Analysis of multi-layer slot coating using NEKTON

The flow in a two-layer slot coater is studied using the commercially-available software package, NEKTON from Fluent Inc. The two fluids are treated as immiscible with no surface tension on the fluid/fluid interface. NEKTON uses quadratic finite elements as well as high-order spectral elements to discretize the flow domain. The position and shape of the free surfaces and interlayer are predicted. by means of an elastically-deforming mesh. It is found that the use of a segregated (Picard) solver enhances the robustness of the solution when the location of the fluid/fluid interface is not well-known. For fast convergence once a good initial condition is established, a coupled (Newton) velocity-pressure-geometry solver is used. The first solution is then parameterized as a ''template'', which allows for easily conducting further parametric studies. Results are compared with published experimental data and other numerical solutions.