Spitfire with proper meredith effect

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Such an arrangement would probably help the CoG in later Spitfires, they had a lot of ballast weight already put in the tail. However it isnt simple as most things arent. The Mustang/P-51 always had the basic radiator layout that it had, but considerable work was needed to get it right when the Merlin was installed, and the Merlin needed additional radiators for its intercooler. The Griffon would also need more work to get it right, as it needed more cooling in proportion to the extra power it made.
 

I would imagine a Mustang style layout would make it easier to balance the aircraft after adopting a more powerful engine, as the bigger radiator behind the CG would partially make up for the higher engine weight ahead of the CG.
 
"Proper" Meredith would require:

The possible recovery is, however, considerably increased if we can add the exhaust heat as well. This may be achieved by enclosing suitably finned exhaust manifolds in the duct behind the radiator or behind the cylinders in the case of an air cooled engine.​

From R&M 1683 "NOTE ON THE COOLING OF AIRCRAFT ENGINES WITH SPECIAL REFERENCE TO ETHYLENE GLYCOL RADIATORS ENCLOSED IN DUCTS", 14th Aug 1935 by F. W. Meredith.
 

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To get thrust you need a converging diverging outlet nozzle, and it has to adjust its orifice according to conditions. Ever see that Mythbusters episode where they tried propelling a boat with pressure bottles? It barely moved. NO NOZZLES!

By the way the BF-109 tried to handle the problem of drag off the wing mounted radiators by putting fairings on the flaps. Those Germans!!!!

 
Clayton Magnet said:
How about a lightened P-51, fitted with a two stage Griffon?
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Well the P-51 was lightened later by adopting less stringent standards on loading used by the British, mainly sway loading on landing / take off as I remember from discussions on here. Also from things drgondog posted the Griffon wouldnt readily fit in a P-51. It would have been a helluva plane though, but not as an escort fighter in my opinion, the Griffon would use more fuel at all times, not just because it used more fuel, but being bigger and heavier it caused more to be used anyways.
 
There was(is?) a P-51 with a Griffon racing in Reno. That's of course a somewhat different proposition than a warplane, but still..

Anyway, just like the Spitfire could be adapted to take a Griffon, surely so could a Mustang. I guess there was no huge interest for it as the Allies were already comfortably winning the air war over Europe with the Merlin powered one, and further ahead jets were coming.

As for the fuel consumption, I believe the BSFC of the Griffon and the Merlin are pretty close. Of course with a heavier engine and radiator there would be more lift-induced drag which would reduce the fuel economy of the Griffon version. Would it be a big reduction, I don't know.
 
BSFC is not applicable in some cases of an escort mission. The laws of physics dictate that lifting a heavier weight to 30,000 ft takes more power, similarly pushing an engine that is 10 or 20% larger in XSA takes more power. But the killer is that when "on station" escorting a bomb group the plane maintains a cruise speed sufficient to be able to engage if attacked, circling or zig zagging above or around the formation but the forward speed is that of the bomb group. Also a Griffon being heavier may also need a stronger structure, undercarriage etc
 



There have been 3 Griffon Mustangs, each very different from the others.

This was the first, and was quite successful. It dominated the pylons from Reno to Miami for a while, and set the 3 Km absolute speed record -- 499 mph on a cold windy day...

It was heavy, though, and carried quite a bit of lead in the tail.
 

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Or, use a different means of compression and combustion then send all the gases and heat down a single pipe, let's call it a "jet". Interesting how much science and research pointed to the jet engine without anyone realising it. Turbos, suprcharfers, exhaust thrust and Meredith effect were ways to work around the problems set by Otto cycle engines.
 

I think they realized it alright. After all steam turbines were fairly widespread at that point. The limiting factors were improved understanding of compressor and turbine aerodynamics, and high temperature alloys.
 
z42 said:
I think they realized it alright. After all steam turbines were fairly widespread at that point. The limiting factors were improved understanding of compressor and turbine aerodynamics, and high temperature alloys.
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After the event, when a jet engine was run and proved to work everyone became suddenly wise. Before that many questioned whether the calculations were correct and it could have a surplus of jet thrust.
 
Theoretically they should equip all inline fighters with P-51-esque Meredith-worthy radiator installations.
Might have made the venerable Hawker Hurricane a contender for the mid-war years.
 
spicmart said:
Theoretically they should equip all inline fighters with P-51-esque Meredith-worthy radiator installations.
Might have made the venerable Hawker Hurricane a contender for the mid-war years.
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Not a chance, you need a complete re design of the whole aircraft. As I understand it from stuff posted here there was a 30MPH difference in speed between the Spitfire Mk IX and the P 51B with same RR two stage Merlin/Packard engine. Of that 30 MPH difference, in ball park numbers 10 was due to the cooling set up, 10 due to the "high speed low drag" wing and 10 due to the overall fit finish, and cleanness of design. The Spitfire plucked a lot of low hanging fruit in high speed design, the P-51 went up to a much higher level, reflecting the age difference and knowledge difference of the two types. The Hurricane was an even lower level, a stop gap to give the RAF planes to build a force with that ended up in production until late in the war due to thee failure of other Hawker products.
 
Let's not forget that when the Hurricane was designed, inside Hawker it was called the "monoplane Fury", a.k.a. what is the least-effort path to convert the Fury to a monoplane? And in the end, they achieved not only that, but they added a retractable landing gear, an enclosed cockpit, upgraded from the Kestrel to the Merlin, and installed a much more powerful armament with 8x.303's. That's quite a few major improvements all in a single generation!

I think it's unfair to criticize the Hurricane for not having aerodynamics on par with the Mustang, a plane which wasn't even on the drawing board by the time the Hurricane was already in widespread service. As for retrofitting a Mustang-style radiator to the Hurricane and other aero improvements, well, as mentioned that's more or less a redesign. And seems Hawker was pretty occupied by the Typhoon/Tempest at that time, from where would they have gotten the resources to dedicate to improving the Hurricane? Or IOW, improving the Hurricane would in practice have meant delaying the latter aircraft, maybe not a worthwhile tradeoff (well, given what a trainwreck the Sabre turned out to be, one could argue that designing aircraft powered by anything else would have been a good choice.. ).
 
Actually all that was carried over was the method of construction. The Hawker method of a truss of steel tubes with wooden formers to give the final shape.
Wing was different airfoil, fuselage was bigger, tail surfaces were larger, etc, etc. etc.
The Hurricane was a plane that could be built in a Hawker/Gloster factory with exiting tooling but different jigs and fixtures.
 
Yes, that's a better way of describing it. I meant a plane designed as the simplest possible evolution of the Fury, in using the same type of construction etc., not that it would be only slapping a new wing on the Fury. Sorry for any confusion.
 
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