Messerschmitt 109 - myths and facts - article now out

[joeblogs]

There are some nice discussions of the types and when they were developed at

http://www.turbochargedpower.com/History.htm

http://www.lextreme.com/turbo.html

The main difference is that a Roots type supercharger does not actually compress the air in the blower, that's done in the manifold. In a centrifugal supercharger, the compression happens in the blower itself. The former tends to heat the air more than the latter, but the latter is not as good for engines operated with frequent changes in RPM (e.g. cars).

-blogs

Originally posted by straffo
You will need to explain because I don't  now how to translate "root" in this context

[straffo]

Well sorry I can't help

A engine for me is a thing that start when I turn a key or I press a button

I'm completly incompetent in this area

[Charge]

edit: Sorry, didn't read enough before replying. Ignore.

Roots compressor has two profiled vanes rotating very close to each other.

Mechanical compressor of a WW2 a/c and turbosupercharged ones have nearly similar intake blower which sucks the air in from the center and uses centrifugal force to compress the air before it enters the intake manifold. The difference is where the force to drive the intake blower is taken. In mechanical it is taken from camshaft and in turbo it is taken from a turbine rotated by exhaust pressure.

These older types which are used e.g. in Merlin engines are manufactured for automobiles too by Rotrex and several other manufacturers.

The speciality of DB is the hydraulic clutch which lets the supercharger and camshaft to rotate at different speeds giving optimal boost from sea level to altitude. Of course in some altitude the intake turbine starts to lose effectiveness rapidly as is evident in many a/c speed charts.

-C+

edit:

From Lextreme: "Then came World War II in 1939, and the Allied forces had an ace up their sleeve in the form of the supercharged Spitfire fighter planes and B-29 SuperFortress bomber. These supercharged planes seemed almost unaffected by the altitude to the delight of Allied pilots and soldiers."

[o0Stream140o]

This is a quote from Arthur Feidler, a 325th Ace that flew the P-51 (Mayfair #35). This is a quote from an email I got from him. The question was P-51 vs. 109 and 190

I am sure that some of the opposition would have some question as to my answers but in general I believe all but the best German aces would agree with my answers.
In short we did everything better than the Me-109 or the FW-190. Toward the end of the war, they introduced newer models with larger engines and sometimes the answer is not that clear. The TA-152 (Varient of FW-190) could fly higher and faster than the P-51 at most higher altitudes but they got very few into the war.
But for the average Me-109 and FW 190 that we encountered, we were faster at all altitudes, we climbed better (some claim this is not true), and we flew far higher than the FW-190 and about to the same height as a Me-109 (41,??? feet). The long nosed FW-190 is a question mark as several P-51 pilots stated it ran away from them at various altitudes. I do not know BUT when 4 of us bounced 40 of them at 30,000 feet, we did everything better than they did. Outturned, outsped and outclimbed them. We destroyed 4 of them and they got none of us. I even have the names of the ones we killed. The Czechs found the aircraft (3 FW 190Ds and 1 FW 190A-8)with the pilots still in them. Eventually I found myself alone with them (25 or so) and after several minutes, it started getting too hot for me and I broke for home. Some 190Ds (12 - 15??) chased me to the Alps but could not catch me.
Initially when we got the P-51, they would stay and fight with us but then it got to the point that when we bounced them, even if they outnumbered us, they would normally break for the deck and we had to chase, catch, and destroy them.
If Hitler had allowed the Me-262 to be used from the beginning as a fighter rather than a fighter-bomber, the situation could have become much more complicated.
As I have said before, the quality of the pilot had a great deal to do with the outcome of the encounter. I recall one Luftwaffe pilot who admitted the Spitfire could outturn the 109 but then added that no Spit ever outturned him. It would seem to me that the area where the 109 was better, was in its ability to fly at a lower airspeed than we could and climb very well. With the 190, it took a lot of punishment, had a high rate of roll, and could climb at a very steep attitude which if we followed brought us down too far below our best climb speed. Four of our guys reported such an incident in which the FW-190s were able to stay ahead of our birds and each time we would raise our nose to take a shot at them, our bird would stall. An interesting tactic.

[HoHun]

Hi Stream,

>But for the average Me-109 and FW 190 that we encountered, we were faster at all altitudes, we climbed better (some claim this is not true)

Well, a Mustang wouldn't outclimb a Me 109 at full power, but I believe he's actually saying "no Me 109 ever outclimbed me" in the sense of the Me 109 vs. Spitfire comparison he quotes. As he also mentions that the Luftwaffe fighters were very cautious, I'd say they probably felt that flying near the escorts at best climb speed was not cautious enough :-)

>The long nosed FW-190 is a question mark as several P-51 pilots stated it ran away from them at various altitudes. I do not know BUT when 4 of us bounced 40 of them at 30,000 feet, we did everything better than they did. Outturned, outsped and outclimbed them.

That's exactly what one should expect - the D-9 was only good at up to 20000 ft, the P-51 was markedly superior at 30000 ft.

Interesting that an Allied pilot shares the opinion that the D-9 should be expected to be a good high-altitude fighter - I had thought that was a Luftwaffe misconception resulting from its use as high cover for the even less high-altitude capable Fw 190 :-)

Regards,

Henning (HoHun)

[o0Stream140o]

Henning... I have something to show you... if you can, email me
ColonelStream14(at)virtualcheckertails.com