Whiffs found surfing

[chrisonord]

I like that,  I  think it needs to be made by someone. 
Chris

[jcf]

Looks a lot like the Bell XP-83:

[PR19_Kit]

But with Spitfire wings and a fin from something else.

Does anyone do a kit of the XP-83?

[kitnut617]

Does anyone do a kit of the XP-83?

According to the PAK-20 book, an outfit called KR Models did a vacuform of it back in the 80's.  But I seem to remember there's another outfit too, it appeared after the XP-59's did. EDIT: it was Anigrand   

https://modelingmadness.com/scott/korean/preview/anigrand/aa2054preview.htm

https://www.scalemates.com/kits/kr-models-bell-xp-83--266754

[PR19_Kit]

Hmm, good links there Robert, thanks. 

I'm tempted, but the $48 for the Anigrand kit causes some pause for thought.

[NARSES2]

Yup I've built the Anigrand kit and it's a big aircraft.

The photos were on here at one stage but they got culled when we had to do away with direct posting of photos.

[Weaver]

Posted on Twitter by Trev Clark @TrevClark1958 here: https://twitter.com/TrevClark1958/status/1199269157457530880?s=20

I'm really a fan of the 1950's aviation scene, a time when
anything was possible...or so it seemed. How about an atomic
powered aircraft, with a flyable escape module should the
reactor fail. Doesn't warrant even thinking about today, but back
then, why not put it forward?

[Tophe]

  I knew this twin-boom project, thanks to remind it. The position of the cockpit at the top of the tail is wonderfully unusual (like on an Airspeed twin-boom propeller plane).
I am surprised by the word "refueling": I thought that, like on a submarine (or aircraft carrier ship) with nuclear reactor, the range was several times around the World and refueling happens only once a year or two years, no?

[kerick]

Posted on Twitter by Trev Clark @TrevClark1958 here: https://twitter.com/TrevClark1958/status/1199269157457530880?s=20

I'm really a fan of the 1950's aviation scene, a time when
anything was possible...or so it seemed. How about an atomic
powered aircraft, with a flyable escape module should the
reactor fail. Doesn't warrant even thinking about today, but back
then, why not put it forward?

In case you wondered where Gerry Anderson got his ideas!
Thanks for posting this!

[NARSES2]

Interesting Harold 

Mind you I have never been able to grasp how a nuclear powered aircraft would work ? Many people have explained it to me, but my brain just won't or can't deal with it for some reason ? 

[Tophe]

I have never been able to grasp how a nuclear powered aircraft would work ? Many people have explained it to me, but my brain just won't or can't deal with it for some reason ? 

It seems a jet with jet exhaust, but without fuel nor kerosene to explode and eject on the rear, I also don't know what the heat of the nuclear fission would do on this air at high speed.

[Weaver]

Interesting Harold 

Mind you I have never been able to grasp how a nuclear powered aircraft would work ? Many people have explained it to me, but my brain just won't or can't deal with it for some reason ? 

Well instead of using burning fuel to heat up the air in your gas turbines, you use the heat from the reactor instead. There are, broadly, two ways of doing this:

Direct Cycle.
This is where the intake air is passed directly through the core of the reactor, cooling it and getting heated up in the process.
Upsides: lowest weight, highest heat transfer, relatively simple.
Downsides: highly radioactive exhaust.

Indirect Cycle.
This is where the reactor is cooled by fluid in a closed, regenerative system, where the heat exchanger that cools the fluid heats the intake air.
Upsides: less radioactive exhaust.
Downsides: higher weight, lower efficiency, higher complication.

[Tophe]

Thanks for the explanation, helping me a little understanding.
But my understanding is not complete: a jet principle is not (according to my little knowledge) based on "heating up" air. The principle is a violent explosion, directed rearward. For the rocket engine, the front end is closed, no air but liquid oxygen or other oxidizer chemical. For a turbojet, the oxygen for the explosion is provided by compressed air, the rest is the same. Heating air seems not enough, without explosion, to make a big speed, yes?
That possible legend of heating air (for hiding the secret Truth? what-if...) reminds me the mistake of René Descartes, the inventor of the Cartesian spirit (pretended to be logical): he said he proved that the heart (on humans and animals) is a heating machine, transforming cold blood into warm blood, which makes it move. Now biologists say this was all wrong, the heart is a mechanical pump with valves. So, is the nuclear air jet just a heating machine? Maybe... or what-if it was different?

[Weaver]

Fuel in a jet engine doesn't 'explode', it 'combusts' i.e. 'burns'. (Exploding and burning are not the same thing.)

A jet engine works because the burning fuel raises the temperature of the air, which, since it's in a confined space, raises it's pressure. It's the pressure difference between the cold air going into the intake and the hot air going out of the exhaust that pushes a jet aircraft along (pure turbojet, not a turbofan).

So yes, a jet engine does work by 'just' heating up the air, and so will work with an alternative source of heat. Remember the Project Pluto nuclear ramjet, that was designed to the point where they could have started building it? Well that worked by ramming air through the middle of a nuclear reactor to heat it up: no explosion, just lots of heat.

A nuclear turbojet aircraft is less efficient than a fossil fuel one for a few reasons:

1. Nuclear reactors run at lower temperatures than burning jet fuel. The latter can reach temperatures of nearly 1600 deg C, while the hottest reactors run in the high 900 deg C range and most are lower than that. Note that the early jet engines around in the days when the US nuclear aircraft program was started only had a combustion temperature of around 800 deg C, so nuclear looked competetive with that.

2. Less heat is transferred to the air, mostly because of the difficulties of designing an efficient heat-exchange arrangement between the intake air and the reactor or it's coolant.

3. The extra weight of the reactor and it's shielding reduces the power:weight ratio of the aircraft as a whole.

However it's big advantage is endurance, since the reactor will produce heat constantly for years, rather than the hours which any practical amount of kerosene tankage would last for.


Wiki entry on aircraft nuclear proplusion explains it nicely: https://en.wikipedia.org/wiki/Aircraft_Nuclear_Propulsion

J-87 direct cycle engine: https://en.wikipedia.org/wiki/General_Electric_J87

[Tophe]

Thanks for the extra explanation, now it is clear for me I think.

Fuel in a jet engine doesn't 'explode', it 'combusts' i.e. 'burns'. (Exploding and burning are not the same thing.)

Maybe this comes from a translation issue: the English article
https://en.wikipedia.org/wiki/Reciprocating_engine
is in French
https://fr.wikipedia.org/wiki/Moteur_à_combustion_et_explosion
(engine with burning and exploding) shortened at secondary school as "moteur à explosion" (engine with exploding)...
Is exploding a word to say that the flame position moves at supersonic speed? maybe not even in a rocket engine... (I was wrong).