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...other than relaxed stability. Every since fly-by-wire and relaxed stability, no new variable-sweep wings have been incorporated into aircraft design. Sure, it adds weight and complexity, but, with the now widespread use of composites and emphasis on both long endurance and high penetration speeds, could variable sweep make a come-back, for example in a supersonic/supercruising but long-loitering UCAV? I'd be interested in your thoughts.

Btw, I'm aware of the switchblade, but that design seems to be more trouble than it's worth, especially for a larger scale design.

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Elite Joined: Aug 19, 2004 Posts: 1089

Besides weight and complexity, variable geometry wings are difficult (if not impossible) to make stealthy. In addition, you don't have many (if any) wing pylon stations available for a swing wing design. You get a much more well-rounded aircraft without swing wings than with.

Elite Joined: Dec 16, 2003 Posts: 798 Status: Offline

Salute!

Rap has it nailed.

Swing-wings, big planes.

RCS is a bitch when you look at the wing roots.

later,

Elite Joined: Jan 14, 2004 Posts: 2454 Status: Offline

The last new variable sweep fighter that was produced was the Tomcat. Every U.S. fighter produced since then has a smaller turning radius, is lighter, easier to maintain, and has a lower RCS...even the Eagle.

The B-1 has an RCS something like 1/4 the size of the BUFF, but is by no means stealthy. Later, the B-2, of course, went to a fixed-flying wing design.

Variable sweep is archaic technology.

Elite Joined: Aug 02, 2006 Posts: 942 Status: Offline

Another thing is that Mach 2.5 has fallen out of favor as a prime requirement. Fixed wings are more than capable of supporting performances up to Mach 1.8~2 without compromising low speed handling and cruise efficiency. The BIGGEST reason for swing wings is to support flight in the Mach 2~2.5 bracket.

The problem is that that is not something we care about too much. We'll rather focus on being able to cruise at Mach 1.7 than being able to make a short dash at 2.5.

Newbie Joined: Aug 10, 2008 Posts: 17 Status: Offline

I'm kind of wondering if VG wings could gain more effectiveness if they had an increased ability to modify the aerodynamic characteristics of a fighter plane?

What if it could be used for forward sweep in addition to unswept and rearward swept configurations? Various advantages (and disadvantages) have been shown for FSW, so adding them to a jet's repertoire of planforms could potentially enhance its combat effectiveness when the situation calls for it (such as high agility and high AoA performance).

Would I be correct in assuming that the Tomcat and other such VG aircraft utilized a mechanical method for moving the wings? Might a system that uses electromagnetic components to move the wings be more efficient and less likely to break down? You know, like how some levitating trains and roller coasters use magnets to move. Using electromagnets powered by the aircraft's engines might offer a safer system as there are no moving parts (other than the wings themselves, obviously).

Feel free to shoot my ideas down, though.

Newbie Joined: Aug 03, 2008 Posts: 11 Status: Offline

Kryptid wrote:

I'm kind of wondering if VG wings could gain more effectiveness if they had an increased ability to modify the aerodynamic characteristics of a fighter plane?

What if it could be used for forward sweep in addition to unswept and rearward swept configurations? Various advantages (and disadvantages) have been shown for FSW, so adding them to a jet's repertoire of planforms could potentially enhance its combat effectiveness when the situation calls for it (such as high agility and high AoA performance).

Would I be correct in assuming that the Tomcat and other such VG aircraft utilized a mechanical method for moving the wings? Might a system that uses electromagnetic components to move the wings be more efficient and less likely to break down? You know, like how some levitating trains and roller coasters use magnets to move. Using electromagnets powered by the aircraft's engines might offer a safer system as there are no moving parts (other than the wings themselves, obviously).

Feel free to shoot my ideas down, though.

I think the electromagnetic components would probably be very heavy, not to mention power intensive. I think a wing like that also has problems with changing the CG and center of lift pretty dramatically, which probably wouldn't be able to be dealt with without further additions of weight and degradation of performance.

I remember you from DA, by the way!

Newbie Joined: Aug 10, 2008 Posts: 17 Status: Offline

Quote:

I think the electromagnetic components would probably be very heavy, not to mention power intensive. I think a wing like that also has problems with changing the CG and center of lift pretty dramatically, which probably wouldn't be able to be dealt with without further additions of weight and degradation of performance.

I figured that the center of lift would be a problem. I had the idea of using a variable-dihedral V-tail to help keep the center of lift under control, but that would add to weight and complexity.

Quote:

I remember you from DA, by the way!

You have an account there?

Newbie Joined: Aug 03, 2008 Posts: 11 Status: Offline

Kryptid wrote:

Quote:

I think the electromagnetic components would probably be very heavy, not to mention power intensive. I think a wing like that also has problems with changing the CG and center of lift pretty dramatically, which probably wouldn't be able to be dealt with without further additions of weight and degradation of performance.

I figured that the center of lift would be a problem. I had the idea of using a variable-dihedral V-tail to help keep the center of lift under control, but that would add to weight and complexity.

Quote:

I remember you from DA, by the way!

You have an account there?

Sure do.
http://prinzeugn.deviantart.com/

Hmm, now that I think about it, it'd be pretty hard to get all the connections (electrical, etc.) to work correctly on that through the whole range of motion. And pylons. Although, really, that would be a trip to get that working... an aerodynamicist's wet dream.[/url]

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