Konstantin I. Matveev
Washington State University, Pullman, WA 99164, USA
Unmanned aerial vehicles that can operate in both air and water represent an interesting but challenging engineering development. This study aims at conducting high-fidelity computational fluid dynamics modeling of a simple propeller in hovering modes in the unbounded air and water media and near the air-water interface. The volume-of-fluid method and the overset meshing methodology are utilized to simulate a rotating propeller in multiphase environment. The mesh-verification was carried out to establish suitable characteristics for a numerical grid. In the parametric study, the main variable parameter was the vertical position of the propeller with respect to the air-water interface. It was found that at a given averaged torque, thrust values of a propeller far above or far below the air-water interface were similar, while the rotational speed in the air is much higher. Close to the air-water interface, thrust increases reaching maximum when the propeller operates slightly above the undisturbed water level. Large oscillations in the thrust and complex unsteady surface flow exist when the propeller is positioned right at the water level. The obtained results and the simulation approach can benefit practitioners developing multi-domain unmanned vehicles.