Turbocharged Typhoon/Tempest

[wuzak]

How would the perofromance of a Typhoon or Tempest be improved with the addition of a turbocharger.

Could a turbocharger be fitted under the Sabre, behind the chin radiator? It would need to be the GE C-series turbo.

I'm guessing that the Tempest would benefit more due to its better aerodynamics (ie thinner, laminar flow wing). Altitude performance shoudl be transformed for both.

 

[Shortround6]

It was estimated that a 1000hp engine needed ABOUT 10 cubic ft of space for a turbo, inter-cooler and ducting. There may be some economy of scale but a Sabre is going to need at closer to 20 cubic feet.
Turbos were also rather sensitive to the temperature of the incoming exhaust gases. A few extra feet of piping may pay big dividends in turbine life. The blade type turbines could fail in a rather spectacular fashion. Some P-38s had 'scatter' shields in line with the pilot and a few other aircraft also had 'scatter' shields between turbos and crew positions.

There is no doubt that a turbo could improve the performance at high altitudes (sea level power at 25,000ft) however it may come at the price of 15-30mph in speed and less climb rate at low altitude.

 

[tomo pauk]

The quick dirty set up might be the one like in Fw-190 Kangaroo prototype - much of the turbine and whole inter-cooler mounted under belly, but not too far aft because of CoG reasons. The beard radiator might or might not interfere with inter-cooler? The Tested, say, in 1942? Streamlined as a brick, no doubt
The refined version might include the leading-edge intercooler and a more 'buried' turbo. Tested in 1943, applied in Tempest? Should gave a P-47 good run for it's money.

 

[GregP]

Since they stretched and tweaked the Typhoon / Tempest design so many times and for several powerplants, I concur that there could be some sort of turbocharged version developed. I also concur that while it would improve high-altitude performance, possibly considerably, it well might have cost lower-altitude performance. though bypass gates are possible to help minimize that ... at the cost of additional weight and complexity.

So my main question would be, "Did GB need more high-altitude fighters at the time ... or were the Typhoons and Tempests going to be used as fighter-bombers and ground attack aircraft at low altitudes in any case?" If they needed more high-altitude stuff, then a developed verion might well be advisable. But if the Typhoon and Tempests were primarily going to be used at low to medium altitudes, the extra complexity would not seem worth it and the gains in high-altitude performance might hardly ever be used.

So, while possible, I question the need ... but also do not popsess the knowledge of what was needed in WWII and when by Great Britain to say for sure.

Since GB only made so many planes on WWII, I assume tghat the turbocharged Typhoons and Tempests would come at the cost of fewer of something else. Since the Spitfires were so good at high altitudes in the 2-stage units, would the devloped new aircraft be as good or better at high altitudes. My take would be no since the power to weight ratio, a good indicator of high-altitude performance, was markedly better for the Spitfire and the new aircraft could hardly make a better power to weight ratio than the non-turbocharged version since weight would be added to the existing airframes and the power from the turbo would probably be of the turbonormalizing varirty, not additional HP at sea level.

 

[wuzak]

"Did GB need more high-altitude fighters at the time ... or were the Typhoons and Tempests going to be used as fighter-bombers and ground attack aircraft at low altitudes in any case?"

The Typhoon was originally planned to take over from the Spitfire and Hurricane. The Tempest suffered for lack of a high altitude development of the Sabre (because they were too busy making it reliable).

 

[wuzak]

It was estimated that a 1000hp engine needed ABOUT 10 cubic ft of space for a turbo, inter-cooler and ducting. There may be some economy of scale but a Sabre is going to need at closer to 20 cubic feet.
Turbos were also rather sensitive to the temperature of the incoming exhaust gases. A few extra feet of piping may pay big dividends in turbine life. The blade type turbines could fail in a rather spectacular fashion. Some P-38s had 'scatter' shields in line with the pilot and a few other aircraft also had 'scatter' shields between turbos and crew positions.

There is no doubt that a turbo could improve the performance at high altitudes (sea level power at 25,000ft) however it may come at the price of 15-30mph in speed and less climb rate at low altitude.

The Typhoon and Tempest were plenty fast at low altitudes to start with. A few mph maybe not hurt so much.

 

[Aozora]

Trying to work out where to fit a turbocharger on the Typhoon...there's not a lot of room.

 

[tomo pauk]

The space between pilot's seat and empenage looks rather ... empty?

The Tempest that never was would be my THE Tempest: 2 stage Griffon, paired with LE radiators.

 

[yulzari]

Rolls Royce were firmly of the opinion that the exhaust thrust of a supercharged engine was worth the mechanical drive of the impeller and the whole package easier to fit in an airframe than the piping etc. for an exhaust driven impeller of the period.

 

[Aozora]

The space between pilot's seat and empenage looks rather ... empty?

There would need to be some extensive redesign to cater for all of the ducting, exhaust wastegates etc (a' la P-47) by which time the weight and cg would be out of whack, requiring further redesign and lengthening etc. Would it really have been worth it?

The Tempest that never was would be my THE Tempest: 2 stage Griffon, paired with LE radiators.

There was a Fury tested with a two stage Griffon, except it stuck with the chin...

http://1000aircraftphotos.com/Contributions/PippinBill/5597L-1.jpg

vs the more elegant Sabre VII version

http://1000aircraftphotos.com/Contributions/PippinBill/6292L-3.jpg

 

[tomo pauk]

There would need to be some extensive redesign to cater for all of the ducting, exhaust wastegates etc (a' la P-47) by which time the weight and cg would be out of whack, requiring further redesign and lengthening etc.

There ain't such thing as a free lunch.
If you take a look at the Fw-190 Kangaroo (the one I've mentioned already), you will notice that exhaust ducting is an external affair. The compressor -> intercooler ducting is both short and would not present a cahllenge re. drag and space needed. Then we have an intercooler -> carburetor ducting, that one being behind the chin radiator, ie. nothing too draggy.
OTOH, the 'external turbo' setup, as a complete sytem, is a draggy thing, I've covered the possible evolution of the turboed Typhoon/Tempest.

Would it really have been worth it?

Ask wuzak?
Jokes aside, Allies did not needed yet another short range interceptor.

There was a Fury tested with a two stage Griffon, except it stuck with the chin...

vs the more elegant Sabre VII version

Tempest with LE radiators look to me as if it was designed by Pininfarina, the chin radiator Griffon version is plain ugly. Hence my humble request

 

[Aozora]

There ain't such thing as a free lunch.
If you take a look at the Fw-190 Kangaroo (the one I've mentioned already), you will notice that exhaust ducting is an external affair. The compressor -> intercooler ducting is both short and would not present a cahllenge re. drag and space needed. Then we have an intercooler -> carburetor ducting, that one being behind the chin radiator, ie. nothing too draggy.
OTOH, the 'external turbo' setup, as a complete sytem, is a draggy thing, I've covered the possible evolution of the turboed Typhoon/Tempest.

I wonder what such a contraption would be called? Jugphoon? Tyjug? Ugh[/I]?

Tempest with LE radiators look to me as if it was designed by Pininfarina, the chin radiator Griffon version is plain ugly. Hence my humble request

ie: Griffon engine Fury

Sabre VII

 

[tomo pauk]

On the money there

 

[Rick65]

Why would the British pursue fitting a turbocharger system to the Sabre engine? Why did they need a Tempest that performed well at high altitude?
The British had a technological advantage in their supercharger technology as evidenced by the two stage 60 series Merlin and if a high altitude Tempest was the objective this technology (or a two stage Griffon) should have been transferred to the Sabre (after it was made reliable) earlier than was done.
I cannot think of a single successful British designed WW2 era plane that was fitted with a turbo, nor can I think of a single successful turbo equipped fighter that was not designed around the turbo system. Happy to be educated on both points.
The P-47 , the successful WW2 single engined fighter fitted with a turbo was hugely designed around the system using experience gained with the AP-4 and the P-43.
The R2800 also offered a reliable engine to bolt the turbo system to, something that could not be claimed of early Sabres.

 

[Aozora]

I cannot think of a single successful British designed WW2 era plane that was fitted with a turbo, nor can I think of a single successful turbo equipped fighter that was not designed around the turbo system. Happy to be educated on both points.
The P-47 , the successful WW2 single engined fighter fitted with a turbo was hugely designed around the system using experience gained with the AP-4 and the P-43.
The R2800 also offered a reliable engine to bolt the turbo system to, something that could not be claimed of early Sabres.

God point. AFAIK the only successful mass produced turbocharged aircraft were built by the US, starting with the B-17 then the P-38, B-24, P-47 and B-29, plus some variants of the F6F, F4U, P-61 and that's about it off the top of my head. Other countries experimented with turbochargers, but the main method of boosting power at altitude remained the supercharger.

Aviation History from 1944. Browse historical aircraft from 1944 - 0392.html

 

[Rick65]

The only successful turbo fighters that I can think of are the US P-38 and P-47 both designed around turbocharged systems.
The other turbo fitted single engine fighters seem to have been botch jobs where a turbo (often unreliable) and all the associated gear was rammed into an existing airframe that didn't have adequate space in the right places.
Even the US with the most expertise in the area seem to have failed in fitting turbos to fighters that were not designed for them, I can see a turbo Tempest being even worse due to the British lack of knowledge of turbo systems and the Sabre engine.

Were there successful turbo equipped F6F or F4U?

Another experimental prototype was the XF6F-2 (66244), an F6F-3 converted to use a Wright R-2600-15, fitted with a Birman manufactured mixed-flow turbocharger, which was later replaced by a Pratt Whitney R-2800-21, also fitted with a Birman turbocharger.[31] The turbochargers proved to be unreliable on both engines, while performance improvements were marginal.(Wiki)

Wasn't aware of a turbo Corsair, would it have been this test type (Wiki)
XF4U-3: Experimental aircraft built to hold different engines in order to test the Corsair's performance with a variety of power plants. This variant never entered service.

 

[wuzak]

Why would the British pursue fitting a turbocharger system to the Sabre engine?

Bristol certainly did persue turbocharging technology. Not sure on Napiers. Rolls-Royce did try a turbo, but preferred the exhaust thrust.

Why did they need a Tempest that performed well at high altitude?

Why wouldn't they like that?

As I said before, the Typhoon was originally intended to replace the Spitfire. So performance at altitude would be a must.

The British had a technological advantage in their supercharger technology as evidenced by the two stage 60 series Merlin and if a high altitude Tempest was the objective this technology (or a two stage Griffon) should have been transferred to the Sabre (after it was made reliable) earlier than was done.

More correctly, Rolls-Royce had a "technological advantage" with their superchargers - namely the two stage Merlin and Griffon.

The Griffon and Sabre may be of the same capacity, but the supercharger would not necessarily provide enough air for a Sabre. Certainly the Sabre was capable of far more power than the Griffon.

Also, apart from MAP ordering Bristol to help Napiers with sleeve valve production, is there any case of British aero engine firms sharing their technology?

I cannot think of a single successful British designed WW2 era plane that was fitted with a turbo, nor can I think of a single successful turbo equipped fighter that was not designed around the turbo system.

Both points are correct.

The P-47 , the successful WW2 single engined fighter fitted with a turbo was hugely designed around the system using experience gained with the AP-4 and the P-43.

Also correct.

The Typhoon and Tempest were about as massive as the P-47, so if any other single engine fighter could take a turbo it would be them.

The R2800 also offered a reliable engine to bolt the turbo system to, something that could not be claimed of early Sabres.

The turbo shouldn't compromise the reliability of the Sabre any further. But it would put in another system that could fail.

 

[Rick65]

Napier certainly pursued a Sabre that would give better performance at altitude (and more power) as early as 1941 but they were looking at improved supercharging, not turbocharging. The urgent need to make the production Sabre reliable was the big priority, not improving high altitude performance, especially given the use of the Typhoon for ground attack.
http://www.secretprojects.co.uk/forum/index.php?topic=11807.15
From post #20
Here is the text of an email from Roy Gasson, Chairman of Napier Power Heritage replying to an email of mine about the E118 and E122

I hope the following answers your questions, apart from ploughing through
Flight Aircraft Production magazines of the era I am not sure what to
suggest for research.
The "Sabre E118" was a "Twin Contra-prop, 2 stage 3 speed supercharger"
design of November 1941, that never held a Series No. during its wartime
development.
The final design had a similar spec. the "Sabre E122" engine of 1946, by
then with a bulk injection carburettor, but this was not even tested, and
was to have 3350 bhp max. @ 3750 rpm. It was taken over by Rolls-Royce in
1947 by command of the Engine Production Ministry, to become their much
larger capacity "Eagle 2" which I believe they did not pursue into
production .