From: "David"
Date: 2/6/2004 1:07 PM Central

Any good online resources concerning the design of ducted fans? Hoping to
one day acquire a text on ducted fan design. I've used search engines just
wanting to know if there is something uber-good that I've missed. Thanx.

I met a guy here in Florida that flies a ducted fan gyro. It looked like about
24" diameter. He was telling me prop efficiency was down to about 60% with
paddle blades and high rpm. He used a Hirth since he needed the rpm. Apparently
he had no luck at 2700 rpm.

You might look at competition hovercraft for a start.

Dan, U.S. Air Force, retired