Author Topic: 109F vrs the spit9 (Read 5272 times)

VO101_Isegrim · « **Reply #90 on:** August 27, 2003, 10:37:17 AM »

Interesting selection of aircraft, Mike, however, you numbers seems to mismatch real life test a bit. At least your numbers doesn`t really match the maximum rate of climb in the Kennblatt fur Bf 109F-1/F-2 which states 18.5 m/sec.

So I decided to make a little comparison of climb rates. I only used your data for Spitfires, so that there could be no error. However, I would stick to real life test data for German planes instead of rough estimations done in Britain and the USA.

Enjoy!

mw · « **Reply #91 on:** August 27, 2003, 10:46:35 AM »

hah! That's worth a good chuckle

Good one!

mw · « **Reply #92 on:** August 27, 2003, 10:49:41 AM »

Oh yeah, there's the 109K! I knew that was coming!

With a DB 605L no less

hehe

VO101_Isegrim · « **Reply #93 on:** August 27, 2003, 11:11:34 AM »

Quote

Originally posted by mw
Oh yeah, there's the 109K! I knew that was coming! With a DB 605L no less hehe

What`s the problem? I think it`s entirely fair to compare the 109K to the Spitfire V. Or is the 1700HP DB605L a problem? Boy, I knew I would have to compare with the more usual 2000HP DB 605D engine!

At least, if it`s fair to compare the 109F-2 (introduced in service in October 1940) with the Spitfire IXLF (introduced in service April 1943)...

You can`t say anything, I took all Spitfire data from your site.

niklas · « **Reply #94 on:** August 27, 2003, 12:49:11 PM »

Quote

Originally posted by mw
Comparing 109F and Spit IX climb:

F4 Kennblatt shows 3327 ft/min which is very close to RAE. USAAF shows 3,400 ft/min. Pretty fair agreement between RAE, Kennblatt fur das Flugzeugmuster, and USAAF.

Have at it!

ok, now the fun is over. THIS finally says everthing about you!

It´s really interesting to see how you select always the worst data you can find while neglection good data from the same source
Earlier you said you don´t trust the Kennblatt for the F. Now you select the data out of it. What you of course DON`T mention is that in the same Kennblatt the 109F1/F2 is listed with 20.5m/s, roughly 4100ft/min!!! Why don´t you mention this eh?

Oh btw, +15lb and +18lb is always emergency power for the 61 and 66. 1.3ata@2500rpm is only combat power for the F4, and 2400rpm only for the F1/F2.

Go on in several forums to present such stupid comparisons. Maybe you find people who don´t have the background to judge whether this comparison makes sense or not. Obviously you have fun to convince people in such a poor way.
If it´s your "style" to discuss, hiding informations, neglecting facts and data, picking only what´s serving you - go on, if you need it. It says a lot about you, and it´s not positive.

niklas (over and out)

Angus · « **Reply #95 on:** August 27, 2003, 06:18:48 PM »

NOW NOW Gentlemen!

Niklas and Isengrim: you are accusing MW of forwarding data in exactly the way you frequently do yourselves. Greet yer soulmate instead.
Anyway, there is a list of topics to be dealt with, here we go....
From MW we see data that usually lists the Spitfire as superior, since the data charts are "selected" in such a way that they show the lower performance of the 109 vs carefully trimmed peak performance of the Spit. Well,,,according to the above.
From Niklas, through many a text scruffle through the time, I have the following information, chopped down in 2 main categories, chopped down in further subcategories:

Spit wing is inferior! For Speed, climb and maneuver.

Firstly, the wing design is obsolete and behind the 109 design.

A) The leading edge has been destroyed by armament while the 109 uses its brilliant design to incorprate slats which drastically improve performance in tight situations.
B) The elliptical design leaves the wing with unessecary wing area and an unfavourable aspect ratio. Elliptical shape does not compensate for the loss in Aspect ratio regarding induced drag. and as recently mentioned, wing area aone does not create lift. Wing loading is irrelevant.

Secondly, Spits engine and frontal area was lagging behind!

A) DB as a smaller frontal area and the 109 has a more aerodynamical nose
B)The DB output pro weight, altitude, boost, duration, injection or whatever was always on the better side of the RR Merlin
C)Furthermore, the 109's layout allowed a more effective propeller than the Spit, and furthermore, the Propeller development/manufacture for the DB/109 lay ahead.

I guess, that all data even hinting that the poor soddy Spit performs anywhere near the divine 109, must be manipulated in one way or another, - that is if there is truth in all of the Niklas Data, - save it may have been tweaked in the way he is now accusing MW for.

There we come to comparing different things really, thereby approaching Isengrims point.
So, Isengrim:
According to my Data, the 109F1/2 were starting deployment in April 1941. The Spitfire Mk IX started service in July 1942. A year between where the British had been the underdogs regarding speed and climb (although they spiced up and chopped some squadrons (!) of the Mk V). After that, Spit IX vs 109F as duelists of the skies, running paralell with the 109G2/G6 who's dogfighting skills were the lesser. Comparing the 109F with all sorts of the Spit IX is therefor quite normal, - those met and fought, - if not the 109F, then the G2 and G6, - does not make such a vast difference. However, the 109K and a SpitV, - they have about 2 years between them, - 109K deliveries beginning in October 1944.
There were many occations of the Spit IX fighting the 109F, however I doubt the 109K ever met the Spit V...
So, pulling this up, - what is wrong with MW's data? his data is not wrong, just the presentation, and I think you two guys just topped that, not just now, but many times!

GScholz · « **Reply #96 on:** August 27, 2003, 06:43:58 PM »

The first Bf 109F1 fighters were delivered to operational units in January 1941.

niklas · « **Reply #97 on:** August 28, 2003, 01:47:16 AM »

Quote

Originally posted by Angus

Niklas and Isengrim: you are accusing MW of forwarding data in exactly the way you frequently do yourselves. Greet yer soulmate instead.

Your reply forces me to answer once more. Please give me few examples for this accusation!!!!

Everyone can write mistakes, this is no problem. Telling only half the truth and presenting only selected data is the problem, especially when knowing more and better data.
It was me who showed the Naca rollrate comparison chart first here, it was me who gave the hint for the 868 report, it was me who informed about the SpitVA report. It was me who gave you and all otheres best informations based on scientific sources from all sides about this topic.
And what come from Spit-supporting side? Just sentences like "What i heard Spits were always superior to the 109". Very scientific and well proven data....

Quote

Spit wing is inferior! For Speed, climb and maneuver.

Correct, and everything i said can be proven in a scientific manner. You forgot about the oudated 4-digit airfoil producing high pitching moments btw. Every mid-war aircraft later used the advanced 5-digit airfoil, while the 109 used right from the beginning the 2R1 with reflexed shape.

Quote

B) The elliptical design leaves the wing with unessecary wing area and an unfavourable aspect ratio.

Clipped wing showed that supermarine themselves knew that area was wasted. The shape became not favourable on the other side, except for rolling. It would be interesting to know whether there were projects with completly new wing shape and lower wing area.

Quote

Elliptical shape does not compensate for the loss in Aspect ratio regarding induced drag. and as recently mentioned, wing area aone does not create lift. Wing loading is irrelevant.

First sentence correct. A flat plate won´t produce much lift, even if you have a wingarea of 10000ft^2. I did NOT say it´s irrelevant, i just said it´s not an adequate comparison factor, because wing designs were too different.

Quote

Secondly, Spits engine and frontal area was lagging behind!

Correct. Todays high speed fighter resemble much more the dart nose of the 109. Every child could see this.

Quote

B)The DB output pro weight, altitude, boost, duration, injection or whatever was always on the better side of the RR Merlin

Where did i say this? Please give me the quote! If you don´t find the quote i want an excuse for this, it´s bad style to quote me wrong.

Quote

C)Furthermore, the 109's layout allowed a more effective propeller than the Spit, and furthermore, the Propeller development/manufacture for the DB/109 lay ahead.

Correct. Schwarz investigated Rotol airsrews, the thickness ratios especially in the roots was not good (too thick).

Quote

I guess, that all data even hinting that the poor soddy Spit performs anywhere near the divine 109, must be manipulated in one way or another

The spit usually had more power and was performing roughly equal or worse. So from an aerodynamic viewpoint it must have been inferior.

But aside from my technical points here, please give me the quotes i demanded where you accuse me of statements i haven´t made as far as i can remember. Let´s see if you can bring them or if it´s just another example of uncorrect data presentation (to forumlate it the harmless way)

niklas

Angus · « **Reply #98 on:** August 28, 2003, 06:12:32 AM »

Better reply again:D
First thing I stumbled on was the clipped wing sentence.
As far as my sources state, the wing got clipped to improve rollrate and raise top speed, however, it would reduce climb and worsen stall characteristics. Many pilots did not like the clipped versions because of this.
Now about some here displaying selected data, I found this:
(Gripen giving some points to you)
"Niklas,
There is not much sense to compare weights of the Merlin 6X and DB605A or should we compare outputs at 10000m? Generally single stage Merlins were lighter than single stage DB605s but single stage DBs did a bit better at high altitude than single stage Merlins. It should be also noted that the high altitude DB605AS did not reach production before spring 1944 while the two stage Merlins had been around about two years by that time. Two stage DBs failed to reach more than experimental service during war. RR was able to develop engines to service stage faster than DB.

gripen"
Who was comparing apples and oranges?
Now a lot about this:
"B)The DB output pro weight, altitude, boost, duration, injection or whatever was always on the better side of the RR Merlin "
Is to be found in the same thread as Gripen entered. A good source of information there, where you basically strive to prove the above!
Then these are new news to me, that the Spitfire made a little compensation to its bad wing with more power, - bear in mind also that the 109 usually has a more favourable power loading through all years of the war. (Exceptions were of course the tuned up Spittys)
Oh, instead of an excuse, I hope this is sufficient. The name of the thread is: RR Merlin vs the DB series, under some dust in the AH BB.
And then to this:
" A flat plate won´t produce much lift, even if you have a wingarea of 10000ft^2"
Did you ever try to hold a metal sheet in a storm? Given some power and an A of A, any flat sheet will produce lift. Of course it is a valid comparison factor, even between different wing designs. It's like saying: "Wing loading does not matter"

These words said, I will withdraw from the keyboard, take off in the skies of AH to blast some more undermodelled 109's with my poor soddy stupid-winged-overmodelled Spit IX.

niklas · « **Reply #99 on:** August 28, 2003, 06:27:26 AM »

Please, you quote an answer from gripen to proove what i should have said? Are you crazy?

This is what you said here on the open forum with the meaning that i have said something similar:
"The DB output pro weight, altitude, boost, duration, injection or whatever was always on the better side of the RR Merlin "

Now please find a quote from me saying this really! Do it, find it, or take the quote back and excuse yourself for incorrectly quoting me!

Actually this is what i wrote:
"If you reduce the question down to a power comparison, neglecting material, fuel, design, installation and other things, RR engines WILL LEAD, especially in a power/volume comparison"

Really, i´d like to read an excuse from you here soon...

niklas

Angus · « **Reply #100 on:** August 28, 2003, 07:08:03 AM »

You'll have to read the whole thread through to sum it up really, it was a quick snatch.
Was your sentence there?

Angus · « **Reply #101 on:** August 28, 2003, 07:23:30 AM »

Ahh,,,found it.
OK OK OK,,,so the Merlin was more powerful, even at the same RPM!
The rest holds, especially the wing thingie.
Still unexplained why the Spitfire could fly as fast pro Hp/alt with more weight, and pull more Newtons to altitude pro hp. I mean with inferior and out-dated wing structure, how can that happen........

niklas · « **Reply #102 on:** August 28, 2003, 12:01:38 PM »

For an engine comparison it´s probably better to compare the air mass flow rather than a single value like rpm, volume, or boost. Booth 3 values are connected together and can be expressed by a single one, mass flow.
Also the well known octan value is not very exact for all situations but that´s a different story. It was replaced in germany during wartime with a kind of "air overloaded factor curve".

This is the data for the 601E of the F4 with full boost:
2700rpm, 1,42ata, 33,9 liter , 1350PS

The Merlin 45 (correct my data if wrong, not 100% sure, power for sealevel!):
3000rpm, 2,088ata (+16), 27liter, ~1450PS

The Merlin 61
3000rpm, 2,02ata(+15), 27liter, 1510PS

If we put the first 3 factors together as a proportional factor to mass flow, and build the ratio PS/Massflow(factor) then we get:
0.0104 for the 601E and
0.0087 for the Merlin 45 and
0.0091 for Merlin 61

So it looks like the 601E is superior, more power per massflow.

But we (oh sry, I do) want to do it even more scientific. If you compress air, it get´s hot. This reduces density, thus massflow.

Massflow = N * V * D

N = N_mot / (2*60) (2 because we pull only every 2nd stroke air, 60 to convert from rpm to rev. per second)
V = engine volume in liter / 1000 (for m^3)
D = density = [ (p/p0)^(1/k) ] * D0 (p manifold pressure, p0, D0 atmospheric pressure and density at sealevel, k = 1.235 for air)

N / V / D / Massflow(kg/s):
22.5 / 33.9 / 1.627 / 1.241 for the 601E and
25 / 27 / 2.223 / 1.500 for the Merlin 45 and
25 / 27 / 2.165 / 1.461 for Merlin 61

Power / Massflow is:
1087 for 601E and
966 for the Merlin 45 and
1033 for Merlin 61

601 is still leading, and in case Merlin engines use intercooler or charger cooler, the comparison will be even more in favour of the 601, because cooler air means higher massflow.

I hope you were able to follow so far...

It shouldn´t surprise someone that the slow running engine has a more efficient combustion. The engines with the highest efficiency today are Diesel engines for ships whith piston bores of 3 feet and strokes of over 6feet. They run so slow, around 50-100rpm, that they don´t need a gear (no losses), the propeller is directly attached to the shaft.

At speeds near or over 500km/h, weight differences in reasonable limits have only a minor influence on top speed for both fighters.

Was the Spit as fast or climbed as good with SAME power? Really? Better check your numbers hihi

niklas

humble · « **Reply #103 on:** August 28, 2003, 12:49:05 PM »

Assuming a co-e initial merge I'd say the outcome will largely depend on pilot skill. The spit IX has a clear edge in performance in a knife fight...but the 109 is probably equal in an E fight. Assuming the 109 doesn't have gondola's (if so then edge in all to spitty) I'd guess the range hitting power and ammo load in 20mm all favor the spitty. Since the 109F is normally flown by "experten" and the population of spit dweebs...er drivers...is much less skilled (obviously there are more than a few outstanding sticks flying spitties) I'd say the vegas line is 109F 3 to 2.

Angus · « **Reply #104 on:** August 28, 2003, 06:35:29 PM »

I was able to follow as far as towards a general assumption.... DB is superior, - and thereby I do not yet owe you an apologize for referring to you stating that. Anyway, you promoted the data, so as far as your evidence goes, the Spit now hardly has anything in its favour:(
Nice to see a smilie from you as well, Niklas
Now, for the rest.....running to max speed:)
Spit I (merlin III) 1030 hp, weight 5844 lb typical,
6200 lb max, topping speed at 19K 365 mph, cruising 304 mph at 15K.
109E4 1175 hp, weight 4685-5875 lbs max,top speed 348 mph at 14650 ft, cruise 300 mph at 13125 feet
So, the SpitI is heavier and faster!
Climb:
There it gets a tad more complicated. More hairy numbers and so on, and the need to calculate things to Newtons. I have some data on the spits, but need more on the 109's. I presume, Niklas that you will enter some. Anyway, some examples:
A spit I would be at 15K in 3 and a half minutes, 15K in 5 minutes 18 secs, 20 K at 7:42.
A Spit IX would be at 10K at 2,7 mins, 20K at 5.6 etc etc.
anyway, I'll try to get this to an excel chart, but I sorely need more 109 data. Climb and weight figures?