Tractor/Pusher

[PR19_Kit]

16000 hp worth of piston engines?

That's got to have been LOUD, let alone anything else, but I've loved to have heard it.  

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

[NARSES2]

16000 hp worth of piston engines?

That's got to have been LOUD, let alone anything else, but I've loved to have heard it.  

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

Wasn't it the Thunderscreech that made people sick on the ground because of the noise it's prop made (or maybe it was the vibration ?)

As for props in the middle. there are some nice looking designs I must admit. I've got the Unicraft BMW kit in the stash and I seem to remember some resin kit of a Japanese design in there as well ? Although that may be just a pusher, I'll have to dig into it a bit and find it.

[PR19_Kit]

16000 hp worth of piston engines?

That's got to have been LOUD, let alone anything else, but I've loved to have heard it.  

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

Wasn't it the Thunderscreech that made people sick on the ground because of the noise it's prop made (or maybe it was the vibration ?)

As for props in the middle. there are some nice looking designs I must admit. I've got the Unicraft BMW kit in the stash and I seem to remember some resin kit of a Japanese design in there as well ? Although that may be just a pusher, I'll have to dig into it a bit and find it.

It was the XF-84H that made people sick on the ground, yes. The prop was so small that the tips went supersonic at anything above ground idle which made the most horrendous noise apparently. 

[jcf]

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

Evidently it worked well enough on the Gallaudet D-1 and D-4.

[kitnut617]

The radiator/oil cooler? intakes look familiar but I cannot place them. That's about all I can pick besides the MiG-29 basis.

Well the radiator ducts come right off a F-82 which is why perhaps they look familiar, and although I did use a Mig-29 for the most part, I needed a deeper fuselage at the rear to house the engines. So from just in front of the windshield back to the rear prop spinner and about half way down the fuselage sides and then including the canopy and cockpit interior, it's all BAe Hawk ------  Another reason I wanted a deeper fuselage especially at the rear end, was to raise the rear props upwards so there is prop clearance during take-off rotation. Props came from an XB-35. I'm going to use the Mig-29 undercarriage which had to be lengthened a bit and it will have retractable skid bumpers under the tail booms as a safety measure against possible prop strikes with the ground during take-off. I had to widen the tail booms so they cleared the prop tips but then I moved the outer wings forward too.

The idea is that the rear of each engine face each other, because this is where the exhaust augmenters are and the exhaust would then be piped to exit through the rear of the radiator ducts, using the exhaust and heat from the radiators as extra thrust (as the duct would work very much like the P-51 ducts do)

The prop Sabre and Meteor with low slung engines look really good too.

The prop Sabre is another Crecy X-24 design I came up with. The overall size of the X-24 with it's supercharger fixed to the front of the engine block and then an exhaust augmenter fixed to the rear, with the X configuration engine block in between them, are about the same size and diameter as a turbojet of the time. The F-86D airframe is designed for 8000 lbt and the Rolls Royce books I have on the Crecy and Mustang, both say a pound of thrust is about 1 hp, so as far as I can see, the airframe would work for an 8000 hp engine. Once again, the engine is in the rear right where the turbojet would be and drives a drive shaft to the contra prop which just happens to be from a Wyvern.

Undercarriage for it comes directly from an FJ-4 Fury without any modifications.



The idea is after the successful collaboration with North American and their Mustang, Rolls Royce modified the F-86D airframe for the Crecy engine (this is all assuming that turbojets took a lot longer to develop and problem to overcome). One of the design features of the X configured Crecys, was an annular radiator matrix that wrapped around the outside of the supercharger, my idea was the F-86D air intake would be used to take air to the supercharger and radiator, the ducting downstream of the radiator would continue rearwards, to exit around the exhaust pipe so would look a lot like the tailpipe of a jet.  The heated up air from the radiator would be used to cool the exhaust pipe, which in turn would heat up the exiting radiator air even more, so would create more thrust ----- that's the idea anyway ---  



The Meteor is actually one of the very first prototypes, which had the Metro-Vick axial flow engines installed. It was the second Meteor to fly, actually the prototypes were known mostly as Rampage [a code name] then and Meteor was only applied once the RAF got them into service. The Metro-Vick had about 4000 lb of thrust and were designed and built a long time before any German jet engine was known about or even looked at.

[PR19_Kit]

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

Evidently it worked well enough on the Gallaudet D-1 and D-4.

Sure, but might it have worked better with the prop at the front or the rear? It's not a question that can answered as no-one's ever built an aircraft in all three configurations, but it's interesting nonetheless.

[jcf]

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

Evidently it worked well enough on the Gallaudet D-1 and D-4.

Sure, but might it have worked better with the prop at the front or the rear? It's not a question that can answered as no-one's ever built an aircraft in all three configurations, but it's interesting nonetheless.

Dunno, based on the info in the link I posted earlier, in the case of the Gallaudet it may have been a wash as the fuselage diameter is 1/3 of the propeller
diameter and both the fuselage entry to and exit from the prop are actually pretty clean.

[wuzak]

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

Evidently it worked well enough on the Gallaudet D-1 and D-4.

Sure, but might it have worked better with the prop at the front or the rear? It's not a question that can answered as no-one's ever built an aircraft in all three configurations, but it's interesting nonetheless.

Dunno, based on the info in the link I posted earlier, in the case of the Gallaudet it may have been a wash as the fuselage diameter is 1/3 of the propeller
diameter and both the fuselage entry to and exit from the prop are actually pretty clean.

Might have a bit of wake off teh wings, though.

[NARSES2]

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

Evidently it worked well enough on the Gallaudet D-1 and D-4.

That's quite an attractive looking aircraft.

There's a couple of WWI period aircraft which started of as traditional tractor designs and then became mid engined after a fuselage extension was added in order to get a forward firing gun. The DH 9 which started this all off being one of them  Have we come full circle ? 

[jcf]

This thread makes me wonder about the practicallity of those 'prop in the middle' designs with the prop half way down the fuselage. that's got to have all the disadvantages of BOTH prop positions I'd have thought?

Evidently it worked well enough on the Gallaudet D-1 and D-4.

Sure, but might it have worked better with the prop at the front or the rear? It's not a question that can answered as no-one's ever built an aircraft in all three configurations, but it's interesting nonetheless.

Dunno, based on the info in the link I posted earlier, in the case of the Gallaudet it may have been a wash as the fuselage diameter is 1/3 of the propeller
diameter and both the fuselage entry to and exit from the prop are actually pretty clean.

Might have a bit of wake off teh wings, though.

Not as much as a thick-winged cantilever monoplane, the thin wings of the period are relatively clean in those terms.
The Spads got some of their speed from their superthin wings, which is why they had a two-cell rather than a single-cell
strut/rigging setup, which was unusual for a later WWI single-seat fighter.

Plus on the Gallaudet the wings are fairly far apart and of a relatively narrow chord, so I'd hazard the opinion that the
overall effect is less than one might assume.

BTW on the D-1 the powerplant was two Duesenberg 4-cylinder engines geared together, both were run for takeoff, and maximum
performance, but they could be declutched separately to allow cruise on a single engine. The D-4 used a single Liberty V-12.

I posted some unbuilt Gallaudet designs over in the old (2011) "Mid fuselage propellers" thread:
http://www.whatifmodelers.com/index.php/topic,33862.msg534740.html#msg534740

[NARSES2]

The Spads got some of their speed from their superthin wings, which is why they had a two-cell rather than a single-cell
strut/rigging setup, which was unusual for a later WWI single-seat fighter.

Often wondered why they had two-cell wings, now I know. Cheers Jon 

[Captain Canada]

Wild stuff in this thread ! Love that Galudet thing