A-Class Catamaran Boards



Presentation at The Foiling Week on A-Class Catamaran boards. See Day 2 streaming video to watch the presentation.







Sections for Proa Boards and Rudders



Design of three families of sections for shunting proas.  These sections have fore-aft symmetry and rounded edges.  Complete coordinates and XFOIL computed data are presented.





Sections for Sailing Hydrofoils


Design approaches and typical results for hydrofoils which must operate at low Reynolds numbers (small chord lengths and low speeds), as well as avoid cavitation at high speed.


Optimum Planforms


Design Tools




Chapter 1 Cavitation Inception on Foils, Struts and Pods

Chapter 2 Choice of Foil System for Optimal Performance

Chapter 3 Ventilation Inception of Surface Piercing and Submerged Foils and Struts

Chapter 4 Trim, Altitude and Pre-Takeoff Resistance of Hydrofoil Craft

Chapter 5 Longitudinal Stability (Controls Fixed)


Hydrodynamics of Hydrofoil Craft
Subcavitating Hydrofoil Systems

Technical Report 463-1
Hydronautics Incorporated

This is the most comprehensive reference on hydrofoil design I've found. It presents the engineering relationships and typical results for all aspects of hydrofoil design, covering both fully submerged and surface piercing foils.

These PDF files are no longer available online.  They can be found on the AMV CD-ROM #1 from the International Hydrofoil Society.




Generic Hydrofoil Analysis


A simple analysis of hydrofoil performance and comparison with test data. Included are comparisons with Alexander Graham Bell's HD-4 full scale test data and Hanno Smits' tow tank data. The approximate analysis is also applied to fully submerged T foils and surface-piercing V foils and ladder foils.

The lessons learned are:
- The simple analysis is adequate to predict the most important influences on hydrofoil performance. - Fully submerged foils are the most efficient for a given design point.
- Surface-piercing foils can be competitive with fully submerged foils when the requirement is to operate over a wide range of speeds.
- Pitch trim is vitally important to the performance of surface-piercing foils, especially V foils which vary their span as well as their area as a function of their depth of submergence.

I am deeply indebted to Hanno Smits and to the Bell estate for their generous permission to use their data in my analysis.





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