Simulations of an Air-Ventilated Strut Crossing Water Surface at Variable Yaw Angles

Hydrodynamic devices intended to produce lift, control actions, or propulsion can be prone to air ventilation when operating near the free water surface. The atmospheric air may propagate to the low-pressure zones around these devices located under the nominal water level. This often leads to performance degradation of hydrodynamic systems. Modeling of air-ventilated flows is challenging due to complex flow nature and many factors in play. In this study, the computational fluid dynamics simulations are carried out for a surface-piercing strut at different yaw angles. At small yaw angles, the strut underwater surfaces remain wetted, whereas at large yaw and sufficiently high Froude numbers the suction side becomes air ventilated. At the intermediate yaw angles, both wetted and ventilated flow regimes are possible, and the existence of a specific state depends on the history of the process. The present computational results demonstrate good agreement with available experimental data.