they are more easily adapted and allow higher resolution to be focused only where it is required, so the mesh can be optimised to adequately resolve local features occurring during the solution of the physical problem. This paper examines how transient simulations of the drainage of liquid in flotation froths can be benefited from using adaptive remeshing. Fluidity, a general purpose finite element method code capable of using anisotropic mesh adaptivity, is used to accurately resolve the boundary layers present at the liquid-foam interface as well as other strong gradients that can develop during the drainage process. (C) 2011 Elsevier Ltd. All rights reserved.