while I'm not as lofty as aero eng I do mech stuff. Here is the end of the line in small ducted fans for model airplanes. A few years ago they were the ultimate rage. Some got over 200 mph !! They are vastly complex models. However thay have been of late surpassed by the turbine engine. These are very fast. Easly 200 mph straight and level. Honest ingen. You get a pretty nice car for the cost of these. And yes they do crash. Some even leave a smoking hole...literaly.
Check this site for ducted fans
MrChristian (Military Background)
Information relating to ducted fans might best be sought by an Airship Manufacturer. (or Blimp)
Many of these use piston engine pods with a ducted fan drive. Usually a small fan is used to enable turning to accommodate steering - low speed means a conventional rudder has little effect.
I believe Porsche engines were used by at least one .
Goodyeard might release some data - best of luck