Investigation of Ship Airwakes Using a Hybrid Computational Methodology

The simple frigate shape geometry (SFS2) has been studied in free-air and wind tunnel environments for both headwind and yawed flow configurations. The ability of an unsteady Reynolds-Averaged Navier-Stokes (URANS) solver and a URANS/Vorticity Transport hybrid computational methodology to capture the bluff body wake characteristics has been assessed. Comparisons have been made with two different SFS2 experimental data sets, including new data from the Naval Surface Warfare Center Carderock Division. Overall good agreement between the hybrid and traditional URANS approaches was observed. Complex wake interactions were captured by the computational methodologies, and they have been assessed to provide insight into differences between the computational and experiment results. The influence of the unsteady vortex shedding from the bluff hangar has been characterized with respect to the changes in the flow field at hangar height and along the landing deck.