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

The final condition we are examining pertains to maneuvering. This scenario involves a reduction in speed while simultaneously requiring a high lift for turning, particularly when additional lift is necessary to counteract side forces. To achieve this, a relatively high lift coefficient (CL) of approximately 1.3 is required.

Now, let us focus on the optimization process. We are plotting the airfoil shape alongside varying flap angles. While the airfoil shapes remain consistent, the flap angles differ across each condition.

In the plot, the line representing the maximum coefficient of pressure (CP) is currently being exceeded in almost all conditions, particularly in the maneuvering scenario. An accompanying animation illustrates the CP behavior, which fluctuates before stabilizing beneath the maximum CP line. Although there is a slight increase in drag, the initial design failed to meet the cavitation constraints, resulting in a net gain in performance.