Radial engined fighters

[kitnut617]

Not saying it's impossible by any means, but one thing to bear in mind is that a lot a Wankels use a hollow "crankshaft" as a means to cool the rotors.

Not sure which Wankels are like that Weaver, because looking at various photos of the crankshaft from a Mazda (the most successful rotary engined cars) they're all solid steel.

[PR19_Kit]

Any minute now someone's going to suggest a 'moteur canone' fitted to a 4-shaft turbo-fan...........  

[Weaver]

Not saying it's impossible by any means, but one thing to bear in mind is that a lot a Wankels use a hollow "crankshaft" as a means to cool the rotors.

Not sure which Wankels are like that Weaver, because looking at various photos of the crankshaft from a Mazda (the most successful rotary engined cars) they're all solid steel.

Certainly Nortons and I think DKW Wankels ducted cooling air down the centre of the crankshaft, the Suzuki RE5 used oil cooling via the same route.

[kitnut617]

Not sure which Wankels are like that Weaver, because looking at various photos of the crankshaft from a Mazda (the most successful rotary engined cars) they're all solid steel.

Certainly Nortons and I think DKW Wankels ducted cooling air down the centre of the crankshaft, the Suzuki RE5 used oil cooling via the same route.

Those were a couple of early designs though, looking at the part break down of the Mazda, the rotors themselves are hollow but they also look like they are made from some other material rather than steel, it's got a very black look to it.  I can see that running air through the rotors would do as you say (or oil) as almost every jet engine has compressed air running through the hot section turbine blades to keep them cool.

[kitnut617]

Any minute now someone's going to suggest a 'moteur canone' fitted to a 4-shaft turbo-fan...........  

Think there would be a serious gun-gas ingestion with that Kit

[Dork the kit slayer]

.....all that being said. Its what if and if you want a radial or twin radial firing through the prop boss..well go for it. Who knows what is possible in your dimension.
Its the beauty of What if,its a very broad church.


Things are so so much easier when details dont get in the way.

[PR19_Kit]

Any minute now someone's going to suggest a 'moteur canone' fitted to a 4-shaft turbo-fan...........  

Think there would be a serious gun-gas ingestion with that Kit

You could have a VERY long barrel............ 

[rickshaw]

Any minute now someone's going to suggest a 'moteur canone' fitted to a 4-shaft turbo-fan...........  

mmm, the gun might get a wee bit hot.  It would either have to be behind the exhaust or in the middle of the engine.  However, apart from the already mentioned gas ingestion problem, in theory it would be possible in an axial flow engine - afterall, everything is in a straight line around a series of concentric shafts, so if you can fix the gas ingestion problem and the heat problem, it'd work I think.  

I wouldn't want to try it with a centrifugal flow engine though.  

Much easier, with any of these sorts of alternative powerplants (to an inline piston engine)  to offset it and have the cannon firing through an eccentric propeller driven by a gear box.  You could even use a rotary engine that way.

Here's a though, is an axial flow jet a radial or a rotary engine? 

[PR19_Kit]

<snip>

I wouldn't want to try it with a centrifugal flow engine though.  

<snip>

Here's a though, is an axial flow jet a radial or a rotary engine? 

Actually it may work better with a centrifugal flow jet. There's a big space in the middle between the angled combustion chambers where the breech of the gun could go, suitably insulated of course. And the centre of the compressor doesn't have to be solid, it could be a tube for the barrel with the air entering around it via a larger tube.

I'd say an axial flow jet is a rotary as there's nothing happening in a radial direction except the loading of the various blades. All the air flow and combustion happens longitudinally and the bits in the middle are rotating like CRAZY! 

[pyro-manic]

What about switching the engine and the ancilliaries (oil tank, fuel tanks etc) around, so the engine is up against the firewall immediately in front of the cockpit, and all the other gubbins are forward of it, between engine and prop? There could be space for a gun firing through the shaft then. Might make for some interesting weight distribution issues though. Or do a P-39 and have a mid-mounted radial with some clever ducting for cooling.

[Hobbes]

You'd need some mechanism to transfer the trigger from the stationary part of the gun to the rotating barrel.

[deathjester]

How about a mid - engined fighter where there is a gatling gun mounted in the prop spinner, so the engine rotates the barrels?

[PR19_Kit]

You'd need some mechanism to transfer the trigger from the stationary part of the gun to the rotating barrel.

Slip rings should do that alright, it was established technology on steam engines.