Boat Propeller Cavitation

Description

This project uses ANSYS Fluent to simulate boat propeller cavitation, applying the Mixture multiphase model to a critical phenomenon in marine propulsion engineering. Cavitation occurs when localized low pressure on the propeller blades causes water to vaporize, forming bubbles that collapse and erode blade surfaces while degrading propulsion efficiency. This simulation captures how cavitation forms and evolves around a rotating propeller, a key concern in naval architecture and propeller design.

Methodology

The propeller geometry is built in DesignModeler and meshed in ANSYS Meshing using an unstructured grid suited to the rotating fluid domain. The Mixture model is configured with the Schnerr-Sauer cavitation model to simulate water-vapor phase change, with appropriate vaporization pressure limits set to capture cavitation onset. Mesh motion is implemented to represent propeller rotation, paired with the SST k-omega turbulence model for accurate external flow resolution, and the analysis is run transient to capture the time-dependent development of cavitation, including super-cavitation at high rotational speeds.

Conclusion

Results include vapor volume fraction distributions on the propeller surfaces, pressure fields showing where cavitation initiates and grows, and the relationship between rotational speed and cavitation extent. These findings directly inform propeller design optimization — blade geometry, material selection, and operating speed — to reduce cavitation-driven erosion, noise, and vibration, supporting more efficient and durable marine propulsion systems.