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Jane-DoH
8th Feb 2012, 01:00
What kind of wing works better when flying subsonic and supersonic

1.) A straight, tapered wing similar in basic plan-view to the X-3 or F-104

2.) A rhomboid wing similar in plan-view to the F-23


R.C.

kenparry
8th Feb 2012, 14:35
works better???

It would help if you could explain more of what you mean. Are you talking about L/D ratio, max lift, min structural weight, internal stowage volume, or something else? All those, and more, are design and performance considerations.

Jane-DoH
9th Feb 2012, 02:10
Ken Parry

It would help if you could explain more of what you mean. Are you talking about L/D ratio, max lift, min structural weight, internal stowage volume, or something else? All those, and more, are design and performance considerations.

1.) Which wing produces better L/D ratios at Mach 0.6 to 0.9 at

Sea-level
25,000 feet
35,000 feet

A: A thin, straight, tapered-wing similar in plan-view to the X-3 or F-104?
B: A rhomboid-wing similar in plan-view to the F-23?

2.) Which wing produces better L/D ratios at Mach 0.90 to 1.2 at

Sea level
25,000 feet
35,000 feet
45,000 feet

A: A thin, straight, tapered-wing similar in plan-view to the X-3 or F-104?
B: A rhomboid-wing similar in plan-view to the F-23?

3.) Which wing produces better L/D ratios at Mach 1.8 to 2.2 at

35,000 feet
45,000 feet
55,000 feet
65,000 feet

A: A thin, straight, tapered-wing similar in plan-view to the X-3 or F-104?
B: A rhomboid-wing similar in plan-view to the F-23?

4.) Which wing produces better L/D ratios at Mach 3.0 at

60,000 feet
65,000 feet
75,000 feet
110,000 feet

A: A thin, straight, tapered-wing similar in plan-view to the X-3 or F-104?
B: A rhomboid-wing similar in plan-view to the F-23?

barit1
9th Feb 2012, 02:32
F-104 wing is not that much different in plan from the F-22, except for the tip chord as a % of root chord.

The vertical plane of max thickness is nearly straight (i.e. little sweepback) in both cases. Both present a need for more aggressive area rule in the fuselage.

And Mach would seem to influence the planform much more than altitude, don't you think? Altitude influences the need for lower wing loading, thus (for a given GW) the required wing area.

barit1
9th Feb 2012, 02:39
And the very low aspect ratio probably is chosen more for dynamic reasons rather than steady-state performance. Concentrating the mass closer to the c/l means lower roll inertia, thus faster roll response. :ok:

Jane-DoH
10th Feb 2012, 23:30
barit1

F-104 wing is not that much different in plan from the F-22, except for the tip chord as a % of root chord.

I was talking about the Northrop F-23 wing-design not the F-22, though I suppose both are rhomboid

The vertical plane of max thickness is nearly straight (i.e. little sweepback) in both cases. Both present a need for more aggressive area rule in the fuselage.

Yeah, but the high-taper of a rhomboid wing would mean the shockwave would be in front of it until a higher mach number was reached, no? Wouldn't that mean less trim-drag until the shockwave went past the leading-edge?

And Mach would seem to influence the planform much more than altitude, don't you think?

Sorry, Ken asked if I explained more of what I mean in terms of performance figures so I put in both Mach and altitude.

Altitude influences the need for lower wing loading, thus (for a given GW) the required wing area.

True, but a rhomboid wing like the F-23 is larger than the wing of the F-104

And the very low aspect ratio probably is chosen more for dynamic reasons rather than steady-state performance.

I never really thought of that -- I simply thought lower aspect ratio was more conducive to low-speed performance. Admittedly putting all the mass in the middle with small wings will make you roll faster so long as the ailerons are at the tip and the wing doesn't twist too much.

barit1
11th Feb 2012, 14:09
a rhomboid wing like the F-23 is larger than the wing of the F-104

Somewhat in direct proportion to their gross weights. Remember the F-104 was called "missile with a man in it" - terrific zoom climb because of the hotrod engine, but hardly an efficient cruise vehicle. Although, the F-104A when upgraded to the late-60s J79-19 would indeed "supercruise" - the first operational fighter to do so.

In either case, F-104 or F-23, efficiency (in terms of fuel burn) is hardly #1 priority, given their missions.

18-Wheeler
11th Feb 2012, 22:04
Although, the F-104A when upgraded to the late-60s J79-19 would indeed "supercruise" - the first operational fighter to do so.

The second in fact, the English Electric Lightning was the first.