Well's Somthings not right in mudsville.

[funked]

Don't forget that more than just the wing determines the lift of the aircraft.

[Ozark]

Please Funked!!! Let's not start with fuselage lift in the equation.   I just got pass prop theory by the skin of my tooth at FIT.  

Ozark

BTW: The toothbrush was invented in the Ozarks....If it was invented anywhere else, it whould have been called the teethbrush.  

[funked]

Don't forget that little wing back on the tail either...  

[F4UDOA]

Hey,

The image of the graph showing the max lift coefficient for the P-51 would not display so I posted the link. HiTech I agree with you that the max lift coefficient in Wells calculation is to high and the difference was caused by the use of full flaps. In AHT it list lift coefficients without flaps but the coresponding numbers are to high for any of the A/C envolved. Wells pointed this out to me in an earlier post. In fact the number listed for the P-51 is 1.89 which would approximate your findings. I believe that the same is true for the P-38. My question is what lift coefficients are you using for your FM's?

F4UDOA

[wells]

Right Funked, that 1.9 is the Clmax of the entire airframe, but HT is right, it is too high for a clean configuration and without considering the effect of propwash because the pitot tube is usually way out on the wing somewhere.  

Hitech, consider this...

The pilot sees 160 mph on the gauge.  What's the thrust at 160 mph?  What's the propwash velocity over the inner portion of the wing and fuselage at that IAS?  What effect does that have on the overall effective airspeed?  Then, what's the 'real' CLmax?  Example:

Thrust ~ 2600 lbs (75% efficiency, 1490 hp)
Propwash velocity ~ 55 mph over 30% surface area (based on the 2600 lbs thrust)
Effective airspeed ~ (55 * 0.3) + 160 = 176.5 mph
CLmax = 1.54 <--- this is reasonable

Are you really factoring in propwash???

[Zigrat]

I just finished junior year as an undergrad in aerospace engineering, only 1 more year till degree baby    

Yeah that graph you posted looks like it should, with stall around 19 degrees aoa and alpha 0L around -1 degree (little higher than i guessed because the wing is cambered even less than id thought).  

If you guys wanna calculate the cl for the wings of any other ww2 planes i wrote a program that does it in matlab for class so it wouldnt be hard if you have the wing planform to figure out the theoretical performance of the wing, but its only usually accurate up to like 16 degrees aoa, where seperation messes all the invisid calculations up. But then again, its probably just better to look at naca test data though i *do* kinda like finding answers then finding they match real world data  

[1776]

<----timidly raises hand, "2+2=4".

"Hope that helps in the AoA thingie...ah..ah.....I used to own a slide-rule."
<quietly leaves room with head down,thinks to self----man,I hope the P-51 turns better, not worse.>

 

[This message has been edited by 1776 (edited 06-06-2000).]

[Ozark]

ROFL...1776!!

That's why I became a firefighter!! It's EZ...Just put the wet stuff on the red stuff.  

[Jochen]

 

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

Welcome back RAM! We really missed you while you were away about one day after quitting!

 

------------------
jochen Jagdflieger JG 2 'Richthofen' Aces High
jochen Geschwaderkommodore (on leave) Jagdgeschwader 2 'Richthofen'  Warbirds

Thanks for the Fw 190A-5 HTC!

Ladysmith wants you forthwith to come to her relief
Burn your briefs you leave for France tonight
Carefully cut the straps of the booby-traps and set the captives free
But don't shoot 'til you see her big blue eyes

[Vermillion]

I have the airfoil data, CLmax, Cdo, and alot of the other data for most of the american fighters at home. I will try to find it when I go home from work tonight.

I found it in several downloadable documents on the NACA server (pre-NASA agency), so if any of you guys have time you can track it down on there.

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

[Downtown]

Verm, don't tease, put the link up.

I know that in the early NACA Days the P-36, P-37, and P-40 Airframes were heavily tested by NACA.

I WANT THAT DATA!

Regardless, send me any P-40 Stuff you got.

------------------

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

[Vermillion]

Downtown, here is the best I can do till I get home and find out where I put it, and where the electronic version is on the web.

Here is where I found them originally.
 http://techreports.larc.nasa.gov/cgi-bin/NTRS

Nice search engine, with most of the stuff we are interested in, located on one of the two NACA servers.

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

[F4UDOA]

Downtown,

Here is your link  http://naca.larc.nasa.gov/reports/1945/naca-report-829/
If you do a search on lift coefficients you will find it also but it is a bit buried.

Verm,

Do you have any info on the P-38 other that AHT? I'am having a hard time with that one. Also looking for info on undated drag numbers for the F4U. The drag numbers in this document are for early model F4U-1. I know modifications were made to the -1A and D IE bubble canopy, cowl flaps sealed in front of pilot, wings surfaces faired and sealed.
Oh and by the way if you come back to Phila area on June 17 or 18 there will be a F4U at Willow Grove NAS for an Airshow. Let me know.

Later
F4UDOA

[wells]

F4u,

E-mail me, I can probably help you with some of that info...

[Vermillion]

The NACA Report # 829, that F4UDOA posted the link too, is the one I had printed out at home and was thinking of. It has alot of data on the P-51B, P-39 (P-63?), F6F, F4U, Helldiver, Brewster Buffalo, F4F (FM2?), Dauntless, Catalina, and a couple of others.

Also if you use that search engine I posted the link too, and use "Flight Characterisitics" as search keys, you will find ALOT more reports, but most of them you will have too order.

Good Luck!

F4UDOA, On Memorial Day I came up to Lancaster (first time since last time I told you about it) and helped my girlfriend to move down to live with me, so I probably won't be up in that area, unless I come to Philly for work (which happens occaisonally).  If I do, we can arange to meet for dinner and a beer. I would have tried on Memorial day weekend, but there wasn't any spare time, and it was a nightmare moving her 450 miles.

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