comparison polarity charts twin keel vs monokeel

[Seajet]

The chord of a foil is section thickness compared to length - thick chord a stubby high drag 'design' - ( think Snapdragon etc ) narrow chord is a thin job.

Another example is a Starfighter jet wing is very narrow chord, a junkers 52 transport is thick chord.

Aircraft generally use flaps to increase chord at low speed, but not many boats do this ! Has been tried of course.

 

[Skysail]

I know Wiki is not always right, but in this case I think it is:

http://en.wikipedia.org/wiki/Chord_(aircraft)

Flaps generally increase camber, though extending flaps can increase chord too.

 

[bbg]

The chord of a foil is section thickness compared to length - thick chord a stubby high drag 'design' - ( think Snapdragon etc ) narrow chord is a thin job.

Another example is a Starfighter jet wing is very narrow chord, a junkers 52 transport is thick chord.

Aircraft generally use flaps to increase chord at low speed, but not many boats do this ! Has been tried of course.

Don't quite know what you mean. On a keel, the chord measurement is from the front of the keel to the back of the keel. It has nothing to do with the width of the keel. Chord can be short or long.

The width or thickness of the keel (from one side of the keel to the other e.g. from the starboard to port side) could be described as narrow or thick.

In the photo below, the keels have a chord length of about 30-40 cm, with a thickness of a few cm.

I thought that on airplanes the flaps primarily increase camber. Certainly the front flaps don't increase the chord length very much, while the rear flaps increase both camber and chord.

 

[bignick]

I thought that on airplanes the flaps primarily increase camber. Certainly the front flaps don't increase the chord length very much, while the rear flaps increase both camber and chord.

All correct except that "front flaps" are actually called leading edge slats.

 

[bignick]

For correct terminoogy see here:

http://en.wikipedia.org/wiki/NACA_airfoil