Uni-UAV_Rotor

Overview:

The three blades per rotor or four blades per rotor, the two hubs and the static masts are rigidly mounted to each other. The pre-cone angle is 3 degrees, no flapping hinges, and no lead-lag hinges. The only movable components are those related to feathering. The direction of rotation is outside moving forward.

The NACA 00xx blade is currently being developed to try to achieve Active Blade Twist w/ Independent Root & Tip Control

Notes:

'Absolutely' Rigid Rotors

4-blades per rotors?

At maximum forward velocity, with 54"R, the tip speed is 456 fps. = 311 mph. Therefore for an mu = 0.5 the air speed will be 155 mph

Idea: Consider a non-variable slow speed for the rotors. During hover the angle of attack of the blades will have to be quite high, however this is an unmaned vehicle andt therefore the improved efficiency may be worth the greater risk of stall. I think that this is the principal behind Karems Optimum Speed Rotor. It will make things simpler and (check this out) it will provide for a lower angle of attack during high speed flight and the manuvering.

Reverse Velocity: At a forward velocity of 125 mph the diameter of the region of reverse velocity is 30". However the additional air speed past the retreating blades due to the propeller will result in this region being larger.

Blade:

No Taper: .75 R on the retreating blade is slightly outboard of the fuselage and on the retreating blade the outside 75% of span will be producing most of the lift therefor keep it wide. In addition, the outer 75% does not physically interact with the blades of the other rotor.

Consider using Vortech blades for prototyping and/or for mail mold for composite blades.

4.75" chord main rotor blades, 9' length: $850/set*** 54" for 2 blades

6.25" chord main rotor blades, 10' length: $1200/set 60" for 2 blades

Calculate the HP for the proposed 6" chord (9;1 reduction ratio) versus the 4.75" chord at a higher speed (xx;1 reduction ratio) and the 6.25" chord at the current speed (9;1 reduction ratio)

Looks like reduction must be 12:1 OR MORE. OR RUN THE ENGINE SLOWER DURING HOVER.

Idea: Place a carbon spar (tube) which has spanwise and diagonal thread inside the aluminum blade. It may be possible to give rigidity to the blade and/or tip pitch (active twist).

Idea: What will the actual length of the blade, less grip, be? It might be possible to make 3 blades from a 10 ft long airfoil i.e. 40".

Working Papers:

DESIGN:

MAKE:

BUY:

Secondary Grouping:

Disk

Design information related to the disks and blade interaction.

I/2-Scale UniCopter:	UniCopter: (Ref.)
Assembly:

Hub:	Hub (ARR):	Hub for Absolutely Rigid Rotor
	Blade - General (all blades)	Information common to all the following blades.
Blade - 8-H-12:	Blade - 8-H-12 - Aluminum:	From SynchroLite. For initial development.
Blade VR-7 -modified:	Blade - VR-7-modified:	Perhaps for future.

Same Page ~ Different Craft: ~ UniCopter ~ SynchroLite ~ Dragonfly

Last Revised: November 25, 2007