Well's Somthings not right in mudsville.

[hitech]

 

F4u-1C/D:

3G stall speed: 150 knts IAS (176 mph CAS, +3 knts)
Turn radius: 224m (70 degree bank)
Tested in AH: 30s @ 130 mph = 278m

3G radius corrected to 130mph/1.64G/52 degree bank = 266m
Error = 5%

P-51D:

3G stall speed: 159 mph IAS (162 mph CAS)
Turn radius: 190m (70 degree bank)
Tested in AH (75% fuel, no fuse tank):
27s @ 150 mph = 288m

3G radius corrected for 150mph/2.57G/67 bank = 194m

Error = 48%

P-38L:

3G stall speed: 170 mph IAS (175 mph CAS)
Turn radius: 221m (70 degree bank)
Tested in AH: 26s @ 160 mph = 296m

3G radius corrected for 160 mph/2.51G/66 bank = 226m

Error = 31%

Off the 3g stall numbers on a P51 did a quick Max LCO calc on the stang.
With a weight of 9600 Lb's and an area of 234 sqr feet I come up with a max lco of 1.9 This dosn't sound like a clean configuration.

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HiTech
For Bribes

[This message has been edited by hitech (edited 06-05-2000).]

[RAM]

sorry for those as me that dont know what's that...that means that the turning radius of the P51 is bigger than it should be?...

Damn it, I am letting the Fw190 for the P51 again  

[Nash]

Yah... Any of you nerds wanna translate that for us?    

edit---

er.. Not meaning HTC. If youve participated in the Turn Rate Is Hosed thread, you qualify.

[This message has been edited by Nash (edited 06-05-2000).]

[Yeager]

Yes Bazil, but what does it all mean?
====
International fan of misery

Yeager

[Zigrat]

Lift coefficient is a good measure of the amount of lift generated per unit area by the wing. For an ideal, infinite span airfoil, the maximum slope of the Cl/alpha curve is 2*Pi/alpha in radians or about .11 per degree. HT saying that the maximum lift coefficient of the P51 is about 1.9 means that the mustang turns BETTER than it should. I dont know the specifics of the pony wing, but it likely stalls somewhere around 16 degrees AOA. It has camber, so its  angle of zero lift is probably around -3 or 4 degrees AOA. And, for class i had to do an analysis of a wing planform not too unlike the pony (though not exactly the same) at about .078 per degree, which would give the pony a max LC of 1.56. IE the mustang turns too well  

[RAM]

 

Originally posted by Zigrat:
HT saying that the maximum lift coefficient of the P51 is about 1.9 means that the mustang turns BETTER than it should.

Ahem...who was the one saying that Fw190 turns like a P51?


         

hhihihihihihi

[Vermillion]

Ummm... who actually turns a Pony anyways   ?

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

[Pongo]

Spitfire too spitfire too!


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"Stupids are like flies. they are everywere, but are easy to kill"
RAM

[Minotaur]

The P-38 has an error of 31%, does that mean it turns too good also?

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Mino
The Wrecking Crew

[Zigrat]

btw anyone know the naca code of the airfoil used in the p51 wing? I know they attemped to delay boundry layer transition(to turbulent flow), but im not sure what method they used. My guess is they pushed the position of max thickness/chord rear to reduce the adverse pressure gradient over the majority of the airfoil. This would probably also mean that camber was slight and angle of zero lift would be more like - 2 degrees than -4. So that numberI gave earlier might even be a bit high, but effects such as lift generated by the fuselage might cancel it out.

[F4UDOA]

Would somebody please pay attention to me on this subject. The max lift coefficient of the P-51 is seen as aircraft A in this NACA document.   http://naca.larc.nasa.gov/reports/1945/naca-report-829/index.cgi?page09.gif  
It is in fact approximately 1.50 no flaps.
Full flaps it is 1.89 the F4U is 1.88(reduced from 2.33 and also 1.48 with no flaps with the addition of the wing spoiler). You can see this clearly in the full document.

Thanks
F4UDOA

I am the Rodney Dangerfield of Aces High

[This message has been edited by F4UDOA (edited 06-05-2000).]

[This message has been edited by F4UDOA (edited 06-05-2000).]

[This message has been edited by F4UDOA (edited 06-05-2000).]

[hitech]

Gents: i'm not talking about our stang having wrong numbers. The 3g stall wells is talking about was some test that were done.

From this testI calculated a max lift co.

Like anything numbers in isolation ,i.e 3g stall,with out the other items don't realy give you much information.

My guess is that they did a 3g stall test with flaps down and hence wells descrepency between us and them.



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HiTech
For Bribes

[Zigrat]

ah cc hitech i just figured it out and the numbers in the aces high test correctate pretty well with a max CL of around 1.5, which is what should be expected for the p51, nice to see that theory actually works in some cases  

[Hangtime]

"Ummm... who actually turns a Pony anyways?"

LOL... I do.  

Hang

[Downtown]

I got a couple of former NASA guys at work I might be able to run this stuff by, I know I got an Aerospace engineer that can look at it.

I don't know any former North American types or test pilots to ask.

HT I wish you would have used the <> in your %'s so we would know if they were greater or lesser %'s


RAM,

According to the numbers above, you shouldn't be turning a pony at all.  I got burned by Hogs making S turns a couple times, this will make it worse!

Zig what are you Aerospace, Aeronautical Engineering, or just read too damn much?

F4UDOA, you Gif didn't come out right.

I know I can find the NACA for the P-36 and P-40 airfoils, but like I said I am bereft of North American Stuff.


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"Downtown" Lincoln Brown.
    lkbrown1@tir.com    
 http://www.tir.com/~lkbrown1
Wrecking Crews "Drag and Die Guy"
Hals und beinbruch!