No Laughing Matter

[rookie]

Does anyone know the truth about Nitrous being used on Airplanes in WWI or WWII?

[automotivebreath]

Originally Posted by rookie

Does anyone know the truth about Nitrous being used on Airplanes in WWI or WWII?

Nitrous oxide

Originally Posted by Wiki

...used during World War II by Luftwaffe aircraft with the GM 1 system to boost
the power output of aircraft engines. Originally meant to provide the Luftwaffe
standard aircraft with superior high-altitude performance, technological
considerations limited its use to extremely high altitudes. Accordingly, it was
only used by specialized planes like high-altitude reconnaissance aircraft,
high-speed bombers and high-altitude

[DavidVizard-GFN]

I do not know of any use of N2O in WW1 but it was used in WWII by both the allies and the Axis powers. ME 109's had the GM1 system with auto fuel enrichment and it was supposedly good for about 300 hp. The FW 190's with their radial BMW engines had a similar sytem by all accounts but this needed the pilot to add the extra fuel. After WWII was over it seems that investigations by who ever it was supposedly found that better than 25% of the FW190 accredited with being shot down were infact downed due to an engine melt down because the pilot, in the heat of battle, had overlooked fuel enrichment! For at least the first year or so of it's use the Germans thought they were the only ones using it and figured it to be one of their secret weapons. The allies also thought the same!

The allies used nitrous on those occasions when it was obvious that there was no alternative. For instance the Germans started flying high altitude and perssurized recon flights over England. In response to this DeHaviland rebuilt a Mosquito to a special spec. I am not 100% sure of the exact details but this is how I remenmber it:
Added 6 feet into each wing. Stripped all the guns out except for one 20 mm cannon with aboit 20 rounds. Made a simple pressurized cockpit for one man crew (usually two). Upped the suppercharger gear ratios on the twin Merlins. (could make about 1500 hp a piece at 35,000 ft)Carried three 80 lb. N2O bottles to gas feed the Merlins at altitudes above about 45,000.
This Mosquito got to 55,000 ft - that's some 7000 above the enemy aircraft. It dived in and at near point blank range blew up the intruder.
No more came over!

[seattle smitty]

The Luftwaffe was forced to go to nitrous just to keep up, and this was a fuel issue. The Allies had 100/130octane av-gas by the beginning of the war, and later got the purple 115/145. The Germans made do with the equivalent of our 80/87 throughout the war. Some think this had a lot to do with the RAF winning the Battle of Britain, since the German planes had shorter range and could spend less time over the target than they would have had their engines been built for the high octane fuels. The Germans had to build bigger, heavier engines to do the same job, and carry ADI (water/alky injection systems) for high-boost situations, which added more weight, and finally the nitrous.

[Billzilla]

Just reading this thread, and it reminded me of a clever German WW2 high-altitude aeroplane, the Dornier Do 217p.
As you can see, it had a third engine buried in the fuselage and that drove a very large supercharger, which in turn fed the two wing-mounted engines.

I was going to use this idea in Australia, for the SummerNats dyno challenge - Since it takes a fair bit of power to drive a big blower or even a turbo, why not have another engine in the boot doing that for you? You could have a very large and cold intercooler and the main engine under the bonnet wouldn't have the large parasitic loss it would otherwise.
I figured I'd get away with it just the one time ....

[Devious]

My understanding was that 50 of the Mosquito NFXIII (nightfighter) models were converted to nitrous oxide use for aerial recon duty over mainland europe in the last year of the war. These were stripped of the RADAR equipment and pilot armor, and loaded with photographic equipment and nitrous bottles (with fuel enrichment).


NACA War Report E5F26 - June, 1945 - 38 pages
"Nitrous Oxide Supercharging of an Aircraft-Engine cylinder"

PDF format
http://naca.central.cranfield.ac.uk/...a-wr-e-199.pdf

Same report, but from NASA tech reports server:
http://ntrs.nasa.gov/archive/nasa/ca...1993093145.pdf

[seattle smitty]

Billzilla, your idea was actually tried by a top powerboat racing team in the mid-Sixties. "Tahoe Miss," owned by Nevada casino mogul Bill Harrah, had won the 1964 APBA National Points Championship for Unlimited Hydroplane using an Allison V-12 fighter plane engine instead of the then-favored Rolls-Royce Merlin. The Rolls advantage, in raceboats as in airplanes, came from its huge 2-stage, 2-speed centrifugal supercharger, which could make a lot more boost (max 130" MP!!)(The military 5-minute "war-emergency" maximum was 60") than the little single-stage blower used on most of the Allisons. Some of the raceboat crews, including Harrah's, were able to obtain later model Allisons, such as found on the P-63 Kingcobras, that had a second "auxilliary-stage" blower, or even the rare G-6 fuel-injected version from the P-82 Twin Mustang, and these could pretty well run with the Merlins. This was especially true for the early adopters of ADI and nitrous.

Having won the '64 championship, the Harrah's crew, led by Harry Volpi, went for the exotic. First they replaced the Allison superchargers with a huge turbocharger from a P-38. They mounted it out front of the engine, and it stuck up so high I don't know how the driver managed to see over it! I watched the boat go by, doing maybe 150mph, and could see the heated air coming off that giant turbo, which was giving off a very faint orange glow! The next experiment was to get rid of the exhaust turbo and power the supercharger section with its own engine, an aluminum Buick V-8, as I recall. The boat ran well with all of these experiments, but I don't know that it won any races; the Tahoe Miss was a big heavy sled, and the other crews had lighter hulls and had gotten better at injecting nitrous into the Rolls.

The final Harrah's effort was to ditch the Allison and install the big Rolls Griffon (found in the late Spitfires and the recently-retired Shackleton bomber/radar-patrol planes), but they still didn't win, and finally got out of the game. Later on, the Miss Budweiser crew under the direction of Dave Culley got a state of the art hull from Ron Jones (with substantial input from Culley) and all of the Griffons from Harrah. Culley made some expensive modifications to the engines, mostly to enhance reliability, and the Griffon-Bud won race after race with ease. The wonderful roaring V-12s are long gone from Unlimited racing which is now done with nasty-sounding helicopter gas-turbines, and this has ruined the sport for most spectators. The smartest move USAC ever made was to ban the vacuum-cleaner motors from the Indy 500.