On 13 Aug 2004 14:10:13 -0500, Todd Pattist
wrote:

It's that and the fact that you can't keep on increasing the
prop diameter - you run out of ground clearance, exceed
material limits or hit the inefficiencies of supersonic
tips.

As I mentioned, that's why the prop designer came up with such a
strange looking planform. The prop is wide where it's most efficient
(aproximately halfway out from the hub where the prop speed is way
below sonic speed) and can produce the greatest thrust, then narrows
down rapidly from that point from both leading and trailing edges,
then the leading and trailing edges get to running roughly parallel
before they stop abruptly at the tip which is squared off.

As I mentioned, since the tip is moving the fastest, it's smart to
present very little for the air to get draggy about at that point.

Some props have rather wide tips, which get hugely draggy at high
rpms, and also produce a lot of noise.

This things is very odd looking but produces good thrust while being
quieter than most props.

Corky Scott