Experimental flutter testing of a low mass ratio NACA-16012 hydrofoil model

The steep increase in sailing speed experienced in the last decades, led yacht engineering to face fluid elastic instabilities issues resulting from the interaction of a light structure with the surrounding fluid flow at high speed. In this context, the authors of this paper decided to undertake an experimental campaign to test for flutter instability a low mass ratio hydrofoil model in CNR-INM water tank in Rome. The model is built as a segmented body to avoid structural participation of the components: this choice make the results prone to be employed for validation of reduced-order analytical or numerical models. The employed method, the final set-up and the testing procedure of the experimental campaign are detailed and the obtained measurements are presented and discussed. Beside the experimental campaign, the authors implemented an analytical reduce-order model to predict the flutter instability limit speed synthetizing the structure as a 2D spring-damper-mass system, and calculating the unsteadiness of the fluid loads generation by means of Theodorsen theory.