Spit vs. Messer : Design vs. Design

[Angus]

Scholzie, I may not have made my point clear enough,or perhaps my definition of zoom may be wrong, if that is the case I am sorry.
I define zoom as energy based climb, that is ((Mass * speed)- drag), while climb directly is a function of lift weight thrust and drag.
Now, if you compare a V2 to a cannonshell, the cannonshell only has the zoom after launch, and no thrust, while the V2 only has thrust and no zoom at all.

One is flying from the initial energy, while the other flies by current energy.

So, when it goes to comparing aircraft which revert from fast level flight (or dive) to a steep climb, the pure climb potency becomes less important than the mass * speed, especially in the beginning.
Then, the thrust+lift vs weight becomes gradually more important.

If you think I am wrong about this, consider that in those cirkumstances a Zeke should be a finer zoomer than say a F4U, and a Spit I should then also outzoom a 109E.......................

[gripen]

Originally posted by Crumpp
As funny as your aeronautical theories!!

Well, if some one is interested about funny aeronautical theories, then just look for the Crumpp's "wet lifting area" or his theory on swept back wings in another  thread ("Explain this and win the prize").

gripen

[GScholz]

Originally posted by Angus
So, when it goes to comparing aircraft which revert from fast level flight (or dive) to a steep climb, the pure climb potency becomes less important than the mass * speed, especially in the beginning.
Then, the thrust+lift vs weight becomes gradually more important.

This is exactly what I described in my previous posts. Plead read them more carefully.

[MANDO]

Originally posted by GScholz
This is exactly what I described in my previous posts. Plead read them more carefully.

Quite the opposite.

In any case, lets compare a 88mm AA gun with a 12.5mm MG, both firing at 70 degrees, the 12'5mm have even better muzzle velocity and the 88mm shell is more draggy, which is going to have better range? Now go a place a very small propeller at the nose of these 12.5 rounds, with a ridiculous power/weight ratio and lets see whether that improves the range or not ...

[Crumpp]

Well, if some one is interested about funny aeronautical theories, then just look for the Crumpp's "wet lifting area" or his theory on swept back wings in another thread ("Explain this and win the prize").

Or Gripen's "check out my wooden model! "  in the same thread!

Crumpp

[Crumpp]

This is exactly what I described in my previous posts. Plead read them more carefully.

And if you look at the power curves of the 801 vs. DB engines in their contemporary planes, the 801 maintains a large power advantage at low altitudes.  As much as 300 or more horsepower depending on the engine/alt considered.  

Crumpp

[GScholz]

Originally posted by GScholz
Also note that the higher the initial speed, the more the weight factor becomes dominant. Likewise, the lower the initial speed the more power to weight factor becomes dominant.

Also note that in a match up between a heavy plane with poor power to weight, and a light plane with good power to weigh: All other factors being equal the heavier plane will always pull away from the lighter plane initially in the zoom. The lighter plane however will catch up in the final stages of the climb. Even if both planes can zoom up to the exact same altitude, the heavier plane will always get halfway first. This is because in the initial stage speed is high and so is drag. That means there is little available excess engine power since most of it is countering drag. Inertia is then the only force available to counter gravity in a zoom climb. However as speed falls off, so does drag, and more excess engine power becomes available to counter gravity. This happens just about when the P-47 starts to flounder while its pilot is chanting "stall! stall! stall!" to the 109/Spit/Lala/Niki that is hanging on its propeller behind him slowly climbing closer and closer.

Originally posted by Angus
So, when it goes to comparing aircraft which revert from fast level flight (or dive) to a steep climb, the pure climb potency becomes less important than the mass * speed, especially in the beginning.
Then, the thrust+lift vs weight becomes gradually more important.

Originally posted by GScholz
This is exactly what I described in my previous posts. Plead read them more carefully.

Originally posted by MANDO
Quite the opposite.

If you are unable to follow a simple argument, please do not bother me with it.

Originally posted by MANDO
In any case, lets compare a 88mm AA gun with a 12.5mm MG, both firing at 70 degrees, the 12'5mm have even better muzzle velocity and the 88mm shell is more draggy, which is going to have better range? Now go a place a very small propeller at the nose of these 12.5 rounds, with a ridiculous power/weight ratio and lets see whether that improves the range or not ...

What part of "all other factors being equal" do you not understand? Obviously if you compare two planes with wildly different performance ALL OTHER FACTORS ARE NOT EQUAL.

I see your cretinous "88 vs. .50 cal" match up, and raise you a "B-17 vs. 109G-10" match up. Obviously the B-17 has an enormous weight advantage, so obviously by your logic the B-17 should out zoom the 109 by far. This is obviously completely and utterly laughable.

Also what do you consider a "ridiculous power/weight ratio"? The P-51D has never been accused of being an over-powered WWII fighter, still its engine thrust is about 15% of the fully laden weight of the aircraft. I would wager that the 109G-10's thrust is more than 20% of its weight.

[GScholz]

Originally posted by Crumpp
And if you look at the power curves of the 801 vs. DB engines in their contemporary planes, the 801 maintains a large power advantage at low altitudes.  As much as 300 or more horsepower depending on the engine/alt considered.  

Crumpp

I have no doubt. I've always been of the belief that the 190 was the superior performer at lower altitudes. The only reason the 109 was better at altitude was because the DB didn't lose as much power as the BMW did with alt. IMHO of course.

[Angus]

This is going in circles.
Goes all the way down to dropping cannonballs down from the leaning tower of Pisa.
Now, Scholzie, you did a wee of oranges-apples comparison by toping Mando's bullet-shell comparison, i.e. the B17 to the 109G10.
Better would be to equal the speed and drag. So imagine 2 G10's at say 350 mph, one being 5 tonnes heavier than the other.
Providing that the structure would make a swift steep curve, say 65 degs, which one would dart upwards higher?
As far as I know, the heavier one. The lighter would start to gain near the stall though.
This would all make interesting 3d curves no doubt. Wonder if there are any?

P.S. I won't belive that the V2 would go to 40.000 feet faster than a 15 inch shell. And NEVER to 20K.
But...do you know how fast they went? All ears really

[GScholz]

The heavier 109 OBVIOUSLY. That is what I have been saying for the better part of this page. Did IQ's suddenly drop sharply or something?

[Crumpp]

I have no doubt. I've always been of the belief that the 190 was the superior performer at lower altitudes. The only reason the 109 was better at altitude was because the DB didn't lose as much power as the BMW did with alt. IMHO of course.

That is correct.  At altitude the DB has a lot more Horsepower.

Crumpp

[Angus]

Hi all
Just popped in to tell you that I am prowling along with that RAF document.
It will basically list all fighter deploys to all RAF fighter units at all fronts (AFAIK)
So, not just the Spits, - hell gotta read it all to hair them out, so I'd better do all.
Many surprizes. Such as mk V's being deployed (although in little quantity) as late as 43/44, while griffon engined XII's had been around for a while!!!!
And XIV's in the far east actually!
One squad went all the way from Gladiators to Tempests in mere 4 years.
Feel free to ask, but warning, I'm only up to 41st sqn, gotta go all the way to 600+

[MiloMorai]

For Barbi.

You should read this report, especially the last paragraph about 100 grade fuel and note the date of 11.39.

http://www.fourthfightergroup.com/eagles/spit1-12lbs.jpg

Lets not hear any more about the lack of 100 grade fuel during BoB.

Then there is this:

The BF 109E flight handbook states:

"Die Höhenruderkräfte und Flossenbelastungen werden bei hoher Fahrt sehr groß."  (The elevator forces and fin loads become very large during high speed)

 L.Dv.556/3, BF 109 E Flugzeughandbuch, (Berlin, December 1939), p. 19

[Angus]

1939!!!!
Well, well.
Shows that the engines certainly would take it.
Now the flight tests on that website put the Spit I in the same ballpark as the 109 while running on 87 octanes.
The 109 outperforms the Spitfire until you equip the Spitfire with a CS airscrew, then the Spitfire has roughly the same speed, but better climb.
(Calculated to NM the Spitfire hauls rougly 10% more than the 109. Now to power, the both have AFAIK roughly the same power, but Izzy claims the 109 has more, that would leave the 109 with a sorry lift though)
So, feel free to promote performance figures with 100 octs, and also MK II's with 100 octs. Those all participated in the BoB.
My feeling is that both fuel types were used, and with both 2 blade and CS-3-blade props in use, as well as MK I and II's, that explains exactly how LW and RAF anecdotes vary in both climing being both faster and slower in regards of climb and speed.
Galland thought (early BoB) the 109 to be some 10 km/h faster,- yet some Spitty pilots report catching 109's after a long chase.
And Hurricanes with 100 octs may explain why some Hurry pilots report outclimbing Spits from other squadrons.....

[Crumpp]

"Die Höhenruderkräfte und Flossenbelastungen werden bei hoher Fahrt sehr groß." (The elevator forces and fin loads become very large during high speed)

I believe Gollob uses the word "unacceptable".

Crumpp