sail-world.com -- ORC announce Velocity Prediction Program improvements
ORC announce Velocity Prediction Program improvements
Wed, 7 Nov 2012
On the occasion of its 43rd Annual General Meeting, the Offshore Racing Congress (ORC) is happy to announce a major step forward in the accuracy of its Velocity Prediction Program (VPP) to be implemented for the 2013 sailing season. One of the principal aspects of this program, the Residuary Resistance (Rr) formulation, has been revised to now be more accurate for a broader range of yacht types that race within the ORC fleet database.
This new innovation is the result of an extensive multi-year study conducted by the International Technical Committee (ITC) in which historical data derived from tank test results has been combined with new research using Computational Fluid Dynamic (CFD) tools to create the new formulation.
'This is a huge step forward in solving a difficult problem which has faced VPP research for many years,' says Bruno Finzi, Chairman of ORC. 'The Congress applauds the ITC for the completion of this major project that will benefit all boats racing in the ORC fleets around the world.'
The new Rr formulation used in the new VPP is producing theoretical predictions which are much closer to the measured performance data taken from numerous boats in the ORC fleet.
'We looked at this carefully to help validate our results. The implied wind calculations are also much closer to that observed on the race course,' says Alessandro Nazareth, Chairman of ITC.
The Rr project's new formulation was the result of collating the relevant Delft Systematic data, analyzed by ITC member Kay Enno Brink and the CFD results coming from ITC's Philippe Pallu's work at CRAIN and the Fine-marine code work performed by new ITC member Jason Ker. Another ITC member working on this project was Andy Claughton of Southampton University.
'Validation of this new formulation has been very important to ensure that all elements of the fleet are treated fairly,' says Claughton. 'Our tests indicate that if any race from the past is rescored using the new rule the spread of corrected times for the first 10 or 15 boats is reduced, sometimes by 20-30%. This is fantastic progress.'
For more information on ORC's test fleet using the new 2013 VPP, visit the ORC website.
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