NORTH VPP™ ...predicts sail/rig performance
HULL VPP™ ...integrates sail/rig forces with forces on hull and appendages

North’s VPP and Hull VPP are powerful new tools that allow hull/appendage data to be integrated with rig/sail models, giving designers the ability to analyze an entire sailboat, from masthead to the tip of the keel, as a single working system. Both programs use sophisticated CFD modeling to develop reliable hydrodynamic hull data without tank testing.

Hull VPP can be used to create a set of hydrodynamic forces for a specific hull & appendages, then feeds this information directly to North’s VPP. This is accomplished by providing Hull VPP information as an IGS file (3D surface file of the canoe body and appendages).

Once hydrodynamic forces are established for a specific hull, aerodynamic sail data for the same boat’s rig are generated by Flow & Membrain (and now the VWT) and then integrated into the VPP process.

All upwind aerodynamic sail forces are derived from a specific yacht’s custom sail designs as predicted by Flow/Membrain, as opposed to generic sail force coefficient’s used in other VPP processes. Reaching and downwind cases have the option to use specific sail force coefficients developed through North’s Virtual Wind Tunnel runs, or with custom coefficients that would be developed with the VWT.

In addition, North VPP can be used to optimize sail shape and/or sizes to suit a rating rule or a specified set of wind and sea conditions.

As a result, upwind sails refinements can be tailored to the specific boats characteristic and downwind sail codes and areas can be chosen based on specific goals. These tools represent a significant technological leap forward, allowing North to accurately tailor sails for any boat and introduce design advances to a broader spectrum of clients. No other sailmaker can even come close.
Blue dots in charts represent measured on-the-water performance data from TP52 Platoon in all races she won in 2008 MedCup. The black dots are North Sails VPP predicted performance.© North Sails
Predicted sail crossovers used to refine sail shapes to match a particular boat’s performance characteristics.© North Sails