Every minor improvement can have a major effect: thanks to aerodynamic optimizations, BMW vehicles are constantly becoming more efficient, while the performance of AC catamarans is ever increasing. To achieve this, turbulence and wakes in the airflow are analysed in detail. The CFD method is more precise than wind tunnel tests, as it makes it possible to analyse every detail of the airflow.
Particular focus is placed on the cross struts on the hulls, which are among the few components, whose form is not specified in the regulations. The positions of the crewmembers can also be optimised, as can the connection between the sail and the hull. The differences in pressure on the wing sail generate turbulence, which can be optimised.
CFD is used to test how effective detailed modifications are: how big is the effect? How do they affect the complex aerodynamic interaction between the platform, wing sail and positioning of the crew on board? Comprehensive data collection is also necessary, as any nuance can be crucial.