Blade Flyer
Transition
The "Blade Flyer" is the hub, blades, engines and
vanes, exclusive of
any payload. The "vehicle" is the combination of a Blade
Flyer and its payload with or without an equipment module or payload
orientation device.
The blades freely rotate about their quarter chord axle. There are no
actuators between the hub and blades. The blade
flaps and slats control angle of attack (flap pulse) as well as
camber. The blades are thick and rigid -- more like rotating
wings than helicopter blades.
The engines freely rotate about their center of gravity. There are no
actuators between the engines and blades. Their
rigidly affixed vanes orient the engines into the dominant air flow, be
it due to rotation or translation.
It was originally envisioned that the blades would have pressure
distribution sensors and computers fast enough to determine the optimum
blade configuration, and actuate the slats and flaps to achieve the
lift requested by the flight path Perturbation Computer in addition to
that required by the Level Flight Computer. Subsequently, the
simpler and less demanding digital lift approach in which analytical
and empirical techniques are used to predefine blade configurations for
small lift increments was selected. The resulting incremental
lift table is used by each Blade Computer to configure its blade to
satisfy the demands of the Perturbation and Level Flight
Computers.
Transition is stimulated when the translation velocity exceeds the
rotation velocity of the retreating engine vane. Then the
retreating engine vane orients its engine into the vehicle direction,
countering rotation, reducing lift due to rotation, and reducing
translation due to rotation, while increasing translation with engine
thrust. During transition, the engines wobble back and forth
from the perspective of their axis, ideally always swinging through the
arc with the nozzle down to provide lift with each rotation.
The retreating blade increases camber and angle of attack, and the
advancing blade decreases camber and angle of attack to avoid roll.
The advancing blade will continue to generate lift from some
combination of translation and rotation, regardless of
rotation. If the advancing blade generates enough lift to
sustain the vehicle in level flight, and the thrust of one engine is
sufficient to accelerate the vehicle in level flight despite its drag,
the only problem is roll, because the retreating engine is retarding
rotation and contributing to translation the moment its vane
translation velocity exceeds its rotation velocity. The
retreating blade can compensate for roll with lift due to rotation with
high camber and angle of attack until its rotation speed is canceled by
its translation speed. Then the retreating engine thrust
could be deflected to provide the compensating lift necessary to avoid
roll, and enable transition without a loss of altitude. Catalytic
thrusters or RALS could be used in addition to or in lieu of
thrust deflection to counter roll.
Assuming the engine and vane moment of inertia is less than the blade
moment of inertia, and the vane aerodynamic moment is large enough, the
engine and vane will flip in the direction of vehicle travel
first. It may take a number of revolutions before the
retreating blade experiences enough translation flow to do
so. This behavior is a function of the size and shape the
vane (aerodynamic center relative to engine pivot axis).
The Blade Flyer must anticipate the last rotation, and use differential
thrust and/or vane split flap drag to stop rotation with the blade
chord aligned with the vehicle direction, and subsequently control yaw
during conventional flight with differential vane split flap drag
(unless the four-blade configuration is used).
Contact: Bill Holmes via email or 661-305-9465
| Home
| Features
| Business Plan Contents
| Solicitation
| Original | Presentation | Tests | Perch
| Segmented | Components | Extended |