Flying wing rotates for supersonic flight

MSimon · Post by **MSimon** » Tue Oct 16, 2012 1:42 pm

http://www.gizmag.com/rotating-bi-direc ... ign/23982/

DeltaV · Post by **DeltaV** » Tue Oct 16, 2012 3:28 pm

Barf. On par with Oblique Wing.

rjaypeters · Post by **rjaypeters** » Wed Oct 17, 2012 12:35 am

What's wrong with an oblique wing?

DeltaV · Post by **DeltaV** » Wed Oct 17, 2012 5:20 pm

rjaypeters wrote:What's wrong with an oblique wing?

http://en.wikipedia.org/wiki/Oblique_wing

That's a question best answered by having you pilot the vehicle while encountering wake turbulence behind, say, a 747.

I just prefer bilateral symmetry.

All this gives you over a conventional swing-wing is one less pivot.

Big deal. The flight control disadvantages are not worth it. The asymmetrical control problems in non-smooth air become worse with speed.

GIThruster · Post by **GIThruster** » Wed Oct 17, 2012 5:29 pm

DeltaV wrote:All this gives you over a conventional swing-wing is one less pivot. Big deal.

It is a big deal. The box that links swing wings to the rest of an aircraft is the heaviest part of the aircraft. The Oblique wing avoids this.

I would agree though that Oblique and star-shaped wings make little sense for other reasons. NIAC has made some very poor choices this last year.

DeltaV · Post by **DeltaV** » Wed Oct 17, 2012 5:44 pm

Problems of High Speed and Altitude

Page 6:

NASA Oblique Wing Test Vehicles

Stability and control issues
abound: The fact that birds and
insects are symmetric should give
us a clue (though they use huge
asymmetry for control)

– Strong aerodynamic and inertial
longitudinal-lateral-directional
coupling

– High side force at zero sideslip
angle

– Torsional divergence of the
leading wing

So you'll need bigger control surfaces, heftier actuators and stronger structure on the leading wing half. There goes your weight advantage.

The only desirable asymmetry is the transient kind, for control.

GIThruster · Post by **GIThruster** » Wed Oct 17, 2012 6:12 pm

DeltaV wrote:The only desirable asymmetry is the transient kind, for control.

Agreed. This bi-directional configuration loses the mass for a variable geometry wing, but gains the mass for twisting the engine location/direction, the cockpit, even the seats. There are so many needless complications here one fails to see how anyone could fund it. yeah, you can do a study with an RC aircraft for $10,000 but after that it should be obvious this is not a good idea.

I'm very disappointed with what NIAC II has come up with. The technologists at NASA seem to lack common sense.

rjaypeters · Post by **rjaypeters** » Fri Oct 19, 2012 1:58 am

Thanks for the enlightenment re: "what's wrong with an oblique wing?" In my experience, those who insist upon bilateral symmetry for its own sake tend to be limited in flexibility of thought.

Not liking oblique wings because of the raft of problems they bring is another situation...