More long-range Spitfires and daylight Bomber Command raids, with added nationalistic abuse (was: #1 Jet of World War II)

"Gord Beaman" ) wrote:
Alan Minyard wrote:

The Davis wing was a high aspect ratio wing with a low angle of
attack.

Is there something that I'm missing here?...

Probably, but then, that's nothing out of the ordinary for you.

how can a wing's design decide that?...I'd think that only the
elevators could control the AOA?.

He obviously meant low angle-of-incidence (e.g: the acute
angle which the wing chord makes with the longitudinal axis
of the A/C). Angle-of-incidence can vary depending on the
wing design.

-Mike Marron

Alan Minyard wrote:

On Tue, 9 Sep 2003 15:13:14 +0100, Dave Eadsforth
wrote:

In article , John Halliwell
writes
In article , Geoffrey Sinclair
writes
Apparently the outboard sections of the wing were watertight. Interestingly
the Stirling's wing area was 1,460 square feet, Lancaster 1,297, later
Halifaxes 1,275, B-17 1,420, B-24 1,048 and B-29 1,736.

I'm not disputing the figures above, but I thought the B-24 had a larger
wing area than most contemporary bombers allowing it to fly higher?

Was it not the thick section Davis wing that gave it the improved lift?

Cheers,

Dave

The Davis wing was a high aspect ratio wing with a low angle of
attack.

I'll step with some trepidation into Pete's territory here as he explains this
stuff far better than I do, but we've been keeping him busy doing calcs. The high
aspect ratio wing provides good L/D ratios, increasing range performance as well as
lift at low angles of attack. Here's how the a/c's aspect ratios stack up, from
low to high:

Stirling 6.72:1;. B-17, 7.58:1; Halifax (early) 7.81:1; Lancaster 8.02:1; Halifax
(late) 8.51:1; B-24, 11.55:1; B-29, 11.48:1.

As you can see, the B-24, designed a couple of years later than the British heavies
and five years or so after the B-17, has a much higher aspect ratio wing, and the
B-29 follows this practice. The wing area of the B-24 was considerably lower than
the others, for low drag. Good altitude performance requires some combination of
low wing-loading (high wing area for weight), engine thrust, and aspect ratio.

While the B-24 had good engine power at altitude and a high aspect ratio, it also
had high wing-loading compared to its contemporaries (not the B-29). It had better
altitude performance than the British a/c because of its engine supercharging, not
its wings. The B-17, with similar supercharging as the B-24 had a higher combat
and service ceiling, because although it had a moderate aspect ratio wing it also
had far lower wing-loading, and was able to fly slower. The B-24 cruised between
10-20 mph IAS faster than the B-17, but then it had to to be comfortable. The
crews hated having to fly in company with B-17s.

It's also easier to make lower aspect ratio wings of the same area stronger for the
same weight, because the stresses can be spread over a longer (and thicker) root,
which is one reason why a/c like the Stirling and B-17 have reputations for being
able to take lots of wing damage and survive, and why a/c like the B-24 had
opposite reps. However, the lower aspect ratio wing requires more area to get the
same lift at the same AoA, increasing drag.

Guy

"Gord Beaman" ) wrote:

how can a wing's design decide that?...I'd think that only the
elevators could control the AOA?.

Also see: F-8 Crusader

-Mike Marron

Mike Marron wrote:

"Gord Beaman" ) wrote:
Alan Minyard wrote:

The Davis wing was a high aspect ratio wing with a low angle of
attack.

Is there something that I'm missing here?...

Probably, but then, that's nothing out of the ordinary for you.

how can a wing's design decide that?...I'd think that only the
elevators could control the AOA?.

He obviously meant low angle-of-incidence (e.g: the acute
angle which the wing chord makes with the longitudinal axis
of the A/C). Angle-of-incidence can vary depending on the
wing design.

-Mike Marron

Really?...seems to me that the angle of incidence would be
decided by the way that the wing was mounted to the
fuselage...how could the DESIGN of the WING itself control the
angle of incidence?.

Some advice, Lay off the personal insults, they aren't helping
your image much.
--

-Gord.

Mike Marron wrote:

"Gord Beaman" ) wrote:

how can a wing's design decide that?...I'd think that only the
elevators could control the AOA?.

Also see: F-8 Crusader

-Mike Marron


Why?

--

-Gord.

Peter Stickney wrote:

In article ,
Guy Alcala writes:
The Revolution Will Not Be Televised wrote:

On Sat, 06 Sep 2003 19:07:13 GMT, Guy Alcala
wrote:

Not yet, but I've got a bunch of B-25/B-26 books on order from various libraries,
so hopefully they will have something useful. I've also been reading Alfred
Price's "Spitfi A Complete Fighting History," which has some interesting info
on Mk. V fuel burn, range, Spit drag, etc.

The most useful I found were the Merlin 45/46 consumption figures with
relevant TAS figures with associated rpm and boost.

That was one I was thinking of, but if you've seen it that will save me some typing.
I think Pete will find the drag numbers more interesting, but maybe he'd want to see
the Mk. V fuel burn numbers as well. If he does and you've got a scanner (I don't),
could you send them to him?

I'd love to see it, if I could. If you can't scan it, or cost is an
issue, or it's just too danged big (sheetfeed scanners are a Good
Thing), than photocopy it, and mail it, if you wish. I'd be happy to
scan it for you.

I haven't seen a reply from Gavin to this, so I'll just type the info in. This is from an
official memo sent around to the Fighter stations in August 1942, titled "How to Make Full
use of the Performance of the Spitfire V, VI, and IX." The fuel consumption data is from
Appendix A, "Spitfire VB and VC (Merlin 45 and 46): Approximate Petrol Consumption Figures
at Various Boost and Rev Settings." I'm going to list the data in the format ASI / TAS /
Height / Boost / Revs / Consumption in gal./hr. An asterisk following the latter says to
"Fly at these settings" (for max. range at the specified speed/height):

250 / 255 / 2000 / +4 1/2 / 2000 / 42

230 / 234 / 2000 / +2 3/4 / 1800 / 35*

- / - / 2000 / + 1/2 / 2650 / 40

200 / 203 / 2000 / - 1/2 / 1800 / 31*

- / - / 2000 / -2 1/2 / 2650 / 35

295 / 331 / 10000 / +9 / 3000 / 88

- / - / 10000 / +6 / 2650 / 70

250 / 281 / 10000 / +3 3/4 / 2000 / 42*

- / - / 10000 / +2 / 2650 / 47

200 / 225 / 10000 / -1 1/2 / 1800 / 29*

- / - / 10000 / -3 / 2650 / 35

283 / 368 / 20000 / +9 / 3000 / 88

268 / 350 / 20000 / +6 / 2650 / 70

258 / 300 / 20000 / +3 3/4 / 2650 / 65

240 / 310 / 20000 / +3 3/4 / 2400 / 50

230 / 300 / 20000 / +1 1/2 / 2400 / 46*

- / - / 20000 / +1 / 2650 / 48

200 / 263 / 20000 / -1 3/4 / 2200 / 36*

- / - / 20000 / -2 1/2 / 2650 / 40

216 / 335 / 30000 / +0 / 3000 / 47

180 / 283 / 30000 / -3 1/4 / 2850 / 41*

- / - / 30000 / -3 1/4 / 3000 / 43

Note that the 300 TAS entry for an ASI of 258 mph @ 20,000 feet is clearly a typo, either in
Price or the original. It probably should read 330 or more likely 340 TAS. The report also
states that Mk. V fuel consumption at +16 / 3000 is 150 gph. One of the paragraphs in the
report states "Spitfires are now modified to give +16 emrgency boost. It must be impressed
on pilots that this gives a great increase of speed under 21,500 feet and 18, 250 feet for
Merlin 46 and 45 engines respectively, and that if used for combat only there is no risk of
engine failure."

Here's the drag data promised, for the Mk. I. The drag is measured in pounds at a notional
speed of 100 ft./sec:

Profile Drag:

Wings, 20.3

Fuselage, 7.3

Tailplane, Fin and Rudder, 4.6

Effect of Camouflage Paint, 1.5

Total Profile Drag, 33.7


Induced Drag:

Lift, 2.4

Washout, 0.6

Total Induced Drag, 3.0


Cooling Drag:

Glycol Radiator, 6.0

Oil Radiator, 1.0

Air Intake, 1.0

Total Cooling Drag, 8.0


Miscellaneous:

Controls, 1.2

Windscreen, 1.2

Tail Wheel, 2.0

Wing/Body Interference, 1.5

Aerial Post, 0.2

Gun Holes, 0.5

Rivets and Joints, 0.5

Total Miscellaneous, 7.1


Not Accounted For, 8.4

Total Drag of Aeroplane, 60.2

There's also a fairly detailed weight breakdown for a Mk. I, but enough typing for now.

Guy

" wrote:

Mike Marron wrote:

"Gord Beaman" ) wrote:

how can a wing's design decide that?...I'd think that only the
elevators could control the AOA?.

Also see: F-8 Crusader

-Mike Marron


Why?

An example of an a/c that was able to vary its wing's angle of
incidence in flight. This was presumably intended to be read as
followup to his other message, where he postulates that Al Minyard
was referring to AoI rather than AoA, but that assumes you're
familiar with the F-8. I have a slightly different reading of Al's
intent, but we can let Al tell us what he meant.

Guy

In article , Guy Alcala
writes
Alan Minyard wrote:

On Tue, 9 Sep 2003 15:13:14 +0100, Dave Eadsforth
wrote:

In article , John Halliwell
writes
In article , Geoffrey Sinclair
writes
Apparently the outboard sections of the wing were watertight.
Interestingly
the Stirling's wing area was 1,460 square feet, Lancaster 1,297, later
Halifaxes 1,275, B-17 1,420, B-24 1,048 and B-29 1,736.

I'm not disputing the figures above, but I thought the B-24 had a larger
wing area than most contemporary bombers allowing it to fly higher?

Was it not the thick section Davis wing that gave it the improved lift?

Cheers,

Dave

The Davis wing was a high aspect ratio wing with a low angle of
attack.

I'll step with some trepidation into Pete's territory here as he explains this
stuff far better than I do, but we've been keeping him busy doing calcs. The
high
aspect ratio wing provides good L/D ratios, increasing range performance as
well
as
lift at low angles of attack. Here's how the a/c's aspect ratios stack up,
from
low to high:

Stirling 6.72:1;. B-17, 7.58:1; Halifax (early) 7.81:1; Lancaster 8.02:1;
Halifax
(late) 8.51:1; B-24, 11.55:1; B-29, 11.48:1.

As you can see, the B-24, designed a couple of years later than the British
heavies
and five years or so after the B-17, has a much higher aspect ratio wing, and
the
B-29 follows this practice. The wing area of the B-24 was considerably lower
than
the others, for low drag. Good altitude performance requires some combination
of
low wing-loading (high wing area for weight), engine thrust, and aspect ratio.

While the B-24 had good engine power at altitude and a high aspect ratio, it
also
had high wing-loading compared to its contemporaries (not the B-29). It had
better
altitude performance than the British a/c because of its engine supercharging,
not
its wings. The B-17, with similar supercharging as the B-24 had a higher
combat
and service ceiling, because although it had a moderate aspect ratio wing it
also
had far lower wing-loading, and was able to fly slower. The B-24 cruised
between
10-20 mph IAS faster than the B-17, but then it had to to be comfortable. The
crews hated having to fly in company with B-17s.

It's also easier to make lower aspect ratio wings of the same area stronger for
the
same weight, because the stresses can be spread over a longer (and thicker)
root,
which is one reason why a/c like the Stirling and B-17 have reputations for
being
able to take lots of wing damage and survive, and why a/c like the B-24 had
opposite reps. However, the lower aspect ratio wing requires more area to get
the
same lift at the same AoA, increasing drag.

Guy


Agree with all of the above analysis - and thanks for the useful summary
of aspect ratios; both the B-24 and the B-29 must have glided well...

To enlarge on my 'thick wing section' description, and working from
memory of a book read long ago (which can be fatal), I recall that Davis
conceived of a wing section that was based on a mathematically deformed
circle, which he believed would give a more laminar flow. The thicker,
'teardrop-shaped' aerofoil section that resulted was also very useful
structurally, given that he wanted to combine it with a high aspect
ratio wing.

Of course, any wing section inboard of the engines was going to have its
airflow messed up considerably by a few minor essentials; like engine
nacelles and de-icing boots etc etc, but the wing outboard of the
engines may have performed as Davis believed it should during cruise.

True that the high aspect ratio conferred most of the advantages of L/D
ratio, but perhaps Davis's ideas on the wing section itself should not
be forgotten.

Cheers,

Dave

--
Dave Eadsforth

Mike Marron wrote:
"Gord Beaman" ) wrote:

Is there something that I'm missing here?...

Probably, but then, that's nothing out of the ordinary for you.

how can a wing's design decide that?...I'd think that only the
elevators could control the AOA?.

He obviously meant low angle-of-incidence (e.g: the acute
angle which the wing chord makes with the longitudinal axis
of the A/C). Angle-of-incidence can vary depending on the
wing design.

Really?...seems to me that the angle of incidence would be
decided by the way that the wing was mounted to the
fuselage...how could the DESIGN of the WING itself control the
angle of incidence?.

When Al said that the "Davis wing was a high aspect ratio wing
with a low angle of attack," rather than be contrary, nitpick, pounce
at every opportunity, misconstrue and put words in people's mouth
so as to gratuitously insult and argue for the sheer sake of arguing
like you so enjoy doing, I simply gave him the benefit of the doubt
and assumed he meant angle of INCIDENCE rather than angle of
attack.

Some advice, Lay off the personal insults, they aren't helping
your image much.

I'll take this unsolicited, worthless and hypocritical advice from
whence it came: the Sultan of Insults: Sourpuss Don Rickles
(aka: Gord Beaman).

-Mike Marron

On Wed, 10 Sep 2003 02:23:14 GMT, Guy Alcala
wrote:

" wrote:

Mike Marron wrote:

"Gord Beaman" ) wrote:

how can a wing's design decide that?...I'd think that only the
elevators could control the AOA?.

Also see: F-8 Crusader

-Mike Marron


Why?

An example of an a/c that was able to vary its wing's angle of
incidence in flight. This was presumably intended to be read as
followup to his other message, where he postulates that Al Minyard
was referring to AoI rather than AoA, but that assumes you're
familiar with the F-8. I have a slightly different reading of Al's
intent, but we can let Al tell us what he meant.

Guy

Yep, I meant AoI, but my source called it AoA, so I slavishly copied
it that way. I agree that the F-8 was somewhat unique in its ability
to vary the AoI. Of course, with the fuselage horizontal pitch at 0,
AoI equals AoA :-)

Al Minyard