schickler tagliapietra

Foil engineering developments. New applications on mono and

multi-hull sailing yachts

Overview •  Company Background •  Recent Projects •  Object of Foil Use •  Engineering Challenges •  Case Studies •  Future Work

Schickler Tagliapietra

•  Founded in 32nd America’s Cup •  Involved in 4x AC, 1x VOR •  Design and Engineering •  Simulation Based •  Beyond Structural Specialist

Recent/Current projects •  Gunboat G4 FEA, VPP, foil design •  Whites Dragons foiler •  Challenge Italia C class •  Mini 650 prototype •  Kuka Light •  Luna Rossa AC34 (external)

•  Luna Rossa AC35 (full time)

Object of foil use •  Trading wetted surface for induced drag, obviously

Object of foil use •  Moment influence

–  Roll –  Trim

Object of foil use •  Uncoupling (even reversing) force balance from e.g. roll

Object of foil use •  Trading wetted surface for induced drag •  Moment influence •  Uncoupling of force balance from vessel movement

Along with drag reduction, foiling can allow for decoupling of sail carrying power from e.g. heel angle, mass

Degrees of Freedom •  6 DOF VPP key to balancing trade-offs

surge, sway, heave, pitch, roll, yaw

•  Must be customizable for novel systems •  Must have user trim variables available to optimizer •  Allow for coupling trim variables to one another

Custom VPP best choice

Use confirms value of optimum control of otherwise unstable systems

Challenges in trim variables

•  Range of movement to the maximum possible •  Concentrated load carrying on foils •  Controllable and precise positioning and adjustment •  Loads passed to vessel via mechanical systems

This is where ST sets itself apart

Case study: Pegaso 60’ Before you Run, you have to walk…

5 DOF Keel System •  Canting •  Lifting •  Rotating bulb •  Pitch windward winglet •  Pitch leeward winglet

1. UPWIND full power

Case study: Pegaso 60’

Keel is on centerplane and bulb winglets are positioned parallel to the blade to maximize the lateral area. Each one is independently angled at an optimal angle with upper blade and strut generating high lift coefficient as slotted flaps

Case study: Pegaso 60’

2. UPWIND light air

Case study: Pegaso 60’

3. DOWNWIND VMG mode

Case Study: C – Class Design: PARAMETRIC MODELLING & OPTIMIZATION PROCESS

•  CANT RANGE : 28 ° •  RAKE RANGE : 10 ° •  YAW RANGE : 7 °

Daggerboard Control System

•  Spherical Surface Upper Bearing •  Flush Bottom Bearing

•  Rake Range: 10 ° •  Tilting •  One pin removal •  Stern with Recess •  Ball at the Bottom Bearing •  Partially Suspended

Rudder Blade – 25% under hull

Rudder Rake Control System

Rudder Rake Control System

Case study: Offshore monohull •  Lower power to weight ratios can gain from foiling

Glide Free Laser only confirms…

•  Trade-offs differ from catamarans, moth class •  Limit is engineering (or rules) •  Offshore canting keel yachts

–  Light IMOCA yachts –  Mini proto –  Similar other reaching boats

Mini 650    

Foils for trim control Already employed in Minis

Case study: Offshore monohull •  Lightweight canting keel yacht •  Add lift foil to existing straight dagger in existing case •  Effectively no limit from rules •  VPP study proves outboard stability generating foil helps

at higher speed, better than inboard foil as AC72 Combination of moment generation and drag reduction

•  Rake of dagger inadequate, need to use flap system

Foil Variations

Case study: Offshore monohull Conflicting High and Low pressure sides

•  Offset foils longitudinally •  Introduce fence •  Swept foil to position lift •  Need to house mechanism •  Acute dihedral

Case study: Offshore monohull

Case study: Offshore monohull

Case study: Offshore monohull

Case study: Offshore monohull Challenges met with solutions

•  Foil and flap aircraft influenced •  Flap angle through 30 deg, swept •  Spline and drive allows for adjustment •  Dihedral can be modified up to 10 deg, exchanging parts •  Full craft weight can be carried on foil/flap •  Sealed housing to maintain lubrication

Future work •  Ultralight foiling transportable catamaran

–  Compotech Inflatable Technology –  Low cost –  True beach cat

Future Work •  Bonezzi Moth

–  New design based on novel experimentation –  Made in Italy

Thank you for your attention!

Special mention to: Massimo de Luca Peppe Musca Vieri Abolaffio Andrea Vergombello Antoine Coadou Federico Patti