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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 • 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
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
• 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
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
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
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 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
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