General Electric J31

After a visit to England mid-1941, General Henry H. Arnold was so impressed by flight demonstrations of the Gloster E.28/39 jet aircraft he had witnessed that he arranged for the Power Jets W.1X turbojet engine to be shipped by air to the U.S., along with drawings for the more powerful W.2B/23 engine, so that the US could develop its own jet engine.

General Electric's extensive experience in turbocharger production made that firm the natural choice for producing such an engine. The initial prototype, the General Electric I-A, was essentially based on the W.2B/23. It first ran on 18 April 1942 and developed a static thrust of 1250lbf.

The I-A air intake consisted of two peripheral slots which led to a double-sided, centrifugal compressor. A series of vanes guided the air into the impeller eyes. After radial compression, the air was diffused and turned 90 degrees rearwards, before entering a set of ten reverse-flow combustion chambers (i.e. cans). A relatively short shaft connected the compression system to the single stage axial turbine. After expansion through the turbine, the combustion products exhausted the engine through the simple conical propelling nozzle, via the jet-pipe. For the turbine section, GE used a proprietary metal developed for their turbochargers, Hastelloy B.[http://www.machinedesign.com/technologies/100-years-aircraft-engines Machine Design] (retrieved 30 May 2017)

Using their turbocharger expertise, General Electric were able, in a short space of time, to develop a {{convert|1400|lbf|kN|lk=on|abbr=on}}-thrust version, known as the I-14. Later they increased the thrust to {{convert|1600|lbf|kN|lk=on|abbr=on}}. This version was referred to internally as the I-16{{Cite book | url=https://books.google.com/books?id=GqhnBwAAQBAJ&q=General+Electric+I-A+engine+performance&pg=PA26 |title = Experimental and Prototype U.S. Air Force Jet Fighters|isbn = 9781580071116|last1 = Jenkins|first1 = Dennis R.|last2 = Pyeatt|first2 = Don|date = 2008-04-30| publisher=Specialty Press }} However, the United States Army Air Forces later decided to standardize all their jet engine naming, at which point the I-16 became the J31.

Production of the J31 started for the P-59 Airacomet in 1943, and by the time the lines shut down in 1945, a total of 241 had been built. GE also used the basic design to produce the much larger I-40 with 4,000 lbf, but this design was passed on to Allison as the J33. Another derivative of the J31, the General Electric I-20, given the military designation J39, was ordered but later cancelled.

Meanwhile, the British version of the W.2B/23 turbojet entered production as the 1,600lbf thrust Rolls-Royce Welland 1 in October, 1943. The Gloster Meteor I fighter, which entered RAF service in July, 1944, was powered by the Welland I.

• Bell P-59 Airacomet
• Ryan FR Fireball
• Ryan XF2R Dark Shark

File:GE J31 Aircraft Engine.jpg

• There is a J31 on display at the New England Air Museum, Bradley International Airport, Windsor Locks, Connecticut{{Cite web|url=http://neam.org/index.php?option=com_content&view=article&id=1049|title = New England Air Museum}}
• There is a J31 on display at the Hickory Aviation Museum, Hickory Regional Airport, Hickory, North Carolina{{Cite web|url=http://www.hickoryaviationmuseum.org/|title = Hickory Aviation Museum}}
• There is a J31 cutaway on display at the Military Aviation Museum, Virginia Beach, Virginia {{Cite web|url=http://www.militaryaviationmuseum.org/|title = Military Aviation Museum}}
• There is an I16 (J31) on display at the Aerospace Museum of California, Sacramento, California{{Cite web|url=https://aerospaceca.org/|title = Aerospace Museum of California}}
• There is an I16 (J31) on display onboard the USS Yorktown (CV-10) at Patriots Point, Charleston, South Carolina{{Cite web|url=https://www.patriotspoint.org/|title = Patriots Point Naval and Maritime Museum}}

{{jetspecs

|

|ref={{cite book|last=Wilkinson|first=Paul H.|title=Aircraft Engines of the world 1945|year=1945|publisher=Paul H. Wilkinson|location=New York|pages=270–271}}

|type=centrifugal compressor turbojet

|length={{convert|72|in|cm|abbr=on|0}}

|diameter={{convert|41.5|in|cm|abbr=on|0}}

|weight={{convert|850|lb|kg|abbr=on|0}}

|compressor=single-stage double-sided centrifugal

|combustion=10 reverse-flow can

|turbine=single-stage axial

|fueltype=kerosene (AN-F32) or 100/130 gasoline

|oilsystem=pressure spray, wet sump with scavenge cooling and filtration

|power=

|thrust={{convert|1,650|lbf|kN|abbr=on}}

|compression=3.8:1

|aircon={{convert|33|lb/s|kg/s|abbr=on|1}} at 16,000 rpm

|turbinetemp= {{convert|1,220|°F|°C|abbr=on|0}}

|fuelcon=

|specfuelcon={{convert|1.2|tsfc|si tsfc}}

|power/weight=

|thrust/weight= 1.94:1

}}

{{Aircontent

|related=

• General Electric I-A
• General Electric I-40/J33
• Power Jets W.2
• Rolls-Royce Welland

|similar engines=

• de Havilland Goblin

|lists=

• List of aircraft engines

|see also=

}}

{{Commons category}}

{{reflist}}

• {{cite book |last= Gunston |first= Bill |title= World Encyclopedia of Aero Engines, 5th Edition |year= 2006 |publisher= Sutton Publishing Limited |location= Phoenix Mill, Gloucestershire, England, UK |isbn= 0-7509-4479-X }}
• {{cite book|last=Kay|first=Anthony L.|title=Turbojet History and Development 1930-1960 Volume 2:USSR, USA, Japan, France, Canada, Sweden, Switzerland, Italy and Hungary |publisher=The Crowood Press|location=Ramsbury|date=2007|edition=1st|isbn=978-1861269393}}

{{GE aeroengines}}

{{USAF gas turbine engines}}

J31

Category:1940s turbojet engines

Category:Centrifugal-flow turbojet engines