I believe you are correct, Lynn
There were a couple of fairly recent
developments that I thought held some promises in prop design, but they do not
appear to have panned out.
One was the “bi cambered” prop
blade which as best I recall was suppose to provide more thrust – I believe
it did lower the Prop noise somewhat, but the increased thrust does not seem to
have developed.
The vortex generators (of one type or
another) on the prop blades – the one most commonly seen were the dimpled
or holey tape. Again have not seen that recently
Then the one that looked to have the most promises
was the Lipps prop blade – narrow near the hub and tip and broad near the
mid section. I really seem to prove itself in racing – but have not
hear of it bring that apparent promise of improved performance to the common
crowd.
http://www.biplaneracing.com/files/Issue77_8-13.pdf
That about all I can recall recently
Ed
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Lynn Hanover
Sent: Saturday, March 06, 2010
8:32 AM
To: Rotary
motors in aircraft
Subject: [FlyRotary] The stalled
propeller blade
For those who would like to go further into the weeds on stalled
propeller blades, here is research on the wood propeller for the WWII Spitfire.
Note that only half power could be used during part of the take off
run, as the blades would stall otherwise.
Note also that the thicker Clark "Y" was better than the thin
bladed metal prop of the time.
The Clark "Y" ??? Have we nothing better in 60 years? There
is much work to do on propeller design. About 80% left to discover...........