High-Drag Areas on the Supermarine Spitfire

Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules


I believe that screen was not adopted because it distorted the pilot's view, and so was deemed unsuitable for combat aircraft.

PR Spitfires did adopt a rounder profile screen, without armoured glass, for extra high altitude performance. They may have been related to the screen you mention.

Also, don't forget that the two cannon barrels cost ~8mph in speed.

Delete the cannon (presumably for 4 x 0.50"), add the super screen and improve panel fit and finish, and you would not be far shy of P-51 performance. But with less firepower than a regular Spitfire.
 
You would almost think that' someone looked at the Spitfire and Bf109 and thought how to improve on them.
 
I didn't think it was about changing the divergence angle so much as simply getting rid of the turbulent airflow going into the ducts. Regardless, I prefer the term "diverter" but that's a term used in jet-powered aircraft.
nobody was really using splitters in the mid to late 30s.
Click to expand...
The P-38 used them on the radiator scoops.
On the Spitfire there was limited room to work. . . . The radiator is already shoved as high into the wing as it will go. and you have limited space in between the radiator and landing gear to get a nice curve in the duct.
Click to expand...
Wow, I never realized they had such little room. A belly-radiator would have definitely fixed this, but you wouldn't want to belly in with it...

stona said:
Notice the date on this communique.
Click to expand...
August 10, 1942...
Then there was a constant barrage of advice and instruction issued by the RAF to Fighter Command and its squadrons about MAINTAINING the finish on service aircraft. Generally, even in the UK, this was not done very well.
Click to expand...
Out of curiosity -- how did the US & Germany compare?

Do you have a link to the page -- I don't think that qualifies...
I can quote from it though !

It raised top speed from 410 to 415mph (in level flight in a Spitfire IX reg "EN 498"), when dived at 550mph it put +12mph on top speed.
Click to expand...
Impressive
I also have another report on Spitfire aero, which stated that basically the fit of the panels was awful and resulted in (they reckoned) 7.5mph differences production models depending on how well it was fitted together at that particular factory.
Click to expand...
So workmanship sucked?
 
Zipper730 said:
Do you have a link to the page -- I don't think that qualifies...
Click to expand...

There isnt really a link as its an archive paper I photographed myself in London ... sorry.

Discovery | The National Archives

Search for

AVIA 6/10404

All that gets you is the index listing for it though....you CAN order copies but they cost an absolute fortune. So most people visit.
 
Last edited:
Washout to avoid a harsh stall doesn't do much for drag.
There was also the issue of landing gear that didn't quite fit into the thin wing and some of it had to hang below the wing surface.
 
Ivan1GFP said:
Washout to avoid a harsh stall doesn't do much for drag.
There was also the issue of landing gear that didn't quite fit into the thin wing and some of it had to hang below the wing surface.
Click to expand...

Funny that the prototype initially had fully enclosed main landing gear. The Mk III also had fully enclosed landing gear, IIRC.

The landing gear did not protrude from the wing, but some of the wheel well was open, which would cause some drag. Though the decision to remove the covers was made in testing the prototype.
 

My understanding was that the mid production Spitfires had large enough wheels that their gear doors were very slightly below the wing's lower surface. This was corrected with the change in the wing with the last marks.
 
I thought I saw something on here to this effect. It may be a bit off topic, but I've seen references to what is suspected to be RJ Mitchell's last major design he worked on before his death, which was the Supermarine 312. From what little I could glean from it, it was basically a Spitfire but much modified, namely with a ventral radiator and standard cannon armament. Outside of that, though, I've been quite frustrated to find other details about this design.



But it does show that it may be possible to fit such a radiator onto a modified Spitfire design, but, one, Mitchell died before the design was 100% complete or built, and two, as you hinted at, Joe Smith (Mitchell's associate/design assistant and successor) may've been inspired by that design and maybe even the P-51 later to try and modify the Spitfire, but he was turned down by the RAF and the Air Ministry. Which IMO is odd, given how much the Spitfire already evolved (though I did read that for the most part, the fuselage between the front firewall and tail was little modified from the Mk V on until the 22/24 line).
 
Last edited:
From my understanding of things, a ventrally mounted radiator caused compressibility issues mounted there, it has to be further back behind the area of max cross sectional area, as on a P-51, also on that arrangement the frontal area is increased, on a P51 the inlet is visible on a frontal view, but the "splitter" isnt..
 
I wonder how well the Spitfire would've done if it used radiators similar to the Spiteful? I'd bet that's probably a big part of why the Spiteful was nearly 40 mph faster than the Spitfire 14.
 
I am not sure the Spiteful radiators really did that much.

A lot wider than the Griffon Spitfires but shallower. More of the radiator could be hidden inside the wing rather than sticking out. Now notice where the intake flap hinge is and barely visible in the exit hinge.

Both flaps open at least part way. Granted this set up does not have the air making large excursions in the vertical and rejoining the exit flow. BUT you don't have the depth front to back to expand the airflow, get it through the radiator, and squeeze the heated air down to the higher pressure. May be it did work but you had nowhere near the depth front to back that the Mustang, CA-15, MB-5 and P-82 have

The only way to truly know is for somebody to have mounted instruments in the airflow coming out through the exit nozzle/flap and recorded the exit speed vs the intake speed.
That will tell you if you actually achieved positive thrust. Wither the thrust is worth the drag of the size of the scoop is another story.
 
The prototype (the second pic in #57 ) VG471 is the Supermarine Sea Fang F.31 while the RB515 in the first image above is the Spiteful, the first production aircraft.

Here is comparing of the Spiteful prototype NN664 and RB518 of the production series and the MV259, a Spitfire PR Mk. XIV. It looks like the angle of the windscreen was slightly different if compared to the ealier one. However it could be a trick because of the different windscreen frame for both types. IMHO the Spiteful and Sea Fang got the longer front glass.

NN664-RB518


NN664-MV259

the pic source: the net


the source: Supermarine Spiteful and Seafang Fighters
 
To be honest, I do wonder how much the Meredith effect is fact vs myth. Obviously, there's something to it, as with laminar flow wings. But I don't think that theory 100% paid off in terms of real world results. It's like comparing the P-51 with the Spitfire. When powered by similar engines, the P-51 was a good 30 mph or so faster on top end than the Spitfire, and it took the Griffon engined Mk 14 at least 300-400 more bhp to reach the same speeds.

Overall, I think that P-51 was just a cleaner airframe than the Spitfire. The fit and finish above all on the Mustang was seemingly miles ahead of a lot of Spitfires. You have to remember that it seemed that Spitfires didn't go fully to flush riveting for all external panels until sometime in 1943. The Mustang did this basically all along going back to the NA-73X prototype.

I do believe that the laminar flow wing and Meredith radiator done well helped, but they weren't the sole magic bullets. I'd bet that a lot of why the Spiteful was so fast was just lessons learned from designing the Spitfire and gains in manufacturing and aero made since the mid 1930s.

That's why sort of my "dream" fighter would have the best attributes of the Mustang and the Spitfire. IMO, we got pretty close with the XP-51F and G, and sort of approached that with the P-51H. Or maybe if the P-51B/C/D/K was able to keep the weight to NA-73X or P-51/Mustang I levels.
 
You must log in or register to reply here.

Users who are viewing this thread

Total: 1 (members: 0, guests: 1)

Similar threads

A
The Supermarine Spitfire
2
Replies
36
Views
3K
pbehn
P
Interesting Data on the Lorin Ramjet
Replies
1
Views
498
AMCKen
A
Where was the gun camera on the Bf 110?
Replies
6
Views
647
Snautzer01
Ballistics of British High Capacity (HC) bombs
Replies
17
Views
1K
33k in the air
Any Sources on Sea Level max speeds for the Ki-43’s?
Replies
4
Views
603
taly01
Menu
Log in
Register