Forward-Swept Wings

Definately a cool concept.

I managed to dig up a sketch for the Convair XB-53 which was apparently based on Nazi designs captured post-WWII. The FSW double as rear horizontal stabilisers and I assume the FSW was chosen in this case to enable an unrestricted bomb bay.
Convair XB-53

Also here is a prototype for the X-1 with FSW discussed earlier:
Bell X-1 FSW

found this picture of the P1214 that you might like too, it shows the layout better than the painting I posted before;

WOW .... it really struck me when you posted those plans of the P.1214-3 just how much of a similar shape it actually is to the Su-47, sure the underneath is a little different but from directly above they are almost identical. Check these plans for the Su-47. With the backward swept x-wings being shortened into the rear horizontal stablisers. And obviously no canards which might have destabilsed the P.1214-3, its a real shame they never pursued this design!!

I forgot to add, although the X-29 was never meant to result in an operational fighter, that didn't stop me dreaming up the Northrop Grumman F-29K Tigerbat

[doublepost




[edit on 19/1/07 by SteveR]

Originally posted by planeman
The type did see combat in Nigeria where it was used by mercenaries and destroyed a number of Nigerian fast jets, but obviously lacks the appeal of the Su-47.

www.eichhorn.ws...

Please explain how this defeated a number of fast jets?

Really nice model Waynos.

Originally posted by waynos
I forgot to add, although the X-29 was never meant to result in an operational fighter, that didn't stop me dreaming up the Northrop Grumman F-29K Tigerbat

I can't help but feel that the canards would hit the pylons lol anyways its really neat to see a fellow modeler and a "F-29K"

Nah, there's plenty of clearance, I rotated them to make sure That was actually why I changed them from the X-29's lower mounting. the weapons and canard layout are based on a Rockwell impression from 1978 showing their 'Sabrebat' design splashing a MiG 21.

Wierd, seeing my model brought up again after so long

I can't help but feel like the back of the 29 looks like a viggen or gripen to me. Anyone else? maybe an f-16?

I'd say a Gripen, yes. Ans also an F-20. But thats probably because it uses the same engine, so its bound to.

reply to post by The_Time_is_now


Of course, had their been more time, there would have been a forward swept wing version of the He-162.

Originally posted by kilcoo316

Originally posted by Figher Master FIN
What is it then that make some of the designs so unstable... Is there something wrong with the pressure and weight...
As for bomb planes that use FSW... The center of weight changes when the bombs are dropped...

……
Aircraft like the F-16 (ok, i think the original model may have been pure unstable), but all after that have reduced static margin - they are stable - just, but they have good control responses. Same for Airbus's 777 etc, reduced static margin, but not really for manoverability, more to reduce trim drag.
The EF-2000, Rafale and Gipen are all unstable (i.e. have a negative static margin = the aerodynamic centre of pressure is ahead of the aircraft centre of gravity) - this means they will automatically tend to pitch up, which gives extreme manouverability, but would be impossible for a pilot to handle - thus flight computers are used.

Sorry, if I comprehansion is correct, then I think only Eurofighter is unstable jet but Rafale, because all video I watched in which Rafale's foreplan deflected down during subsonic flight because the CoL will moving backward while jet flight within supersonic. So if Rafale is an unstable jet, mo matter supersonic or subsonic Rafale flew, the foreplan won't deflect down.

My opnion is that CoG on Rafale was originally setted behind the CoL, this design if I call it rightly is you named stable cause canards deflect down.
Same phenomenon didn't show on Eurofighter wheare Gripen is same as Rafale.

reply to post by waynos


Would you kindly to post all of those FSW layout concieved by UK designer?

very funny, could this be advantage of FSW?

since the airflow on a swept wing can be decomposed in a chordwise and a spanwise flows, the spanwise flow of a swept forward wing is directed towards the fuselage that act up like a wing shutting down plate

may be I understand it wrongly because my native language is not English.

[edit on 31-8-2008 by emile]

Originally posted by emile
very funny, could this be advantage of FSW?

Its well understood that that is the basic advantage of FSW.

Let me guess.

maybe sth showed wrongly to me.

In that express, "act up" could be "act upon", but to be wrong still. that should be "act on", which means affect or operate or do an action.

But that "shutting down plate" reeealy made me fall in confusion. Does it mean air brake? or sth else, please explain.

reply to post by emile




Does that help?

Thanks for your help, but let's go more advanced.

Yes, the picture you posted show a good advantage that FSW given, but consider the boundary layer FSW guided also will congregate towards fuselage, which cause enlarge drag quickly and increasingly. Thus, totally cancel out the efficiency the aileron brought to.

Furthermore, BSW only has one shock wave while it flight from transonic in to supersonic, but FSW will get three shock wave. The shock wave also is a sort of drag that supersonic fighter really want to avert or delay.

Originally posted by emile
But consider the boundary layer FSW guided also will congregate towards fuselage, which cause enlarge drag quickly and increasingly.

The horseshoe vortex at the wing root will destroy the boundary layer for both RSW and FSW designs.


The wing tip vortex on a RSW also affects the bound vortex - it reduces the effective angle of attack as you move towards the wingtip - losing lift.

For a FSW, this is semi-reversed, and the effective angle of attack of the wing towards the root is increased. Leading to an increase of lift.


Sure, you can twist the RSW to compensate, but that only works over a narrow range of AoA.

Originally posted by emile
Furthermore, BSW only has one shock wave while it flight from transonic in to supersonic, but FSW will get three shock wave. The shock wave also is a sort of drag that supersonic fighter really want to avert or delay.

3?

What is a RSW?

If there is no Ramp, where does the horseshoe vortecis come from?

yes, three shock wave will caused by FSW a/c because tip of FSW will hit the air before its leading edge.

[edit on 1-9-2008 by emile]