This paper focuses on the implementation, validation and exploitation of a vertical dropshaft flow operation using the commercial VOF-based Computational Fluid Dynamics (CFD) code, FLOW-3D ® . Using the experimental data of Chanson (2002), the package was used to simulate the flow patterns in a rectangular dropshaft with plunge-flow pattern. Both k−ε and k−ε RNG turbulence closures were tested ...