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Trifoiler Thesis

Greg Ketterman's 1983 California State Polytechnic University thesis "Design Modifications for a Model Hydrofoil Sailboat".

Analysis and mathematical model of a single-masted model of early Trifoiler concept. Includes velocity prediction program (VPP) source code in BASIC.

Used by permission from Greg Ketterman.

Polar Diagram

Narrative by Dan Ketterman that accompanied the polar diagram below as excerpted from email to User:Neuperg March 2006.

"This is my personal judgment of wind, boat speed, wind and boat angle to the wind, and wave conditions, myself, I weigh about 165 and my wife/crew, is about 130 lbs. These speeds are based on me driving. In looking at the polar diagram closer, my gut feeling is the boat speed is for a single pilot going to weather for both wind levels of 18-35 MPH. However, the diagram looks like it would support 2 people onboard for broadreaching in the wind range of 18-35 MPH. Therefore, I am saying that weight is less critical when sailing deep, because the center of gravity (CG) on a TriFoiler is aft upwind due to the drag in rigging, but the CG goes forward due to less rig drag aloft while broadreaching. More speed generates higher thrust vectors in a more forward direction."

File:TriFoiler Polar Diagram.jpg

TriFoiler Engineering or Performance Data Collected

Drag Curves

Foil Technology

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