PHIL'S FOILS PAGE

I've gone pro and moved to a new location. Your browser should automatically take you there in 5 seconds. If it doesn't, please go to philsfoils.com.
Here's a sample from my Design Tips page on the above site:

Common Subjects

Rudders

Centerboards

 


Common Subjects

Terminology

Planform

First of all, the obvious: the planform you design must fit within your fleet's class rules.  Some fleets offer complete freedom in this, while others may force you to fit within a few mm tolerance of their official dimensions.

The simplest planform is the simple rectangle, and will give good performance while also being easy to fabricate.

A performance increase can be had by going with an elliptical tip - this can be done with either an elliptical leading edge or trailing edge while keeping the opposite edge straight (or the tip can be fully elliptical).  The performance increase comes from the increased lift and reduced drag from this shape - with a rectangular tip, water can 'escape' by going around the bottom of the foil rather than across the chord, while with an ellipse** its always a shorter path across the chord than it is around the bottom.