Spitfire Mk.XIV vs P-51D Mustang

[Soren]

Bill,

What part about this is nonesense??:

"Lift coefficient may be used to relate the total lift generated by an aircraft to the total area of the wing of the aircraft."

Weight / Wing area = Wing loading:
4000 kg / 22 m^2 = 181.18 kg/m^2
Weight / Wing area / CL = lift-loading:
4000 kg / 22 m^2 / 1.6 = 113.63 kg/m^2

A lower Cl equals a higher lift-loading and vice versa, everything else being equal.

Example:
4000 kg / 22 m^2 / 1.3 = 139 kg/m^2
4000 kg / 22 m^2 / 1.5 = 121 kg/m^2

So how exactly do you figure that to be the lower the Cl the more efficient the a/c is ? What are you talking about Bill ? It is you who isn't making any sense.

The lift coefficient (Cl) is an efficiency indicator of lift production as it tells us how efficient a wing is at producing lift pr. surface area. As we both know different airfoil & wing designs produce different amounts of lift & drag, thus the need for the Cl.

That having been said we know the Clmax of both the Fw-190's & P-51's wing, 1.58 & 1.35 respectively, both figures established in extensive windtunnel tests. The Fw-190's high Clmax stems mainly from its choice of airfoil, the high lift NACA 23000 series.

It is the lower lift-loading of the Fw-190 which allowed it to turn better than the P-51, the Fw-190's wing generating more lift pr. wing surface area:

4,575 kg / 21.64 m^2 / 1.35 = 156.6 kg/m^2
4,270 kg / 18.30 m^2 / 1.58 = 147.6 kg/m^2

[kool kitty89]

Originally Posted by Kurfürst

The following is from a British paper titled 'PROGRAMME FOR RE-EQUIPMENT OF DAY FIGHTER-TYPE SQUADRONS'

Force as at 1 Jan 1944:

Spitfire V - 24 Sqns.
Spitfire VII - 2 Sqns.
Spitfire IXF - 11 Sqns.
Spitfire IXHF - 0 Sqns.
Spitfire IXLF - 9 Sqns.
Spitfire XII - 2 Sqns.
Spitfire XIV - 0 Sqns.
Typhoon - 19 Sqns.
Whirlwind - 1 Sqn.
Spitfire XI - 1 Sqn.
Mosquito IX - 1 Sqn.
Totals: 86 Sqns.

I thought the Whirlwind was retired in 1943.

[drgondog]

Originally Posted by Kurfürst

PS: The /AS version 109s were produced from December 1943 (but only two of them, probably the protos, so production is really from January), they were being sent to the Gruppen since April 1944, at least March/April is the first month I know they are mentioned.
But basically you are right in that Mustangs commonly encountered G-6s well until the 2nd half of 1944. OTOH I believe G-6s would encounter P-47s and P-38s more commonly than Mustangs.

The encounters with P-38s would be in the same areas as Mustangs as both were used exclusively for target escort, relegating the P-47s (and Spitfires) to Penetration and Withdrawal duties due to lack of range. So, basically all the units east of Frankfurt would be dealing primarily with Mustangs and P-38s.

[drgondog]

Originally Posted by Soren

Bill,

What part about this is nonesense??:

"Lift coefficient may be used to relate the total lift generated by an aircraft to the total area of the wing of the aircraft."

True - this is not nonsense

Weight / Wing area = Wing loading:
4000 kg / 22 m^2 = 181.18 kg/m^2
Weight / Wing area / CL = lift-loading:
4000 kg / 22 m^2 / 1.6 = 113.63 kg/m^2

Weight/Wing Area = Wt/A = Lift/Wing Area = L/A

Lift = L = Cl*q*Wing Aea = L

(L/Wing Area)/Cl = q= 1/2*rho*V>>2

in what manner of analysis would you offer dynamic pressure as an 'efficiency'?

The lift coefficient (Cl) is an efficiency indicator of lift production as it tells us how efficient a wing is at producing lift pr. surface area. As we both know different airfoil & wing designs produce different amounts of lift & drag, thus the need for the Cl.

Interesting, true and irrelevant to your thesis

That having been said we know the Clmax of both the Fw-190's & P-51's wing, 1.58 & 1.35 respectively, both figures established in extensive windtunnel tests. The Fw-190's high Clmax stems mainly from its choice of airfoil, the high lift NACA 23000 series.

It is the lower lift-loading of the Fw-190 which allowed it to turn better than the P-51, the Fw-190's wing generating more lift pr. wing surface area:

Interesting but unproven and your 'analysis' doesn't prove it

Seriously, where did you discover 'Lift Loading' as a concept - I actually would like to see the analysis??

[Timppa]

Originally Posted by Kurfürst

...As of the 'G-6s in 1945' Mike 'Bullshit' Williams topos..

Is it possible to keep the discussion civil ?
This is the absolutely the best and most knowledgeable forum on WW2 aircraft that I have seen yet. Let's keep it that way.

[DerAdlerIstGelandet]

I will say this for the last time! I have said this many times in other threads. So have other moderators. Everyone seems to enjoy ignoring it. No more!

If I read another bullshit remark about Mike Williams, the person who said it will no longer post in this forum.

Mike Williams is not here to defend himself. Talking about someone like that is cowardly in my opinion. Let alone childish!

If you disagree with Mike Williams, that is fine. You can discuss it here, but you can do so in a civil manner.

Is that clear to everyone?

[drgondog]

soren - let's not de rail this on aero. Take it to performance thread

[Soren]

Interesting but unproven and your 'analysis' doesn't prove it

Bill how does my analysis not prove it ???

To do an accurate comparison you HAVE to know the Clmax and you HAVE to divide the wing-loading with it. Why ? Because it's a coefficient, it's meant to tell you how efficient the wing is at providing lift pr. surface area.

So if the wing of aircraft A has a lift coefficient which is 30% higher than that of aircraft B, then aircraft B's wing provides 30% more lift for every square cm, m, foot etc etc than the wing of aircraft A. The very purpose of Cl as an efficiency indicator.

Originally Posted by drgondog

Seriously, where did you discover 'Lift Loading' as a concept - I actually would like to see the analysis??

Bill it is so very commonly referred to by a lot of people, also NASA. Try asking Gene as-well, I doubt he will have any objections with the term.

Try typing lift-loading + wing-loading on google.

[Soren]

Originally Posted by drgondog

soren - let's not de rail this on aero. Take it to performance thread

Not sure we're derailing anything here, but where's the performance thread ?

[drgondog]

Originally Posted by Soren

Bill how does my analysis not prove it ???

To do an accurate comparison you HAVE to know the Clmax and you HAVE to divide the wing-loading with it. Why ? Because it's a coefficient, it's meant to tell you how efficient the wing is at providing lift pr. surface area.

Soren - I googled Lif Loading and Lift-loading and got nothing. I haven't been active in Aero research papers but have never heard of 'lift loading in context of efficiency"

Having said that when you do the math WL/CL = q

So if the wing if aircraft A has a lift coefficient which is 30% higher than that of aircraft B, then aircraft B's wing provides 30% more lift for every square cm, m, foot etc etc than the wing of aircraft A. The very purpose of Cl as an efficiency indicator.

CL is simply a non dimensional coefficient, obtainable from two dimensional wing sections and later tweaked via wind tunnel testing to validate the three dimensional effects. As you know the slopes are essentially constant (but different from each other) with different stalling 'breaks' at max CL to AoA and different intersect points at zero AoA and zero CL.

For three dimensional wings the slope of the CL to AoA increases with AR and also, to a smaller degree with tip chord ratios.. etc, etc.

Having said this CL = Lift (or weight in steady flight)/(q*Awing) where q = 1/2*rho* V>>2 (the dynamic freestream pressure)

Bill it is so very commonly referred to by a lot of people, also NASA.

Try typing lift-loading + wing-loading on google.

Didn't find it, haven't heard it, math says WL/CL = q so it ain't non dimensional, it's a force divided by an area..

If two different ships are at same velocity and altitude we could say WL1/CL1 is proportional to WL2/CL2.. so extend your thesis from there? Clearly if WL1 > WL2, then CL1 has to be greater than CL2 for this equality to exist... but I can't see what you can say about comparing an Fw 190 to a P-51 based on WL1/CL1=q

[Soren]

Yes a coefficient is a dimensionless figure Bill (Any nr alone is), that is until you add a dimension to it, which is what I did when I used meters as a reference point. The Cl is just a coefficient, meant to either multiply or divide other known dimensional figures with.

And since we know the true Clmax of the Fw-190's & P-51's wing, established in fullscale windtunnel tests, we can also tell the difference between the two in terms of which a/c provides the most lift pr. unit of its own weight.

[DerAdlerIstGelandet]

I will be honest. I am a merely a technician, but I too have never heard of Lift Loading in aerodymics. I have read it on data plates on our John Deer Tractors that we used to tow the aircraft with.

I just googled it too, to see if I am stupid and I found nothing either.

[Soren]

Well here's one from google:
http://en.scientificcommons.org/18471522

[Soren]

Type "Lift-loading Wing-loading" like so on google and look.

Then try "lift-loading stalling".

[DerAdlerIstGelandet]

Wing loading I have heard of, but not lift loading.

I think you are talking about wing loading. Everytime I did a search (even with your search criteria) the only things that came up were "wing loading".

But then again I am merely a technician...