I saw an ad for a gas leaf blower that claims it blows at 150mph. Would it work to just strap one of these to an R/C and make a ducted fan-ish plane? I realized that there would be alot of excess weight, but I was wondering if anyone had tried this. Does anyone know what 150mph equates to in lbs of thrust? If you had a gas engine spinning a 14X8 prop @ 8000RPM, that means that it would go ahead 8" per revolution assuming no slip. So, (8 inch/rev)(8000 rev/min)(60 min/hr)(1ft/12inch)(1mile/5280ft)= 60.61 MPH which is less than half of what the ad claims. My logic must be flawed here, or everyone would be strapping leaf blowers to their planes. Would the area of the prop disc vs the area of the blower tube make that much of a difference?

The leaf blowers have either a centrifugal or a squirrel cage impeller in them. To do what you want would require a straight Axle flow system.

Enjoy,

Jim

depends how much power you have

a normal ducted fan needs around 5 horsepower to put out 12 lb. thrust and 150 mph tail pipe velocity. most hand held blowers have around 1-1.5 HP at the most so no matter how much velocity they have the thrust is going to be all but useless.



dave