Improved Hydrofoil Performance Measurement Method in SSPA towing tank

Forskningsprojekt, 2024 – 2025

Foiling crafts are gaining popularity due to their advance performance and minimal energy consumption which makes them perfect candidate for using in electric propulsion solutions. In some previous research projects, we measured hydrofoil performance in SSPA’s testing facility. Performed tests included simple lift and drag measurements of single foil in towing tank, Fluid-structure interaction studies in cavitation tunnel, and foiling model boats for master thesis and testing the surface tracking sonar sensor in towing tank.

Since the standard setup for towing tank test is built for captive and free motion of hull, in all the above-mentioned projects, we had to improvise new settings and test rigs. This made the performed tests much more expensive than initially intended and/or sacrificed the accuracy of the measurement.

On the other hand, the routine scaling procedure based on Froude number is applicable for displacement hulls and not necessarily suitable for hydrofoil. Whilst free-surface interaction with foil is scaled with Froude number, Reynold’s number scaling is very important for studying hydrofoil’s lift and drag. The idea of performing model tests based on Reynold’s number scaling and correcting the results for free-surface interaction is plausible (opposite of ITTC method).

In this project, we propose to layout a method and testing setup to measure performance of a hydrofoil. Tests will be performed in SSPA’s towing tank and focuses on different aspect of foil performance including the motion of foil during test, interaction of foil and free-surface and foil roughness effect. Design of the test also includes dynamic monitoring of the foil’s real angle of attack since it is the major source of the measurement uncertainty.

The project will be a close collaboration between RISE Maritime department and Chalmers University.