Design Optimization of Subcavitating Hydrofoils for America's Cup Class Yachts

This section is critical for the America's Cup. During races, a decrease in wind or a poor maneuver can result in a transition to displacement mode, severely impacting performance. In such scenarios, competitors may travel significantly slower, making it essential to maintain flight on the foils.

The upper range of the drag polar is particularly important for takeoff and maneuvering. A well-optimized polar can enhance either speed or range; for sailing vessels, the focus is primarily on speed. Conversely, for propelled craft, improvements can lead to increased range.

At the lower end of the drag polar, higher wind speeds can lead to cavitation, which limits top speed. We will discuss this limitation further. Our optimization process utilizes parameterized freeform deformation volumes, starting with a baseline foil shape from a previous year, which has already been fine-tuned and tested in competitive scenarios. Additionally, this foil design incorporates a flap that spans the entire length of the wing.