Thread: Discussion 200mph with 70mm
View Single Post
Old Oct 31, 2012, 09:45 AM
murdnunoc is offline
Find More Posts by murdnunoc
Victim of C.D.O.
murdnunoc's Avatar
United States, TX, Lubbock
Joined Oct 2007
4,088 Posts
I do think you make some good points on efficient aiframe type for speed.
The fastest wing for the least power is one with high aspect ratio and little sweep.That's how the pylons and hotliners get their efficiency.
However, an F5D or hotliner airfoil like MH43 is not the best for pure straight line speed, though.
Speed ships use a symmetrical or very nearly symmetrical foil since you don't need a very high lift/airspeed ratio when going 200mph. Look at all the F3S airfoils like MH54 and you'll see they're very symmetrical.

That brings the design of the plane to something like Claus's Slingjet that Frank flew his cut CS fan on.

I'm not opposed to running a pod-mounted fan, as long as I know it's efficient.

A 70mm CS fan sure wouldn't take 60K RPM. But do we know that a well-cut and balanced 90mm hub and blades wouldn't take it?
Cutting down the blades would add more pitch to them, so that would help out the efflux speed. I think. Right?
murdnunoc is offline Find More Posts by murdnunoc
Reply With Quote