Making Bad Designs Good

[KJ_Lesnick]

tomo pauk

Radiator for engine cooling was in one wing, oil cooler was in another.

And is the intercooler radiator the same as the engine radiator, or the oil-cooler?

BTW, in the talk about Airacuda, you've mentioned that G limit on the A-20 was 3,something. Such was also for the Airacuda -perliminary limit was +3.4 G, ultimate +5.6 G. As a fighter, it was a turkey.

That is bad

As a what if - maybe reverse the engine and gunner stations front-to-back, so the gunners became rear gunners?

Why not just have a single pilot, a sturdier airframe, a smaller wing to go with the reduced weight, and the 2 x V-1710 as a starting point?

The Airacuda carried max of 800 gals of fuel (!) in the wings, even with providing them with self-sealing will not steal much.

Now that's a respectable amount of fuel!

[wuzak]

tomo pauk

Radiator for engine cooling was in one wing, oil cooler was in another.

And is the intercooler radiator the same as the engine radiator, or the oil-cooler?

No.

[tomo pauk]

And is the intercooler radiator the same as the engine radiator, or the oil-cooler?

Nope. In the P&W 2-stage installations, there were 2 intercoolers per engine, located just behind the engine, asides of the supercharger casing. One, numbered as item 145, is titled as 'blower radiator'.
https://s-media-cache-ak0.pinimg.com/originals/b9/2a/21/b92a21e47da7dcb5d23554d48d654961.jpg
On this pic of the Hellcat with cowling removed, the intercooler is housed in the yellow-ish fairing, each of the intercoolers fed by own cheek intake (the in-between intake providing the air both for oil cooler and engine combustion)
https://farm6.staticflickr.com/5286/5322845418_acd88cf073_b.jpg
The P-47 used a single intercooler, a 'box' tilted some 40 degrees, situated between the pilot and turbo.

Why not just have a single pilot, a sturdier airframe, a smaller wing to go with the reduced weight, and the 2 x V-1710 as a starting point?

For a what if - everyting works.
In reality - that is a whole new aircraft. The wing was already 50% bigger than on the Mosquito or A-20, two V-1710s won't cut it even of we reduce the size of Airacuda to the size of the Mossie or A-20, at least not for fighter duties; it will be bigger than the Bf-110, for example.

I'd propose another bomber out from the Airacuda - two V-1710s in tractor layout, 3rd engine in fuselage, just behind the wing, to power the pusher prop akin to Do-335. Tricycle U/C is a must, the fin & rudder projecting downward instead upward (outfitted with a small wheel, acts as a bumper to save the prop from damage on landing & take off). A proper bomb bay is needed, too, for at least 2 x 2000 lbs in tandem.
Nacelle guns/turrets, maybe steal them from the B-26.

[jcf]

I'd propose another bomber out from the Airacuda - two V-1710s in tractor layout, 3rd engine in fuselage, just behind the wing, to power the pusher prop akin to Do-335. Tricycle U/C is a must, the fin & rudder projecting downward instead upward (outfitted with a small wheel, acts as a bumper to save the prop from damage on landing & take off). A proper bomb bay is needed, too, for at least 2 x 2000 lbs in tandem.
Nacelle guns/turrets, maybe steal them from the B-26.

Ummm, that makes zero sense as adding an engine with pusher drive-shaft to a tail mounted prop would eat into
any possible bomb-load.

Sorry folks, the Airacuda design was a complete and utter turd and nothing you can suggest can save that POS.

[KJ_Lesnick]

wuzak

No.

Okay, I knew normally they weren't the same but with the P-39 I was kind of uncertain


tomo pauk

Nope. In the P&W 2-stage installations, there were 2 intercoolers per engine, located just behind the engine, asides of the supercharger casing. One, numbered as item 145, is titled as 'blower radiator'.
https://s-media-cache-ak0.pinimg.com/originals/b9/2a/21/b92a21e47da7dcb5d23554d48d654961.jpg

I would have just thought that it had to do with the nature of the air-intake for the particular aircraft (F4U had two intakes)...

In reality - that is a whole new aircraft.

It is a rework at the conceptual level: Based around revising the baseline concept around something that's practical.  Admittedly it would largely amount to a different design.

BTW: Do you have any idea where the fuel-tanks were located in the aircraft?

[tomo pauk]

The location of fuel tanks can be easily seen in different cutaways forund on the internet. Also, for the aircraft in the US Navy service, there is plenty of SAC, CS and ACP documents here: http://alternatewars.com/SAC/SAC.htm - a great resource indeed. I'd also recommend a book, the 'America's hundred thousand' by. F.H. Dean, a real treasure chest.
The F4U have had 2, 3 or 4 intakes, depending on the variant; all were with 2-stage R-2800 with 2 intercoolers. Location of fuel tanks changed with versions.

Ummm, that makes zero sense as adding an engine with pusher drive-shaft to a tail mounted prop would eat into
any possible bomb-load.

The much heavier (and with much more power) engines made the A-20 carry more than DB-7, the Wellington with two heavier Hercules engines was a better bomber than with Pegasuses. Problem with Airacuda was that it was too big for engine power, the wing's size was inbetween of early and later B-26, with just ~60% the engine power as the Marauder. It was also 60% of Marauder's weight, plenty of that will be eaten with bigger power installed.
Granted, in real world, going out with the 3rd engine would not be a trivial excersise.

Sorry folks, the Airacuda design was a complete and utter turd and nothing you can suggest can save that POS.

As-is - yes, it was a turd.

[JayBee]

I am surprised that nobody has yet suggesting fitting longer wings to make a bad design good. It seems logical to me. 

[PR19_Kit]

I am surprised that nobody has yet suggesting fitting longer wings to make a bad design good. It seems logical to me. 

I'd have thought it was blatantly obvious myself................ 

[Rheged]

I am surprised that nobody has yet suggesting fitting longer wings to make a bad design good. It seems logical to me. 

I'd have thought it was blatantly obvious myself................ 

We were all wondering how long it would be before you said that!

[PR19_Kit]

I am surprised that nobody has yet suggesting fitting longer wings to make a bad design good. It seems logical to me. 

I'd have thought it was blatantly obvious myself................ 

We were all wondering how long it would be before you said that!

I try and avoid these endless threads as much as possible............. 

[KJ_Lesnick]

tomo

The location of fuel tanks can be easily seen in different cutaways forund on the internet.

I guess it's easy that a mix-up would occur: I meant the XFL-1

Also, for the aircraft in the US Navy service, there is plenty of SAC, CS and ACP documents here: http://alternatewars.com/SAC/SAC.htm - a great resource indeed.

Yeah, tell me about it...

The F4U have had 2, 3 or 4 intakes, depending on the variant

F4U-1 and F4U-4.

As for the turbocharged variants, why were they cancelled?


JayBee

I am surprised that nobody has yet suggesting fitting longer wings to make a bad design good. It seems logical to me. 

I know I come off humorless, but that one made my day

[tomo pauk]

Turgocharged variants of the F4U were probably not needed.  For the intakes of the F4U and fuel tanks of Bell's aircraft - time to do some homework ?

[KJ_Lesnick]

joncarrfarrelly

Sorry folks, the Airacuda design was a complete and utter turd and nothing you can suggest can save that POS.

Oh, but you would be wrong: If you modify something enough times, eventually after enough transformations it becomes something that has a possibility of working

This is the design, and as a basic start





And start the basic frame around two basic features

• The front of the nacelle and it's very streamlined shape
  
• The profile which has a very teardrop configuation
  

.
Then basically do the following

• Some diagrams (the bottom two) depict what looks like a rear-window for a ventral gunner position; others appear to be a more streamlined teardrop shape: Adopt the more tear-drop shaped arrangement
  
• Remove the window at the top-mid fuselage position, as well as the waist-gunner blisters, windows/doors: No need for them in this design
  
• Use the front of the nacelle and it's gunner-window as the aircraft's basic fuselage-forebody and cockpit-section
  
• Shrink the aircraft around or near the depth of the front of the nacelle-nose: I'm unsure about width, but this will almost certainly shrink the plane to a degree, though I don't know to what extent
  
• Remove the wings and fillets: The wings are far too big for the design and the wings are dependent on the fillets, I'll get to this later
  
• Redesign engine nacelle: Obviously the design will not be a pusher for starters; secondly, the design will not have to include a crew-section for a gunner, or far as I know, a 6-inch extension shaft.  The engine, the turbocharger and the associated intakes, ducting, and radiators will be all that's required.  Spacing between aircraft and fuselage seem okay
  
• Replace old wing with a thinner design, aspect ratio around 7.1-7.2, wing area around 390 square feet and new fillets to go with the design: It should yield a wingspan around 52-53 feet based on the calculations.
  
• Remove bomb-bay: The idea of dropping bombs on bombers is frankly idiotic, unless you of course have a rocket-engine tied to the back of them with movable fins and a streamlined nose-cone with a guidance system (aka a missile), but since that really wasn't such a practical idea in 1937 -- it seems best to just go with the guns and cannon.  Hardpoints could always be added under the wings for targets on the ground if need be
  
• Oh, and just redesign the entire structural configuration underneath since the design wasn't sturdy enough: If possible join the spars with the stringers, and use multiple spars if you got to
  

.

tomo pauk

Turgocharged variants of the F4U were probably not needed.  For the intakes of the F4U and fuel tanks of Bell's aircraft - time to do some homework ?

I'm curious where you're going with this?[/list]

[wuzak]

• Remove bomb-bay: The idea of dropping bombs on bombers is frankly idiotic, unless you of course have a rocket-engine tied to the back of them with movable fins and a streamlined nose-cone with a guidance system (aka a missile), but since that really wasn't such a practical idea in 1937 -- it seems best to just go with the guns and cannon.  Hardpoints could always be added under the wings for targets on the ground if need be
  [/list

Are you aware that the Germans actually dropped bombs on 8th AF formations?

Certainly they did so during one of the Schweinfurt missions.[/list]

[Hobbes]

• Exhaust Stack: Where it would normally be expelled into the airflow, but being that this is a turbo; the exhaust gasses end up driving a
  
• Bucketwheel: A turbine which is driven by the exhaust gasses from the engine; the turbine is cooled from the (somewhat warmed) air that was used for the intercooler; the airflow is then routed to the...
  
• Wastegate: Who's job it is to regulate the RPM of the turbocompressor.  After this point, the exhaust parts ways with the aircraft
  

That should be the other way round. The waste gate sits before the turbine. When it opens, air can bypass the turbine, reducing the amount of power going into the turbocompressor and limiting intake pressure.