SailGrib WR comes with the iPolar module developed by KND for iOS. (Paid version or Premium option only).
KND is a world leader in sailing performance ananlysis with over 15 years of experience in the field of speed prediction programs (VPP) for racing yachts.
We thank Dimitri Nicolopoulos-Salle, founder of KND, for giving us access to the iPolar code.
iPolar computes the performance polars of a given boat as a function of a reduced set of parameters:
Length Overall (LOA)
Waterline Length (LWL) if unknown, iPolar will make the assumption that LWL is 95% of LOA
Displacement
MainSail Area
Jib Area
Symmetrical spinnaker area (optional)
Asymmetrical spinnaker area(optional)
Limitations of iPolar:
Currently only handles monohulls
LOA ranging from 8 to 20m
Accuracy:
iPolar is a very simple Velocity Prediction Program (VPP) which predicts the polars of a boat based on a very limited range of parameters: length, displacement and sail area .
This simplicity implies some restrictions : iPolar is meant to predict reasonably accurately polars for production cruisers and cruiser racers - it is currently limited to mono-hulls.
For boats significantly outside of the iPolar parameter range and for racing polars accuracy, the use of more complex VPP tools is required. KND-SailingPerformance uses the NorthSails VPP, developed through several cycles of America’s Cup, relying for each boat on the generation of a large matrix of hydrodynamic forces (through Computational Fluid Dynamics or CFD methods) and advanced sails models. In case you would be interested in such a VPP for your yacht, contact us directly.