Wake Survey of a Yacht Keel for CFD Validation and Flow Analysis1

Abstract The wake behind an America’s Cup keel model is studied experimentally and numerically. A RANS code is validated against the data from wind tunnel tests with generally good agreement. The wake measurements are also used for analysing the flow case. Differences in the performance of design alternatives are explained by studying the wake. Force-estimates based on wake integration methods applied to the computed wake are proven to be equally or slightly less accurate than integration of surface forces. The drag force is decomposed by applying wake integration methods to the computed wake. The result is compared with the drag components computed with a potential flow/boundary layer code. The comparison points out the difference between vortex drag and induced drag. Finally, the measured wake is used to validate the lift distribution along the winglets computed with a RANS code and a potential flow code.