2's Better than 1

[Charl]

So what might you pick, on a lazy Saturday, to steal the show from those ol' Warbirds?
It would have to have a sassy name, like "Stratojet Merlin"
Would have to be powerful, perhaps tuck a pair of big V12's one behind the other driving contra-rotating props (Oops! they're not Merlins! Allison V-1710's then, they'll do).
Perhaps paint it full of stripes, lots of stripes.
Two seats so you could talk the talk afterward, and know there was a witness...



Power? Let's put it this way - switch off one motor, and see if it takes off OK and cruises 250kts. Tick.
With two fans turning, 450kts and overspeed is easy, zoom is up to 30,000ft


Very docile handling becausue of canard configuration, cruises high or low.


Model: Stratojet Merlin by Eugene Heyart
File: sj_mer_2.zip
Custom Paint by yours truly

How could I ever bring my Long-EZ here, after this??

[Ian Warren]

JEEPERS , let hope its not a Dogfight with that poor Corsair taxing in the background , dang ... looks like the big daddy to the EZie

[Bazza]

Bert RUTAN on steroids ?

[Timmo]

two engines but one prop?

[Alfashark]

Contra-prop setup

Just the trick for getting the mind working once you start trying to figure out reduction gearing and coaxial output shafts...

[ZK-LGD]

Oh! My! Gosh! It's a Hughes Aviation Bloodhawk from the arcade game Crimson Skies!!!

[Timmo]

QUOTE (Alfashark @ Apr 26 2008, 11:37 PM) <{POST_SNAPBACK}>

Contra-prop setup

Just the trick for getting the mind working once you start trying to figure out reduction gearing and coaxial output shafts...

Yeah thats what I was assuming....but it doesnt look like its modelled? I can only see one 'line' of blades on first cone?

[Charl]

Yeah sorry I was having a look at the single-engine performance which is misleading.
Here's the deal:

It's such a sweet solution - no torque reaction, even though there's a couple of thousand horses driving the thing!
And no yaw with one engine out.
Totally docile axial behaviour, no barrel roll - you flick the ailerons, it turns like a power screwdriver.
Why aren't all twins made this way?
I think AS has a point: taking the front drive past the rear engine may be a dealbreaker...

[Alfashark]

Hmmm, I'd imagine there'd be a electro-hydraulic coupling between the output shaft of the number 1 engine (the front one, output shaft facing rearwards) and the blower drive shaft on the number 2 engine. Then a master reduction box and counter rotation unit using shaft inside shaft on the output end.

I may be wrong... who knows

I may stand to be corrected, but I'm sure one variant of the de Havilland Gypsy Queen engine drove its reduction box via a Quill flexible shaft drive, since the installation resulted in the output shaft facing rearwards, but needed to drive a tractor propeller...

[yak52dude]

that thing looks a lot like a xp-55 acender