FIDAP is a Finite Element Code which solves the fully Navier Stokes equations. The program enables the possibility to incorporate or to specify own boundary conditions.

FIDAP is qualified to calculate flow problems with free surfaces.

We used FIDAP to calculate the reorientation behavior of a free liquid interface in a partly filled right circular cylinder upon step reduction in gravity.

The intention to describe the fluid motion encounters the difficulty modelling the moving contact line problem. The stress singularity has to be removed and a model for the dynamic contact angle has to be defined. In the numerical simulations the Navier slip boundary condition and a model for the dynamic contact angle are used. We achieved very good agreement with experimental data.