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

This analysis is crucial for the America's Cup races. When the wind decreases or a poor maneuver causes a boat to enter displacement mode, its performance significantly declines, while competitors may continue at much higher speeds. Therefore, it is essential to achieve and maintain flight on the foils for optimal performance, particularly during takeoff and maneuvering.

The mid-range performance is important for achieving either greater speed or range, depending on the type of vessel. For sailing boats, the focus is primarily on speed, while for propelled crafts, the emphasis can shift towards maximizing range. At the lower end of the performance spectrum, higher wind speeds can lead to limitations caused by cavitation, which restricts top speed.

Our optimization process utilizes parameterized freeform deformation volumes. We began with a baseline foil design from a previous year, which has been refined and tested in competitive conditions. Additionally, this foil features a flap that spans its entire length, which can be adjusted to an optimal setting based on varying conditions. This flap adjustment is a critical design variable that enhances performance across different scenarios.

Furthermore, we must consider cavitation, which occurs when pressure drops below vapor pressure, resulting in the formation of air bubbles. Understanding and managing this phenomenon is vital for maximizing speed and performance.