Integrated CFD–optimization workflow for the hydrodynamic and aerodynamic development of AC75 foiling yachts

The hydrodynamic and aerodynamic development of an AC75 foiling yacht requires an integrated approach that combines advanced CFD simulations, optimization techniques, and data analysis tools. In this context, the use of a multi-objective optimization software such as ESTECO modeFRONTIER — supported by the construction of high fidelity surrogate models — enables efficient exploration of the complex design spaces typical of modern foiling configurations. The primary goal is to accelerate decision making and make efficient use of CFD simulations while maintaining high predictive accuracy.
Examples of integrated workflows can be found both in hydrodynamics and aerodynamics. In hydrodynamics, the workflow focuses mainly on the design of 2D foil sections. Automated generation of families of profiles for direct multi-objective optimization, combined with adaptive sampling techniques and surrogate models such as Gaussian Processes and Radial Basis Functions, allows rapid identification of configurations that achieve an optimal compromise between lift, drag, and stability. The resulting response surfaces enable detailed sensitivity analyses and support the selection of the most promising sections for subsequent 3D validation.
For strongly 3D configurations, a workflow based on DOE and RSM is implemented, performing pure parametric shape optimization and leveraging the software as an engine for surrogate model generation and response surface based optimization. This approach makes it possible to explore numerous geometric configurations with significant time savings while preserving consistency and accuracy with CFD results.
On the aerodynamic side, reduced order models allow efficient representation of the sail–hull system behavior, also accounting for the influence of crew positioning on overall balance. Through extensive parametric studies, it becomes possible to quantify performance sensitivity to crew movements, optimizing operating configurations and dynamic onboard strategies.
The entire workflow enables reduced development time while enhancing the quality and robustness of design solutions—key factors in the competitiveness of AC75 yacht.