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Search Results : XNJ140E

XNJ140E part 3

Dec 302012

No point in developing a nuclear powered turbojet if you don’t have some sort of idea what you’re going to put it in. In the case of the XNJ140E, three of them were to power the Convair NX2. The NX2 was a research aircraft based on prior design work for a subsonic nuclear powered missile carrier, the Model 54 (not a “bomber,” per se, as it had no internal bomb bay and carried powered missiles rather than gravity bombs).

Numerous variants of the NX2 were designed, taking advantage of different nuclear turbojets. The design shown below used three XNJ140E’s to provide cruise propulsion; but for takeoff, two additional chemically fueled turbojets were provided in underwing pods.

The configuration was an unconventional canard layout. This had the advantage of letting the engines occupy the tail of the aircraft, clear of entanglements with wings or stabilizers. After landings the engines could be relatively easily removed from the aircraft for servicing and storage.

XNJ140E part 2

bomber, nukes, research 2 Responses »

Dec 272012

A layout illustration of the General Electric XNJ140E-1 nuclear turbojet. This is the developmental engine, not an operational engine, and does not seem to have a chemical afterburner.

XNJ140E part 1

bomber, nukes 5 Responses »

Dec 252012

The General Electric XNJ140E nuclear turbojet was proposed in March 1960 to meet then-current DoD guidelines for the nuclear aircraft program. It utilized a single X211 turbojet mated to a beryllium oxide reactor, a change from the prior XMA-1 engine standard which had one reactor powering two X211 turbojets. Ground test for the XNJ140E was scheduled for December 1962, with flight testing to begin in a Convair NX-2 in 1965.

The XNJ140E was designed for a lifespan of 1000 hours under power, at which point it was to be removed from the aircraft and overhauled. The XNJ140E-1 was to be the developmental model, and would have had an estimated dry weight of 60,600 pounds. Of that, 18,320 pounds were turbojet, while 42,230 pounds were reactor, shield and controls.

The reactor assembly was 33 inches long and 62 inches in diameter, formed from 25,000 hexagonal tubes made from yttria-stabilized beyllia containing uranium. Peak operating temperature was to be 2530 degrees F. The reactor was capable of at least 121 megawatts for a nuclear-only runway takeoff, providing 35,310 pounds of thrust at Mach 0 and at sea level. For cruise at 35,000 feet and Mach 0.8, 50.5 megawatts would provide 8,120 pounds of thrust.

B-52G Nuclear Turbojet Testbed

bomber, nukes, research No Responses »

Dec 142012

Previously shown but not understood HERE, in 1961 GE proposed modifying a B-52G to serve as a testbed for a single XNJ140E-1 nuclear turbojet. The very large engine would be contained in a nacelle attached to the port rear fuselage. With eight conventional J57 chemical turbojets, the testbed aircraft would be capable of putting the engine through the altitude and airspeed paces that would be expected of it in the NX-2 nuclear powered bomber demonstrator (35,000 feet and Mach 0.8). This configuration would be capable of sustained nuclear flight.

Another configuration would have a second XNJ140E-1 nuclear turbojet on the other side of the fuselage, and only four J57’s. This aircraft would be capable of pure nuclear flight from takeoff to landing, with the J57’s as emergency backup.

Approximate isodose lines around the nuclear B-52G in powered flight