From: "Luis" <pegaso25 en teleline.es>
Reply-To: escepticos en ccdis.dis.ulpgc.es
To: <escepticos en ccdis.dis.ulpgc.es>
Subject: Re: [escepticos] autogiros ultraligeros
Date: Tue, 26 Mar 2002 00:47:58 +0100
Hola Javier, no sé como lo harán los de ahora, pero te transcribo lo que
leo:
One of the problems with Cierva's three designs up to this point was
that
the rotor was rigid. This created two problems. First was that it created
a
gyroscopic effect. As soon as the aircraft tried to move, this effect
would
cause the aircraft to tilt. The other problem came from unbalanced lift.
As
the rotor was spinning, one side would be moving the same way the aircraft
was moving, increasing the relative wind speed, while the other side would
be moving opposite the direction the aircraft was moving, decreasing the
relative wind speed. The side with the higher relative wind speed would
have
a higher lift than the side with lower relative wind speed, causing the
aircraft to tilt. Cierva came up with a solution to this problem while
watching an opera. One of the props for the opera was a windmill with
hinged
blades. Cierva decided to use hinges in his rotor designs. This allowed
the
blades to rise and fall depending on what direction they were moving in.
The
blades moving with the aircraft rose because of the higher lift, but this
also served to decrease the speed at which they were moving through the
air.
The blades traveling in the opposite direction of they autogyro would fall
because of the lower lift, but this would serve to increase their air
speed.
The combination of the rising and falling action, which came to be known
as
flapping, and the increase and decease this had on the relative wind
speeds
served to balance the lifts created on each side of the aircraft. The
hinged
blades also eliminated the gyroscopic effect caused by the rigid
blades.....//....
(más adelante en la misma lectura)
...//... The next major advance in autogyros came on August 5, 1931. This
was the first flight of the Wilford WRK. This new autogyro replaced the
hinged rotors with a rigid rotor with cyclic pitch variation. Cyclic pitch
variation is a method where the pitch of the blades is changed as they
spin.
The pitch is lowered when they are moving in the direction of the
aircraft,
and raised when they are moving in the opposite direction. This does the
same thing as flapping to balance the lift created by the blades. The WRK
was the first autogyro to successfully fly with a rigid rotor.
más para ser leido en http://www.angelfire.com/home/lewis/autogyros.html
Un saludo.
Luis