I have had many ask why I have not designed and built a large EDF (electric ducted fan). The biggest reason is large EDF units are terribly expensive, plus they just are not big enough. A few years ago I had a bunch of 18-12 props left over from testing on my B-36 so I designed a make-shift (large) fan for a EDF unit which would be 12″ in diameter. While the test went well the fan was destroyed in testing. The picture attached is of the #2 test fan which never got tested (shown without hub), but the #1 fan gave me enough data to show me that my design and idea may work. The rendering is that of a fan unit which would go on a 200″ span A320.
Damon G. Atwood