WIX Archives
Less efficient...
Posted by bdk on Wed Mar 06, 2002 12:12:19 PM
In reply top Re: Spitfire PR.XIX PS890 - ? posted by Mick on Tue Mar 05, 2002 09:35:19 PM
Because you could use higher power settings for takeoff and climb! (and who wouldn't?!)
Actually, from a pure efficiency standpoint, a large diameter, slow turning, single bladed prop would be best. That is why Rare Bear has gone to a 3-bladed prop. Of course prop efficiency is meaningless if you have insufficient blade area to absorb the power. Diameter is limited of course by the gear length and deck angle.
I would think that a contrarotating prop would have lots of interference drag between the blades, but that would be partially offset by the reduced fin angle possible (on a new design since the Spit fin isn't adjustable) and drag due to rudder deflection required to maintain directional control.
: Actually, I've wondered for some time whether a contra-pro
: p on a MkXIX would make it less or more fuel efficient or
: would it be the same, anyone know ?