1752

Item 1752

OTHER: Miscellaneous - Thoughtless Ideas - Cyclogyro - Triplane / Quadplane?
This idea is incomplete and maybe impossible.

See '4P vibration 'Primary Concern' (in red below).

Picture:

Initial crude pictures of crude model; just to convey the idea.

Overview:

A Personal Arial Vehicle (PAV) with Vertical Takeoff and Landing ability (VTOL).

Hopefully

, the genesis of a simple, low-cost, stable, and easy-to-fly aircraft.

Perceived Advantages:

The rotor blades can be asymmetrical for greater lift during cruise.

There is no need to react the torque of the side-by-side rotors during cruise because the rotors are not turning.

Drawing:

Hover:

Cruise:

Notes:

Center of Lift:

During hover the center of lift of the rotors will be in front of their center of rotation. This longitudinally offset lift will be balanced by the lift of the proprotor at the tail.

During cruise the center of lift of the rotors will be on their center of rotation. Therefore the proprotor at the tail only provides forward propulsion.

The rotational speed of the rotors and the tilt of the proprotor will transition between hover and cruise in unison.

For calculations related to the longitudinal location of lift of the rotors see 'Thrust of Rotor blades' below

Eventually, all electric, with one motor for rotors and one motor for proprotor.

Flight-Control:

Consider using one of the SynchroLite's tails either the Ruddervator V-tail or the Stabilator.

Tail feathers tilt with the proprotor.

Rotor Blades:

Asymmetrical blades, because the do not have to operate in an inverted position.
Large taper and minimal cutout, to reduce the moments that must be transmitted to the fuselage.

Miscellaneous Information:

Rotation of the rotor.

The blades should probably have a large chord and the rotational speed of the rotors be fairly slow.
There could be 3 or 4 blades on each of the two rotors.

Rotation of the blades about their pitch axis.

During hover the blade will be operating in reverse velocity when it is near 270º azimuth:
The rotation may have a fixed position stop a pitch angle of +5º.
The act of rotation should probably be subjected to a dampening.

Thrust of Rotor Blades, re Balanced Force w/ 4-blade Rotors.

Common values such as; blade flat plate area, density of air and coefficient of drag, have been remove from the equation F = 1/2 ρ C_D A v²

Azimuths of the 4 blades:	0º, 90º, 180º & 270º	20º, 110º, 200º & 295º		45º, 135º, 225º & 315º
Number of active blades (see underlined above):	1	2		2
Azimuth of blade(s) of interest:	180º	110º	200º	135º	225º
Vertical velocity of blade(s):	100 fps	34.2 fps	94.0 fps	70.7 fps	70.7 fps
Square of the vertical velocity of blade(s): (v²)	10,000	1,170	8,836	4,998	4,998
Horizontal component of arm length(s):	1 ft	0.34 ft	0.94 ft	0.707 ft	0.707 ft
Moment of blades(s):	10,000 lb-ft	398 lb-ft	8,306 lb-ft	3,534 lb-ft	3,534 lb-ft
Sum of moment(s) of blades(s):	10,000 lb-ft	8.704 lb-ft		7,067 lb-ft

Primary Concern: The lift will significantly vary. Also, it will be at a rate of 4P.

Assuming that the rear proprotor's thrust and moment arm length are constants during hover, then the thrust and the moment arm of the cyclo... should/must be constants also.

The following table is the above table with the velocity significantly reduced. The ratio of the sum of Moments does not change.

Azimuth of blades:	0º, 90º, 180º & 270º	20º, 110º, 200º & 295º		45º, 135º, 225º & 315º
Number of active blades:	1	2		2
Azimuth of blade(s) of interest:	180º	110º	200º	135º	225º
Vertical velocity of blade(s):	10 fps	3.42 fps	9.40 fps	7.07 fps	7.07 fps
Square of the vertical velocity of blade(s): (v²)	100	11.70	88.36	50	50
Horizontal component of arm length(s):	1 ft	0.34 ft	0.94 ft	0.707 ft	0.707 ft
Moment of blades(s):	100 lb-ft	3.98 lb-ft	83.06 lb-ft	35.34 lb-ft	35.34 lb-ft
Sum of moment(s) of blades(s):	100 lb-ft	87.04 lb-ft		70.67 lb-ft

What is the coefficient of drag for a flat plate? This will be of interest to see what the tail proprotor must push.

Note that an additional rotational drag on the rotor will be created by the rotation of the blades in the region of 270+º azimuth. This additional drag may impart a forward thrust on the craft.

The following is copied from OTHER: Aerodynamic - Drag - Parasitic [D_P]

Working in (English) units
F = 1/2 ρ C_D A v²

Where
F is the force [in pounds]
ρ (Greek letter "rho") is the density of air = 0.002377 slugs/foot³(The paragraph below says to use pounds per cubic foot, which is actually = 0.0765 pounds/foot³, but it appears that the slugs/foot³ value is the correct one.)
C_D is the coefficient of drag; which is 0.04 for a streamline strut (NACA 0025), 1.0 for a round wire, 2.0 for flat wire or 1.5 for a parachute. For values for helicopter component shapes see [Source ~ RWP1 p.280].
A is the area of the surface [in square feet]
v is the velocity through the air [feet per second]. (To convert from miles per hour to feet per second; multiply mph by 1.4667)

Outside Information:

The Development of cyclogyro

20090226314 ~ Cycloidal rotor with non-circular blade orbit ~ September 10, 2009

Performance of a Cycloidal Rotor Concept for Micro Air Vehicle Applications, Moble Benedict, Manikandan Ramasamy, Inderjit Chopra, and J. Gordon Leishman, J. Am. Helicopter Society 55 022002 (2010) Full Text: [ PDF (2544 kB) ] ~ On Scitation

Hover Performance of a Cycloidal Rotor for a Micro Air Vehicle, Jayant Sirohi, Eric Parsons, and Inderjit Chopra, pp. 263-279, ~ Have Journal

Other Concerns:

Will the air reattach to the blade quickly enough after the deep stalled flight in the vicinity of 180º azimuth during hover and vertical flight?

Will the stalled flight cause excessive turbulence?

The proprotor will be very close to the ground in hover mode.

The proprotor would provide greater stability if it had a higher elevation during hover.

Both of the above concerns can be overcome if the proprotor tilts the same as the rear proprotor on the AeroVantage 1x2.

Autorotation. May have to be fixed-wing type of landing only??

Does the reverse velocity flow present a problem? It will disappear when the rotor has an advance ratio of and greater.

Initially displayed: August 25, 2009 ~ Posted on Rotary Wing Forum; August 29, 2009; ~ Latest revision; February 15, 2010

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.