Numerical simulation of film instability over a corrugated sheet

The evolution of a liquid layer flowing down a corrugated sheet driven by gravity, which is the characteristic configuration of structured packing, is numerically analysed via the solution of the governing lubrication equation, which reduces the 3D physical problem to a 2D mathematical problem. Disjoining pressure is used to model contact line dynamics and surface wettability, while full implementation of capillary pressure allows to investigate contact angles up to 60°. The effect of corrugation is introduced via the definition, in the governing lubrication equation, of non-uniform gravity acceleration. Furthermore, the additional capillary force, arising from variations in the solid surface curvature, is also implemented. Different corrugation geometries and flow conditions, the latter being defined by the reference film Capillary number, are investigated, looking for configurations that allow enhancement of the liquid-gas interface area at low liquid flow rate. Such an analysis provides a novel approach in the design of structured packing, widely used in carbon capture via chemical absorption.