Propellors vs Rotors

wright1902glider wrote:

GET BACK IN THERE! 'YA DAMN WORMS!

Hi Harry,
snipped in places...


Wilbur and Orville used the largest props that would fit on their
airframe. In 1903 those were 8' 6" each and turned between 300 and 350
rpm depending on how hot the engine was. At an average of 8.56hp (the
engine only made 11.78hp for a few seconds dead cold), the twin props
produced an average of 96 lbs of thrust. or 11.22 lbs of thrust per hp.
Not bad on the first try.

96 pounds of thrust from 11 horse?

What did that whole rig weigh?



what happens. Hmmmmmmm. What's holding that paper up? All of the air
that it, the sheet of paper, is throwing downward, all on its own,
because it instinctually "knows" that this is the correct behavior for
good little sheets of paper that get blown on? Hold your other hand
under the paper as you blow. Any air moving downward? And what's the
paper doing? Hmmm?

But you Cheated!

Very localized pressure field resulted above the paper, and so what?

You sped up the air above the paper by blowing it.
(cheater)



BTW, addressing my previous statement about AOA, some planes can
definately climb nose-down in upright flight. Amazing, but the B-52 is
one of them. I was reminded of this 2 days ago while watching the
Hitler Channel. Looks goofier than hell.

BIG Lift Fairies!

snipped in places...
--------------and snipped some more-----------


Wilbur and Orville used the largest props that would fit on their
airframe. In 1903 those were 8' 6" each and turned between 300 and 350
rpm depending on how hot the engine was. At an average of 8.56hp (the
engine only made 11.78hp for a few seconds dead cold), the twin props
produced an average of 96 lbs of thrust. or 11.22 lbs of thrust per hp.
Not bad on the first try.

96 pounds of thrust from 11 horse?

Actually from the 8+ horsepower. Based on 1 horsepower = 1 pound of thrust
at 315 knots, the figure sounds like a reasonable static thrust value. The
thrust may have been a little less in flight.

What did that whole rig weigh?


I vaguely remember reading something like 600 pounds, plus the pilot of
course. Orville and Wilbur were both small and slight, so the gross weight
was probably only a little more than 700 pounds...

Peter Dohm wrote:

snipped in places...

--------------and snipped some more-----------

Wilbur and Orville used the largest props that would fit on their
airframe. In 1903 those were 8' 6" each and turned between 300 and 350
rpm depending on how hot the engine was. At an average of 8.56hp (the
engine only made 11.78hp for a few seconds dead cold), the twin props
produced an average of 96 lbs of thrust. or 11.22 lbs of thrust per hp.
Not bad on the first try.

96 pounds of thrust from 11 horse?


Actually from the 8+ horsepower. Based on 1 horsepower = 1 pound of thrust
at 315 knots, the figure sounds like a reasonable static thrust value. The
thrust may have been a little less in flight.


What did that whole rig weigh?



I vaguely remember reading something like 600 pounds, plus the pilot of
course. Orville and Wilbur were both small and slight, so the gross weight
was probably only a little more than 700 pounds...



700 lbs / 96 thrust = .137 - which is a wee bit below the .20 rule of thumb.

Might consider catapult launch?

"Richard Lamb" wrote in message
link.net...
Peter Dohm wrote:

snipped in places...

--------------and snipped some more-----------

Wilbur and Orville used the largest props that would fit on their
airframe. In 1903 those were 8' 6" each and turned between 300 and 350
rpm depending on how hot the engine was. At an average of 8.56hp (the
engine only made 11.78hp for a few seconds dead cold), the twin props
produced an average of 96 lbs of thrust. or 11.22 lbs of thrust per hp.
Not bad on the first try.

96 pounds of thrust from 11 horse?


Actually from the 8+ horsepower. Based on 1 horsepower = 1 pound of
thrust
at 315 knots, the figure sounds like a reasonable static thrust value.
The
thrust may have been a little less in flight.


What did that whole rig weigh?



I vaguely remember reading something like 600 pounds, plus the pilot of
course. Orville and Wilbur were both small and slight, so the gross
weight
was probably only a little more than 700 pounds...



700 lbs / 96 thrust = .137 - which is a wee bit below the .20 rule of
thumb.

Might consider catapult launch?


In a way, they almost did--sending it down a greased slide....

Remember that they had nearly 12 HP when first started--which gave them a
decent start slightly down hill and into the wind. All in all, I agree that
the whole enterprise was a little crazy. I am glad they succeeded, and
further engine development must have followed quickly.