Team 585 (
http://www.team585.org) has carried along a design option of using a fan for bonus propulsion (wheels are primary propulsion system). We chose to perform a parallel design and build of the fan system, and if we felt like it was viable, we would integrate it for competition.
So far, so good. We measure approx. 8lb static thrust out of our Xoar 28x10 connected directly to a CIM. Assuming we get 2-4 lbs out of the final installation, that is still a
significant thrust augmentation.
Safety is a critical concern for us. We are using a lightweight beechwood prop that is shrouded with 0.050 6061AL and has 1/2in, 19 gauge steel mesh (i.e., rabbit cage) screen in front and back of the fan. We also incorporate a master kill switch at the driver's station to disable power, should that become necessary.
See initial test at:
http://www.youtube.com/watch?v=XyZMlztkiyI