Double Ring Wing Design Study:
"The Lantern"

This idea is completely different from the ideas I had up to now for a Free Flying Platform. It is very speculative, and I would appreciate any feedback on its feasability!

This construction is based on two ring wings, an upper one and a lower one, which have roughly the same diameter, but different airfoils. The airfoil of the upper one is designed so that the air has to flow radially from the outside to the inside. The airfoil of the lower one is designed so that the air has to flow radially from the inside out. In between the two rings, there is a separation layer in the form of another ring that separates the inwards from the outwards airflow. Located in the middle of the lower ring wing is a simple centrifugal fan that accelerates the air radially. The fan has many small but straight blades, and spins with high RPM. The air is accelerated towards the side (not downwards!), sucking air from above.

There are two sources of lift: The fan blows air radially towards the lower airfoil, which generates lift. Because the air is sucked in from above, and because the air inlets are bent radially towards the outside with an upside down conic middle piece, it is forced to flow over the upper ring wing, from the outside inwards, which also generates lift.

Note: Unlike vessels with axial fans, air is not sucked in from above, and it is not blown downwards. The air is sucked in from the side and also released to the side.

Click on the images for bigger pictures!

Initial drawing, made August 6th 2000.
Side view. The upper and lower ring wings are red, the seperating ring is purple, the inner structure is yellow, and the radial fan blue. Inside, slightly shining through, the direct drive motor (green).
Some flat electronic parts (receiver, servos) could be placed in the middle ring (purple). Heavier elements like batteries and video camera would be placed in the lower yellow section, underneath the motor. A sensor like a compass could be mounted in the the top conic piece. Of course additional control surfaces like flaps or vanes will be necessary to control the vessel.
View from below. Overall diameter of this prototype would be about 100mm, height about 75mm.
View from above.
Cross section.
Inside the vessel, half cut away.
Inside the vessel, one fourth cut out.
Detail radial/centrifugal fan with direct drive motor. The amount and shape of the blades of this design is just a first guess.
Detail radial/centrifugal fan with direct drive motor.
Detail radial/centrifugal fan blowing at lower ring wing.
Screenshot of the four wireframe views from the CAD software (Rhino).

Related technical stuff: Free Flying Micro Platform.

Send me some comments! Stefan Marti Last updated September 24, 2000.

Copyright © 2000 by Stefan Marti and MIT Media Lab. All rights reserved.