UniCopter-UAV - Fuselage

• Lifting Body:
• Using the fuselage as a lifting body will allow it to provide some of the lift during cruise.
• The lift that it provides (1/10th to 1/3rd of the weight ??) may reduce the lift required from the rotors and this should reduce the rotor induced vibrations.
• The lifting body will partially serve the same function of the wings on a compound helicopter, except the lifting body does not entail additional weight and it will not significantly interfere with the thrust of the rotors.
• This means that more power can go to the propeller and less to the rotors. This may also be closer to the optimum power distribution.
• Consider having the complete lower surface removable, since it is basically a large single curvature. Start carving out the foam. The lower surface can be a thin sheet and the the sheet can be built up into a double curvature, then a fiberglass shell prodiced.

• These could be contain; fuel, batteries, and mission equipment, in addition to the final gears and flight-controls.
• The bottom surface could be extended more outboard and have an dihedral angle so that it will assist in providing lateral stability and lift during cruise.

• Make the spars very strong and thereby have a relatively small x-section and parasitic drag during hover and forward flight.
• The spars should have an aerodynamic shape with a pitch angle of around ≥10º
• Vibration: Frequency of blade roots of one rotor and the blade tips of other rotor over a spar.

	Scale:	Full:	1/2:	2/5:	1/3:	1/4:	1/8:
	Rotor Speed; Hover | Cruise: [RRPM]	553 |	1,106 | ?	xxx | ?	1,659 | ?	2,212 | ?	4,424 | ?
	Frequency of passage of 8 blades:	73 /sec.	147 /sec.	? /sec.	221 /sec.	652 /sec.	590 /sec.

• The most objectionable frequency, for pilots, is 15 cycles per second. Ref. OTHER: Aerodynamics - Vibration - Rotor Induced - Overview. Obviously, the frequency on this Interleaving configuration is very high ~ Good.
• During Hover:
• The swirl from the retreating blades will reduce the angle of attack of the spar, when it is subjected to each blade's downwash.
• The pitch of the spar will reduce the spar's area in the downwash of the blades slightly.
• During Cruise:
• xx
• Perhaps the spar should be three smaller spars for aerodynamic reasons, although not so attractive.

• The boom will have a NACA0033 or NACA 0050 X-section. The so-called leading edge of the NACA airfoil will point straight up.

Introduction Page | SynchroLite Home Page | Electrotor Home Page | UniCopter Home Page | Nemesis Home Page | AeroVantage Home Page