Nobody will deny the importance of validating the numerical predictions with good quality physical models.
Cape Horn Engineering has been validating its simulations since the early years of using RANSE solvers for marine applications. Like most marine CFD programs, the first validations of our simulations were for the Wigley and Series 60 benchmarks back in 1997-1998. These were followed by other cases more relevant to the industry, as shown in the list below. When validating these methods, the focus was not only on the forces, mainly resistance, but also on the dynamic sailing attitude (sinkage, trim, squat), and on the predicted motions for ships in regular waves.
A few years later, our simulations were extensively validated during the 32nd America’s Cup campaign with challenger BMW Oracle Racing. Validation was done using more than 20 large models towed at the Institute for Ocean Technology in Canada, one of the most prestigious towing tanks for America’s Cup Class yachts. The accuracy and benefits of the simulations were demonstrated so thoroughly that it was decided to cancel the last model tests of that campaign. The last extensive validation took place recently within the framework of the Wide Light Project from the Sailing Yacht Research Foundation. It consisted of a validation based on a 120 points matrix for a typical modern sailing yacht, fully appended and in different sailing condition. The comparison showed a very good correlation of our results with the tank data.
Today, we see a trend towards validating the CFD performance predictions directly against the full-scale ship trials instead of with model testing. Our latest validations were of this type.
- Full scale numerical sea trial prediction for Fleming 58 yacht, sea trial data from Wright & Sons Pty Australia and Towing Tank report from Australina Maritime College, blind validation performed in 2019
- Full scale numerical sea trial prediction for cargo vessel REGAL, Proceedings 2016 Workshop on Ship Scale Hydrodynamic Computer Simulation, Lloyd’s Register, validation in 2018-2019
- Comprehensive ‘blind’ CFD validation of calm water performance for a Wide and Light modern yacht with tests performed by the Wolfson Unit at the QinetiQ towing tank in Gosport England : 2014
- Calm water performance of America Cup Class AC90 for Team Origin, 2 models tested by Wolfson Unit at the Southampton Solent University Towing Tank : 2008
- Calm water performance of America’s Cup Class yachts for the 32nd AC Challenger BMW Oracle Racing, extensive validation with tests at the Institute for Ocean Technology (IOT) in Canada : 2003-2007
- Calm water performance of Volvo Ocean Race Open 70 yachts for the ABN Amro Racing team, validated against tests at MARIN in The Netherlands and the Wolfson Unit in Southampton : 2004
- Resistance and motions in regular waves for a Littoral Combat Ship model, validated against tests at the Hamburg Model Basin (HSVA) : 2003
- Resistance prediction and motions in head waves (jumps) of a planing hull for speeds of up to Fn=4, validated against test at the Osaka Prefecture University in Japan, and against other numerical methods : 2001
- 2D asymmetric drop tests with a wedge (slamming), validated against tests at Coastal Systems Station (CSS) in the USA : 1999
- Breaking waves ahead of the bow of a very fat ship model, validated against tests at The Ship Research Institute (SRI) in Japan : 1999
- Resistance, sinkage and trim of Series 60 hull, validated against tests at University of Iowa and other numerical codes at workshops : 1998
- Resistance, sinkage and trim of Wigley hull, validated against tests at The Ship Research Institute (SRI) in Japan and other numerical codes at workshops : 1997
Check our Publications for more complete information about CFD validation