Systems Integration: V Foils andA-Frame Sails for the RAVE V

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

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 eliminatinghigh bending loads on aka

• Easy dock clearance

Retractable Foils

Foils are retractable to facilitateeasy launching from a beach andsimplify trailering

V FoilsTapered Section• Large cords at top to enable

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

is from the V foil, 30% fromLifting tube

• Cord tapers down and pitchdiminishes on lower foils toreduce lift and resistance athigh speeds– Less than 20% of the lift is

from the V foil, 80% fromlifting tube

Lower Foil

Whole V Foil Models

V FoilsFoils tipped with soniclifting tubes:• For efficient lift

production, 25% lowerdrag than equivalent Tfoil

• To reduce tip vortices onV foils

• To reduce cavitation at Vapex

Rudder foil• Rudder foil pitch

and lift controlledby pitch of boataround theforward foils

• Lower loads onrear foil

• V foil shape notneeded

Full LengthRudder Foil

Models• Sonic lifting tube is

25% lower drag thenthe equivalent T foil

• Sonic lifting tubeprovides higherlateral rudder forces– Improved rudder

efficiency in shallowwater

Drawing by Jacob Simon and Clayton Bader

• Helps to generate arighting moment

• Reduces the wingtip vortices fromthe sails

• Utilizes strength oftriangleseliminating sidestays

A Frame Rig

Why An A Frame

High Speed Loads Diagram

Low Speed Loads Diagram

Handicap Accessibility

Similar to WindRider modelWR17-AS (at right), RAVE Vwill also be handicapaccessible with the options forcustom foot and/or handcontrols. Hiking will not berequired.The total force needed tocontrol the boat is just 20 lbsor less for the handicap set up,and redundant controls go toeach 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 emptyweight)

• May utilize ballast tanks to compensate for changes increw weight

• The rudder is controlled by foot pedals leaving yourhands free to handle both sheets

• Sheets can move together or can be adjustedindividually for trimming the forces

• Price will be less than any comparable foiling boats

Conclusions

• Integrated systems solution of V foil with soniclifting 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