Numerical simulation of the free-interface of a moving liquid jet by means of a VOF method

Numerical simulations of a two-dimensional gravitational liquid sheet injected in another immiscible fluid are performed by means of a home-made numerical code, named MultiFluids. Both steady and unsteady configurations are investigated. In the first part of the present paper, the steady shape of the liquid sheet has been computed by solving the two-dimensional Navier-Stokes equations for variable density incompressible flows and the interface between the two fluids has been determined by using a VOF method. The analysis takes into account viscous, inertial and gravitational forces. Velocity, pressure and shape of the sheet are investigated and the results are in well agreement with previous numerical and experimental results. In the second part of the work, the transient response of the planar liquid sheet, subject to deflection due to inertial forces, has been analysed. This kind of application constitutes a preliminary study within the framework of a wider investigation about a coating industrial process.