Rave v presentation for foiling week (final) (1)

Systems Integration: V Foils and A-Frame Sails for the RAVE V

Presented by Larry Knauer, Lead Designer, WindRider International July 2, 2015 Lake Garda, Italy

© 2015 WindRider International


Base Design by Clayton Bader & Larry KnauerFoil design by Thomas Cusumano II

Stability and Structures by Jacob SimonProduction engineering Zachary Frederick

Production Technician Justin Ryan

Contributors

Then & Now

Original Rave 199842 knot Demonstrated

Rave V coming soonDesign speed 35 plus knots

http://www.windrider.com



1/6 Scale Model

Drawings By Clayton Bader

V Foils• Generate lift proportional to

submergence in the water• Lifting load shared by ama

and waka thus eliminating high bending loads on aka

• Easy dock clearance



Retractable Foils

Foils are retractable to facilitate easy launching from a beach and simplify trailering


V FoilsTapered Section• Large cords at top to enable

early takeoff at around 7 knots– 70% of the lift at low speed is

from the V foil, 30% from Lifting tube

• Cord tapers down and pitch diminishes on lower foils to reduce lift and resistance at high speeds– Less than 20% of the lift is from

the V foil, 80% from lifting tube

Lower Foil


Whole V Foil Models


V FoilsFoils tipped with sonic lifting tubes:• For efficient lift

production, 25% lower drag than equivalent T foil

• To reduce tip vortices on V foils

• To reduce cavitation at V apex


Rudder foil• Rudder foil pitch

and lift controlled by pitch of boat around the forward foils

• Lower loads on rear foil

• V foil shape not needed


Full Length Rudder Foil Models

• Sonic lifting tube is 25% lower drag then the equivalent T foil

• Sonic lifting tube provides higher lateral rudder forces– Improved rudder

efficiency in shallow water


Drawing by Jacob Simon and Clayton Bader

• Helps to generate a righting moment

• Reduces the wing tip vortices from the sails

• Utilizes strength of triangles eliminating side stays

A Frame Rig

Why An A Frame




High Speed Loads Diagram


Low Speed Loads Diagram

Handicap Accessibility

Similar to WindRider model WR17-AS (at right), RAVE V will also be handicap accessible with the options for custom foot and/or hand controls. Hiking will not be required. The total force needed to control the boat is just 20 lbs or less for the handicap set up, and redundant controls go to each seat.



Other Nice Features• Retractable pontoons will make trailering and launching the

boat from a ramp easier• It carries 2 people weighing a total of 400 lbs, with a max

boat weight of 700 lbs (300 lb boats empty weight)• May utilize ballast tanks to compensate for changes in crew

weight• The rudder is controlled by foot pedals leaving your hands

free to handle both sheets• Sheets can move together or can be adjusted individually for

trimming the forces• Price will be less than any comparable foiling boats


Conclusions

• Integrated systems solution of V foil with sonic lifting tube along with A frame sail rig:– Low structural weight– Higher sail forces– Self trimming for speed– User and handicap friendly– Simplified beaching and trailering– Low initial foiling speed– Reduced drag at high speed

Sports

Rave v presentation for foiling week (final) (1)