1679

Item 1679

DESIGN: AeroVantage ~ PropRotor - Hub - Thrust Related Considerations

Notes:

Will the program; external for the calculations for a Torque-Pitch Coupling, or internal for an onboard computer control, require the input of GW etc. before flight.

A question is whether this automatic thrust-pitch coupling will provide a 'crisp' liftoff. Electric motors can deliver much higher power for a second or 2 and hopefully this will be enough to quickly increase the pitch and thereby increase the RPM slightly at the instant of liftoff.

This is related to the objective OTHER: Miscellaneous - Thoughtless Ideas - Torque/Pitch Collective Rotor Hub

The database that is under development is [Torque-Pitch Coupling]. The objective is to see if this is possible to do.

Variables: ►

Inclination: [α_S] Proprotor's longitudinal shaft angle vertical at zero degrees, positive aft.

Remote Velocity, Free stream velocity [V]

Induced Velocity: [v], ~ [v₀], [v₁], [v₂]

Rotational Inertia: [J_M]

Centrifugal Force: [CF]

Thrust: [T] = 2 * ρ * V² * A

Power [P] ≡ Torque [Q] * Speed [RPM]

Drag [D]

Induced [D_i]

Profile [D_o]

Parasitic [D_p]. This drag is only applicable during forward flight, plus the cosine of the angle of Inclination during transition.

Angle of Attack [α] = Pitch [θ] + Inflow [φ]

Delay: [Ð] [¦]

Drag [D] = Cd * rho * V²* A / 2

HP = Torque * RPM / 5252

Calculations:
ΔP^↑ ► ΔQ^↑

ΔQ^↑ ► Δα^↑

Δα^↑ ►Δθ^↑

ΔQ^↑ Ð► ΔRPM^↑

ΔRPM^↑ ►ΔΦ^↓

ΔRPM^↑ ►ΔCF^↑

ΔRPM^↑ ► ΔD^↑ + ΔT^↑

ΔT^↑ Ð►Δφ^↑

ΔRPM^↑ ► ΔQ^↑

α_S^↑► Δθ^↑

Δα^↑ ► Δθ^↑ + Δφ^↑

Couplings:

General:

A change in Power will first change the Torque, then the Torque will change the Rotor's Speed.

Torque-Pitch:

Speed-Pitch

Rotor's Speed [RRPM] is held constant. Pitch is changed to suit change in Power

Delay in the conversion of torque change to RPM change or Pitch Change

Required for time to convert ΔQ to Δθ

Polar moment of inertia of mass. [J_M] sometime denoted by [I]. In metric SI system the units are kilogram-meter². In foot-pound-second system the units are ft-lbs-sec²and slug-ft². (1 slug = 1 pound second² per foot). In inch-pound-second system the units are inch-lbs-sec².

Appears in dynamics equations involving rotational motion.

The resistance to change of a body in circular motion. Also known as Gyroscopic Inertia.

J_M bears the same relationship to angular acceleration as mass does to linear acceleration.

See also rotational inertia on this page.

Value for cylinder: J_{M =}¹/₂mr²~ r is the radius of the cylinder.

Value for hollow cylinder: J_{M =}¹/₂m(R²+ r²) ~ R is the outside radius of the cylinder. r is the inside radius.

Value for disk with mass (m) considered as being concentrated at the radius (r). J_{M =}m * r²

Initially displayed: October 2, 2005 ~ Last Revised: October 8, 2008

The above utility invention is openly and publicly disclosed on the Internet to negate an entity from patenting it, to the exclusion of all others whom may wish to use it. ~ Reference patent law 35 U.S.C. 102 A person shall be entitled to a patent unless - (a) the invention was known ... by others in this country, ..., before the invention thereof by the applicant for patent.