X-6

IIRC jet propulsion works by ejecting exhaust gases that push on the air behind the engine and this thrusts the engine/aircraft forward. Am I right? Note this is unlike a rocket egine which works on the equal and opposite reaction principle and doesn’t need anything (air) to push against.

No you’re not. The jet engine works on the principle that a mass of gases is accelerated by the engine, and because of the equal and opposite reaction principle (Newton’s third law?) this creates a propulsive force. The main difference between a jet and a rocket engine is that the jet needs air containing a significant amount of oxygen for combustion, while the rocket engine carries its own oxygen as well as the needed fuel.

Just as we cannot push against air with our hands, a jet engine has the same problem :rolleyes:

http://forum.airforces.info/showpost.php?p=519223&postcount=24

I’ve got some images of this project in a book about GE, basically it is indeed a twist on a jet engine, keeping the compressor and turbine sections, but replacing the combustion chambers with what is basically a heat exchanger, adding heat from the reaction process to the compressed air that flows through the engine. For size/available energy reasons the unit was designed to have two ‘jet engines’ with one reactor feeding them both.

While the X-6 is connected to this project, it never flew with any of these engines. The purpose of the X-6 was to examine the problems of handling a nuclear reactor in flight, looking at shielding for the crew, airframe problems, handling etc. To do this it was modified to carry a small nuclear reactor in the bomb bay which could be powered up, but did not deliver any power/energy to the aircraft itself.

If I understand what TurboNZ’s saying – it’s a twist on a “regular” jet engine. IIRC jet propulsion works by ejecting exhaust gases that push on the air behind the engine and this thrusts the engine/aircraft forward. Am I right? Note this is unlike a rocket egine which works on the equal and opposite reaction principle and doesn’t need anything (air) to push against. So is this engine replacing exhaust gases with a stream of high pressure air (and creating that pressure by heating it)?

There’s a picture of a nuclear turbine in Bill Gunston’s Encyclopedia of Aircraft Engines.
It looks like two side-by-side jet engines with a lump, presumably the reactor, between them.
I’ve looked at the picture and read the brief description several times but it still hasn’t sunk in. I’ll have another look and see if I can understand it.

Here’s part from a website which goes a little way into explaining –

By early 1951, the Air Force had concluded that the NEPA project had shown enough promise that work should begin on an actual propulsion unit. General Electric was the prime propulsion contractor. The system would work by having air enter a compressor, where it would be heated by passing through the reactor, and be exhausted through a jet nozzle. Pratt and Whitney was given a contract for the development of an indirect cycle engine which would use an intermediate fluid to transfer the heat to the air rather than by passing the air through the reactor core itself.

(Source – http://home.att.net/~jbaugher2/b36_14.html)

Hope this helps 🙂

Cheers
TNZ