Low alt performance of Big Planes in AH

[juzz]

The Spitfire is slower because of all the crap hanging out under the wings - "cooling drag".  

[-lynx-]

Niclas - that's how the ramjet works: air is entering one end of the tube, heated and expelled from the other at a greater velocity generating thrust. You can use fuel, radiator heat, even nuclear reactor (there was a prototype built in the States) to heat the air but the principal remains the same...

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-lynx-
13 Sqn RAF

[This message has been edited by -lynx- (edited 08-10-2000).]

[Jigster]

 

Originally posted by -lynx-:
Niclas - that's how the ramjet works: air is entering one end of the tube, heated and expelled from the other at a greater velocity generating thrust. You can use fuel, radiator heat, even nuclear reactor (there was a prototype built in the States) to heat the air but the principal remains the same...

So is it safe to say that "Roger Ramjet" got his name by farting?

Now how about d'em dummy scram-jets?  
(The engine or the bozos from NY; your pick)

- Jig who is in no way being serious.

[Duckwing6]

 

Originally posted by niklas:
f4udoa
Youīre right, planes like the cessna which are optimized for high speed and low drag have the wings 90° attached to the fuselage, while planes like modern jet airliner where low drag isnīt very important are build with wings swept back.

HAHAHAHAHAHAHAHAHAHAHAHHAHAH hihihihihihi huhuhuhuhu hehehehe MUAHHAHAHAhahaha

I've got tears in my eyes now really Niklas if that was a troll then a good one

DW6

[F4UDOA]

RGR That Funked, I'm out.

Jigster, stop that. You made me hurt myself.

Roger Ramjet, geez I can't stop crying.
Someone call the parmedics, I think I sprained my splean. Ouch it hurts.

Later

[CavemanJ]

 

Originally posted by F4UDOA:
Niklas,

214th.com is a gaming website. Do you have any more reliable historic data??

F4UDOA

yup, 214th.com as a whole is a gaming website.  I was the XO of VMFA214 BlackSheep that flew in the EIDOS CK beta, and that's our base of operations.  If you go through the sims section you can still see it.

HOWEVER

The WWII museum was put together with the best information we could compile on the aircraft.  I know, because I helped Widowmaker dig up all the information/pics/mpgs-avis.  The museum has been a work in progress for a long time, and I believe now officialy classifies as a hobby  

[Fishu]

 

Originally posted by funked:
Fishu - WATER INJECTION!!!

Okey... so this means german planes flies with steam engine.


A Sticker saying: "Reply to Funked"

[This message has been edited by Fishu (edited 08-10-2000).]

[niklas]

Duckwing, i didnīt thought it was necessary to add smilies to this sentencet ot show how i meant it  

wells, where do you have the drag area for the F4U from? Pls mail me the document.
I mean what if wells calculated this value? That would mean wells calculated from the 355mph value the drag area, and F4UDoa recalculated from the drag area back the topspeed and WHAT A SURPRISE itīs 355mph  

So when the F4U is so fast we get 2 basic conclusions for a high performance fighter design:
Heavy is better than light
Big is better than small

Indeed, the F4u  IS a revolution hihi  

niklas

[This message has been edited by niklas (edited 08-10-2000).]

[Vermillion]

Come on....

Everyone knows that "Old Man Vought" was actually an Alien.

And with that kind of technology, even pigs can fly.... errr ummm.... a Hog can fly  

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Vermillion
**MOL**, Men of Leisure
"Real Men fly Radials, Nancy Boys fly Spitfires"

[Jigster]

 

Originally posted by Fishu:
Okey... so this means german planes flies with steam engine.

I dare ya to make me explain water injection beyond the point of increasing manifold injection. Go on       punk       do you feel lucky?         do ya?

The effect is actually somewhat simular to a steam engine.

- Jig

[Fishu]

 

Originally posted by Jigster:
I dare ya to make me explain water injection beyond the point of increasing manifold injection. Go on       punk       do you feel lucky?         do ya?

The effect is actually somewhat simular to a steam engine.

Sorry.. forgot one thing...

*attachs "reply to Funked" sticker into the post*

[F4UDOA]

Niklas,

I have the stake for your heart.
I have the early war performance doc. exactly what is posted for various A/C on the 214th web site for the F4U-4 for the birdcage F4U-1 without water injection at a max 2000HP.

Here it is power loading listed at 6.8 so the HP must be at around 1700HP
military power
Vmax=395MPH at 23000FT.
Vmax at sea level=341MPH

Normal power about 1573HP power loading=8.9
Vmax at sea level with an external drop tank at 14000lbs=310MPH

Next the F4U-1D with water injection
12,039LBS power loading listed at 6.1 so we are talking 1973HP
Vmax=417MPH at 19900FT
Vmax at sea level=359MPH<===HELLO

At normal power
Vmax at 14000LBS with external drop tank=384MPH at 24600FT
Vmax at sea level with external drop tank 14000LBS=315MPH

Niklas even at normal power with an external drop tank at 14000lbs power loading at =>8.9<= the F4U is faster than you think it should be. How much more documantation would you like??  

Later
F4UDOA

[Badboy]

Hi juzz

 

Originally posted by juzz:
The Spitfire is slower because of all the crap hanging out under the wings - "cooling drag".  

Actually the Spitfire is slower by design. Nope, they didn't want it to be slow, but it was the price they had to pay for its superfluous manoeuvrability.  It turns out that the design criteria that produce high-speed aircraft conflict with those that produce highly manoeuvrable aircraft. So for example, aircraft that are manoeuvrable generally have a low wing loading, while aircraft that are faster have a higher wing loading. There are very good aerodynamic reasons for that and it was simply the case that when the Spitfire was designed, high manoeuvrability was thought to be more important.  That's why the Spitfire has elliptical wings for low induced drag and high sustained turn rates, and a low wing loading for high instantaneous turn rates. The penalty resulting from the low wing loading is paid for in the lower top speed. However, having said that, the Spitfire did have the highest dive speed, and got closer to Mach 1 in a dive than any other W.W.II aircraft.  

Badboy

[Badboy]

 

Originally posted by F4UDOA:
Niklas,

Here it is power loading listed at 6.8 so the HP must be at around 1700HP
military power
Vmax=395MPH at 23000FT.
Vmax at sea level=341MPH

F4UDOA

Ok guys, I see folk quoting drag coefficients, engine power and equivalent flat plate areas and making predictions about top speeds, but we can put this on a scientific basis, we can use those values to calculate the top speed.

I've done the math and the equation can be used to calculate the top speed given the data you guys have been quoting.

I've just tested it on the F6F-5 for example and given a peak prop efficiency of 83% from an engine delivering 2000HP and wings with an area of 334ft^2 and a Cd0 of 0.0223 the top speed at sea level clocks out at 320mph. I have a published value of 318, so the calculation has less than a 1% error.

Now don't lynch me because of my data… If anyone would like to post some data sets, I'll do the calculations and post the top speeds?

Data required is:

Prop Efficiency (e)
Altitude (h)
Engine Horsepower (hp)
Wing Area (s)
Zero Lift Drag Coefficient (Cd0)

The aircraft weight and induced drag are neglected, which result in a very small error, often less than 1%.

Badboy

[F4UDOA]

Badboy,

How's the research going, do you have anything to share?? When will you be publishing or disclosing your research?

What do you think about this topic? Is it impossible for a 12000lb A/C to fly 360MPH at sea level?

I just looked up the F7F stats on the 214th.com. It had a speed of 380MPH at 20,000lbs. at sea level. It must be full of helium I guess. Right Niklas?

Later
F4UDOA