Model helicopter rotor driven by integrated blower jet

An experimental model helicopter rotor driven by an air jet generated by a blower fixed to the rotor hub and conducted through the hollow blades to the nozzles at blade tips.

Since the blower is directly attached to rhe motor, no power transmission mechanisms or gears are needed. There is no net torque to the axle or its bearings other than due to the bearing friction, and basically no tail- tandem- or coaxial rotor is needed for a helicopter assembly. As a result, the configuration can be kept relatively simple.

On the other side, the performance is relatively poor due to the pneumatic losses, mainly pipe flow losses inside the blades. Marked improvements relative to the current design are theoretically possible by slowing down the pipe flow speed inside the blades by increasing operating pressure by increasing impeller diameter while adjusting the nozzle correspondingly. With adequate nozzles, rotor speed of about 600rpm was achieved.

Currently, the rotor has no cyclic nor collective control.

3d-model was created with SpaceClaim direct modeller, part geometries were converted into stereolithography (.STL) files and sent to Shapeways for printing.

Some photographs: https://picasaweb.google.com/10545864...