Numerical modeling of gas-jet wiping process

The proposed study focuses on the numerical modeling of the gas-jet wiping process, which is used to control the coating thickness applied on a solid substrate in various industrial processes. In the galvanization of steel strips, a turbulent slot jet is used to wipe the coating film dragged by a moving steel substrate after dipping in a liquid zinc bath. In the present study a numerical modeling approach of the process is presented using the VOF method for multiphase flows coupled with LES turbulence modeling. Simulations are carried out with three different codes, namely Fluent, OpenFOAM and the research code Thetis. A set of wiping conditions is selected to match a laboratory experiment on a dedicated setup, comparing the numerical results with the experimental data. In a case where the experimental value of the final to initial film thickness is 0.22, Fluent and OpenFOAM overestimate it predicting 0.36 and 0.31 respectively, while Thetis with 0.13 underestimates it. Thetis predicts the closest value to the experiments for the wave amplitude and OpenFOAM for the wavelength. A discussion of the observed differences in the results points out the best modeling practices for the jet wiping process.