A Numerical Analysis of the Behavior of Liquid Film Between Counter-Rotating Rigid and Deformable Rolls

It is important to accurately predict the behavior of liquid film between the rotating rigid and deformable rolls in the film coating process of steel and paper industry. The behavior of liquid film between rolls with the negative gap due to the press contact is determined by the interaction between solid rolls and liquid passing between rolls. In the present study, the numerical methodology for the prediction of behavior of solid rolls and liquid film was introduced with the CFD and FEM analysis. The shape of a deformable roll rotating in press contact with a rigid roll was obtained numerically from the FEM simulation. Based on the results of deformed roll shape, the CFD simulation on the liquid flow between rolls was performed with an arbitrary gap between rolls in the contact area. By comparing the pressure distribution of liquid passing through the gap with the contact pressure distribution of solid rolls, the liquid film thickness between rolls was obtained in equilibrium with the pressure between the rolls. From the CFD simulation on two phase flow of liquid film around rotating rolls with the thickness and flow rate of liquid film passing through the contact area, the thickness of liquid film bifurcated along rolls were predicted for various rotating speed.