Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: SageFIN on October 18, 2000, 11:35:00 AM
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The climb and and speed curves on all the 109's except the 109F show two clear points where the otherwise linear curves "bend" or so.
Well, some information I have sought up states that the DB605 engines had a variable speed compressor that adapted to the altitude. Thus the engines power output varied smoothly between the altitudes. So I gather that the climb and speed curves should also be more smooth than they currently are?
A good website that has this information can be found at http://w1.1861.telia.com/~u186104874/db605.htm. (http://w1.1861.telia.com/~u186104874/db605.htm.)
A quote from that page:
"While the conventionel mechanical superchargers consisted of one or two compressors driven via a two-speed gear, Daimler-Benz utilised an ingenious barometricly controlled hydraulic clutch which adjusted the compressor speed and thus the charging of the engine according to the needs at a given altitude.
The conventional method results in a relative loss in efficiency below rated altitude, because the compressor uses energy to produce surplus charging. A graphic presentation of engine output relative to altitude would show a "saw-touth" line: the output in low gear rising with altitude until reaching the rated altitude, then output falls until the high gear kicks in, when the output again rises the rated altitude is reached.
In comparison the Daimler-Benz system is more flexible. A graphic presentation would show a smooth shallow curve. A source of efficiency loss with this system being progressive heating of the oil as pressure in the clutch builds with altitude."
Any comments? I don't know exactly if implementing this system would benefit or hinder the DB605 equipped planes. I would like to see this done anyway (if this whole issue is correct).
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SageFIN
"The wolves are gathering, the stars are shifting...
come, join us in the hunt!"
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I have a comment...
German engines own.
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It would make bugger-all difference to the planes performance in the game, just that the climb/speed charts would look pretty...
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Bah the B-17, P-38, and P-47 all work the same way.
Willy just figured a way to trick a super charger into thinking it was a turbo charger.
- Jig
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Messershimitt designed DB engines? hmm
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Well the climb curve for P-47D sure is smooth and curvy. Why not so for the other planes then? And I do think that if the graphical representation of a planes power output is more rounded than jagged, it would result in a small but perhaps decisive (in some situations) advantage in speed or climb.
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SageFIN
"The wolves are gathering, the stars are shifting...
come, join us in the hunt!"
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Must be another part of the conspiracy...
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Umm. So I came off sounding like an advocate for the universal allied conspiracy theory? I said "other planes" not "axis planes".
I merely wish that if this is an aspect that has not yet been modelled that it would be so. Jigster mentioned that at least the P-38 and B-17 worked the same way. HTC doesn't yet have a curve up for the B-17 but the P-38 and P-47 climb and speed look rather similar.
Sooo... if the DB605 worked in the same way then how come the speed and climb curves for the 109's are quite jagged? And what about Rolls-Royce Merlin? Did it have the same system? I have absolutely no idea. If it had, then shouldn't those curves be more rounded too.
I'm sort of stumbling in the dark here and would appreciate some light. Not from a flamethrower though.
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SageFIN
"The wolves are gathering, the stars are shifting...
come, join us in the hunt!"
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SageFIN,
You came off sounding like part of the universal non-German plane conspiracy theorists.
The non-Allied plane conspiracy was a sham that was revealed when the Japanese turned out to have a good kite. The pro-German guys had been using the Japanese and Italians as armor to defend from alligations that they only cared about German aircraft. As soon as another Axis plane, the N1K2, was shown to be VERY good, they attacked it too (others did as well).
(http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
HTC hasn't shown much inclination to redo those diagrams. If the Bf109 doesn't perform correctly in the game, that is something that should be posted, with evidence.
Sisu
-Karnak
[This message has been edited by Karnak (edited 10-19-2000).]
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Sage, AFAIK the curves on the charts are based off of real performance data. So regardless of what the supercharger was control was supposed to do, this is what the plane did. Some of the shapes do seem a little odd though. I will look into this.
Obviously above the rated altitude, boost and power will drop regardless of what the supercharger speed controller does. Maybe the some of the fluctuations at lower altitudes are due to changes in the efficiency of the fluid coupling with respect to altitude?
The P-47 and P-38 curves are smooth because they had turbosuperchargers which could maintain full rated power to 30,000 feet and beyond.
Nath, German engines had some neat gadgets, but in terms of power output per cubic inch and pound of weight, and especially in high-altitude performance, they weren't quite up to par with US and UK designs. They are still really nice works of engineering art though. BMW and especially DB engines had some really clever design features.
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Hmm... Jumo 213EB, funked? DB 605L? :P
Late war German engines were the best in the world.
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I think that's just so the pilot can set his manifold pressure and not have to worry about pushing the throttle up to maintain it as he gained altitude. The P-51 had the same kinda thing. It wouldn't affect the speed chart any. Any jagged edges are caused by having at least 2 stages in the supercharger. One had to let the manifold pressure drop before the second stage kicked in or else the engine would overboost. There's also ram air effect. Full boost was rarely used on takeoff as the boost would increase with speed. The ram effect raises the critical height about 3000 ft in most cases and from 18k-21k in the DB605.
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Originally posted by Nath-BDP:
Hmm... Jumo 213EB, funked? DB 605L? :P
Late war German engines were the best in the world.
So...why was the Merlin mated with the 109 after the war? (http://bbs.hitechcreations.com/smf/Smileys/default/tongue.gif)
Scary to think of the equipment the Germans could of kept going if they would of designed it simpler. When it takes a team of engineers to build, and another team to try and repair it something ain't right.
Other then the claustraphobia, the US volunteers liked the late model 109's...heck they even got some kills vs the Royal Egyption Spitfires. How ironic is that?
Benz sure had one thing right...fuel injection. If it wasn't for that, the generation of diesel engines might of never come along. Wonder who the Catapillar guy was who stole it and licensed it in the US? (http://bbs.hitechcreations.com/smf/Smileys/default/tongue.gif)
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Nath if you count jets I agree.
But BMW 801 vs Pratt & Whitney R-2800? No contest. The 801 never broke 2000 hp in a production plane while the 2800 was good for... 2800 hp in three different aircraft.
The Jumo and late 213 and late DB 605 were good, but still barely had more power than the Packard-Merlin V-1650-9 in the P-51H, despite having much more displacement and being a bit heavier engine.
Like I said, per cubic inch and per pound of weight, the German engines were nothing special.
[This message has been edited by funked (edited 10-19-2000).]
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Agree on the injection Jig. Last year I did a bunch of reading on the injection system in the BMW 801, found a bunch of pictures from a guy who was restoring one. Then I was looking at mid-60's F-1 Ferrari engine, and... same dang system! (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
[This message has been edited by funked (edited 10-19-2000).]
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I found this great quote:
"Right out of the starting gate, the XP-47M the horse to beat in terms of speed. The XP-47M proved to be nearly as fast as the XP-47J. 488 mph was obtained on at least one flight. The official maximum speed is 470 mph. However, over-boosting the engine could tweak another 15 to 20 mph out of the big fighter. Some may find this next tidbit hard to swallow, however, the test documents still exist.
During durability testing of the C series R-2800 by Republic, it was decided to find out at what manifold pressure and carburetor temperature caused detonation. The technicians at Republic ran the engine at extreme boost pressures that produced 3,600 hp! But wait, it gets even more amazing. They ran it at 3,600 hp for 250 hours, without any failure! This was with common 100 octane avgas. No special fuels were used. Granted, the engines were largely used up, but survived without a single component failure. Try this with Rolls Royce Merlin or Allison V-1710 and see what happens."
Indeed. Try that with some rinky-dink Daimler... (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
Found that here:
http://www.cradleofaviation.org/jordanpart1/0401Seversky-Republicb.html (http://www.cradleofaviation.org/jordanpart1/0401Seversky-Republicb.html)
A FANTASTIC read. Going to buy new ink cartridge for printer now. I'm gonna bind this article for future reference. Wow.
I can't wait to see the 47M or N in AH. The N was a hell of a great plane.
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Lephturn - Chief Trainer
A member of The Flying Pigs http://www.flyingpigs.com (http://www.flyingpigs.com)
(http://tuweb.ucis.dal.ca/~dconrad/ahf/lepht.gif)
"My P-47 is a pretty good ship, she took a round coming 'cross the Channel last trip.
Just thinking 'bout my baby and lettin' her rip, always got me through so far."
- Steve Earl
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P51H never saw combat in the ETO Funked...
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Nice to see the misinformation flowing freely.
Hydraulic clutch oil should heat up more at low altitude due to slippage.
Gasoline injection systems have little to do with Diesel injection (which incidentally, has been around a heck of alot longer)
Funked: Give the Germans 130 octane for the BMW/DB engine, Raise CR, boost, change the timing a bit. Then compare apples to apples.
I will grant you they were behind in exhaust driven supercharger technology tho,
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Nath, there were more P-51H's flying by the end of the war than Ta 152's... P-51H was in full production and in squadron service. We're talking about technology here not combat.
Chisel I'm not saying DB's and Jumos and BMW's were crap. But they were a little bit behind. Having their shops bombed repeatedly hurt production but people don't realize that it slowed development too. And you are right that the Germans didn't have much luck with turbos, the edge for the Allies was more clear-cut there.
[This message has been edited by funked (edited 10-19-2000).]
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Didnt think you were Funked. I know your a FW potato even if your playing a Spitdweeb now. (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
There was also design limits because of the airframes. No intercooled 109s nor turboed FW's.
Did they ever build a 190C prototype? Seen drawings never any info tho.
BTW since I have your attention do you have the idle speed for the BMW801
E-mail me killjoy@telusplanet.net or point me to a site with the info. Thanks
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Are you guys actually asking for a P-51H?
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For the BMW 801D (as installed on USAAF Fw 190G-3), 1200 rpm was the idle speed on the ground. 1400-1500 rpm was used for warm up, and speeds between 600-1000 rpm were supposed to be avoided because of roughness. Once warm up and checks were complete, rpm was set back to 1200 rpm.
Yep they built at least one Fw 190C prototype, which became the Ta 152C. On the Fw 190C prototype they actually had to route the exhaust and compressed intake air outside the fuselage between the engine and the turbo. It looked like Frankenstein, but I guess the failures of the Hirth turbos were the main problem.
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FYI, just a little info on the -51H:
Produced: 555
Normal T/O weight: 9500lb's
Engine: Packard (Merlin) V-1650-9
Normal T/O HP: 1380hp
WEP HP: 2270hp
Max Speed (25,000ft): 487 (50mph faster than the -51D)
Climb to 20,000ft: 6.8 minutes
Range w/ Drop Tanks: 1530 (300 miles less than the -51D)
From MustangsMustangs.com (http://www.p51.mustangsmustangs.com/p51specs.shtml)
From Joe Baugher's Website:
The P-51H was too late to see action in the war in Europe. By the late summer of 1945, some P-51Hs had been issued to a few operational units. These units were in the process of working up to operational status when the war in the Pacific ended with the Japanese surrender. None had the opportunity to see any combat. At the time of V-J Day, 555 P-51Hs had rolled off the Inglewood production lines. With the coming of peace, orders for 1445 more P-51Hs were cancelled, along with the entirety of the order for the Dallas-built P-51Ms after only one example (45-11743) had been completed.
- http://home.att.net/~jbaugher1/p51_13.html (http://home.att.net/~jbaugher1/p51_13.html)
From what I've read, three full Fighter Groups had made the conversion to the -51H when the war ended. It was the plan to completely replace the -51D with the -51H. Most things I've seen said the -51H was a much better dogfighter than the -51D because of its lighter frame and more powerful engine.
A F-51H from the Texas Air National Guard:
(http://www.mustangsmustangs.com/images3/Postwar/11.jpg)
* Sorry for going off topic (http://bbs.hitechcreations.com/smf/Smileys/default/biggrin.gif)
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Lt Col Dune
X.O. 352nd Fighter Group (http://www.352ndfightergroup.com)
"The Blue Nosed Bastards of Bodney"
"Credo quia absurdum est." (I believe it because it is unreasonable)
- The motto of the Republic of Baja Arizona
[This message has been edited by Dune (edited 10-20-2000).]
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I think Republic were the leaders when it came to turbo-supercharging. It was the Jug's great 'charger that allowed it to be the superior high-altitude fighter it was.
I just wish they had built the J model 47 for mass production.
"The P-47M was, essentially, developed collaterally with the XP-47J. The J was fitted with a high output version of the P&W R-2800. Specifically, the R-2800-57. This engine made 2,800 hp @ 2,800 rpm at 35,000 feet. This is in War Emergency Power. The aircraft actually attained 507 mph at an altitude of 34,300 feet. 2,800 hp is 133% of rated power. At military power (100%), the XP-47J could sustain 470 mph. 435 mph was attained at 81% of it's rated power (1,700 hp). All performance figures were obtained at 34,300 feet. The J model was an especially good climbing fighter too. It had a climb rate at sea level of 4,900 fpm. At 20,000 feet, it was still rocketing up at 4,400 fpm, and got there in 4 minutes, 15 seconds. Time to 30,000 feet was only 6 minutes, 45 seconds. Now that's an interceptor! Yet it had a usable range of 1,075 miles. Rather impressive performance. Nor was this a stripped down hotrod. It was fully armed and carried ballast in the wings equal to 267 rds per gun. The aircraft was flown to a height of 46,500 feet and was capable of a bit more."
(http://www.cradleofaviation.org/jordanpart7/xp47jcomp.jpg)
"Chief test pilot Lowery Brabham warms up the XP-47J prior to an early flight in November of 1943. Note the exceptionally tight cowling installation and spinner. This layout worked well, but was not adopted for production P-47s due to increased cost and complexity. However, a similar cowling was incorporated into the XP-72 little more than a year later."
Damn, too bad the AF cancelled that order. The spinner and cowl were not used on the M or N for simplicity of manufacture... shame.
How nasty would a 500 Mph Jug be? And talk about a Buff hunter.... under 7 minutes to 30k... woooo.
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Lephturn - Chief Trainer
A member of The Flying Pigs http://www.flyingpigs.com (http://www.flyingpigs.com)
(http://tuweb.ucis.dal.ca/~dconrad/ahf/lepht.gif)
"My P-47 is a pretty good ship, she took a round coming 'cross the Channel last trip.
Just thinking 'bout my baby and lettin' her rip, always got me through so far."
- Steve Earl
[This message has been edited by Lephturn (edited 10-20-2000).]
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Ok Enlighten me (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
The Jumo 213EB?
What production aircraft used that engine? I can find mention that the Ta152H's were using late series Jumo 213E's (and I can produce FW inflight test documents of their use) , but I can't find any information about the B subseries.
The DB605L?
Are you sure you don't mean the DB603L? The very late war Daimler Benz engine that was tested on the Ta152C, but was rejected because Daimler Benz couldn't get any off the production line?
Are we discussing true production engines here, or are we talking about very low numbers essentially handmade prototype engines?
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Vermillion
**MOL**, Men of Leisure
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And lets not forget the Brits here.
Not only were the Merlins and Griffons excellent, but the late engines manufactured by Napier-Sabre, the Centaurus I believe, were excellent (ala Hawker Sea Fury).
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Vermillion
**MOL**, Men of Leisure
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Originally posted by Jigster:
So...why was the Merlin mated with the 109 after the war? (http://bbs.hitechcreations.com/smf/Smileys/default/tongue.gif)
Because Spain had no DBs left.And it was not a problem only here, but also in other countries. Israel's Mezecs were me109Gs mated with Ju engines destined for bombers.
There weren't many DB engines around, in the postwar, yaknow.
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During durability testing of the C series R-2800 by Republic, it was decided to find out at what manifold pressure and carburetor temperature caused detonation. The technicians at Republic ran the engine at extreme boost pressures that produced 3,600 hp! But wait, it gets even more amazing. They ran it at 3,600 hp for 250 hours, without any failure! This was with common 100 octane avgas. No special fuels were used. Granted, the engines were largely used up, but survived without a single component failure. Try this with Rolls Royce Merlin or Allison V-1710 and see what happens
How about a Napier Sabre then?
The Sabre VII was similar to the V; the primary difference was the use of ADI and the strengthening of the internal components. From its 2238 cu.in. displacement a phenomenal 3500 hp was achieved at 3850 rpm. Finally, Napier testran a Sabre at 4000 hp with ADI.
I'd say we have a winner for output per cu. in. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
PS: What is ADI? I have no idea...
Vermillion; the DB 605L was the engine in the Me 109K-14 - the first one with a two-stage supercharger to improve high-alt performance. Oh, and the Centaurus was a Bristol radial sleeve-valve engine.
[This message has been edited by juzz (edited 10-20-2000).]
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Juzz, 109K14 ?? typo?
The K4 was last true production 109, with a "handful" of K6's that may or may not have been delieverd. Anything beyond that was never built.
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Vermillion
**MOL**, Men of Leisure
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If it wasn't built(at least prototypes), how come there is performance data for it? During beta there were Messerschmitt charts posted on this BB for the K-14 with DB 605L and D, using GM-1 and MW 50.
There was a recent thread on the K-14, do a search.
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Yes, and the threads conclusion was that beyond a few (less than 10) K6's nothing was produced beyond that.
I don't remember any Messerschmitt test data, but I have seen the posted test data of the FW factory tests of the Ta-152C prototype with the DB603L, with both MW50 and GM1. I am the one that scanned it and posted it. Its here: http://www.vermin.net/ta152/ta152-3.jpg (http://www.vermin.net/ta152/ta152-3.jpg)
Was there both a DB603L and a DB605L ?
I am at work and don't have any of my References, but here is what I have turned up from the net {which may or may not be accurate}
Just from a quick search of the net, I have found a reference of a prototype of the He219 that had DB603L's.
And I found this on the whole 109K Series thing.
Contrary to what has been written, no other variant of the K reached production or operational status. The rumors of use of the K-6 with its two Mk 108 wing cannon and the K-14 with the long anticipated DB605L are just that: rumors. The K-6 aircraft reached the prototype and testing stage but never entered production and no known operational test units were set up. The DB605L never got its problems sorted out and the test aircraft remained just that. All losses and strength returns that are know for 1945 show only K-4 aircraft.
at http://pol1.prairie.ca/~bigbear/khis.htm (http://pol1.prairie.ca/~bigbear/khis.htm)
Of course it all comes back to my first question. Are discussing production engines or prototype/one off's ?
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Vermillion
**MOL**, Men of Leisure
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The reason the P-47, P-38, etc. are smooth like that is because they're turbocharged. On the Daimlers, they do look different from other power curves, but they still have to change gears, and they still don't maintain power with altitude.
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Doug "Pyro" Balmos
HiTech Creations
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Vermillion: Hand-built prototypes, for everyone except Russia and Japan! (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
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Jumo 213EB, Ta 152H-1/Fw 190D-13.
There were K-14s albeit a very small number of them.
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If any of you guys have found some new evidence/documentation on the K14 I would love to see it, but everything I have seen up to this point said they never progressed beyond prototypes/blueprints
Hehe Juzz thats about right (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) What would you say if I told you that the Japanese produced an extremely innovative 440Mph+ fighter prototype in 2nd half of 1943 but shelved it when the prototype crashed on its 5th flight?
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Vermillion
**MOL**, Men of Leisure
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juzz Said:
> Vermillion: Hand-built prototypes, for
> everyone except Russia and Japan!
:-) Italy will rule the air in '43
M.C. 205N, Re2005, P.119, RO58 (five MG151's and one 12.7mg), P113 (a bomber with six 20m cannon and four 12.7mgs in powered turretts and a 10,560bomb load), M.B.902, flocks of little wood built S.A.I.403's...
Well, I can wish :-)
For my real perk choice, a P-40Q-2 or 3, for late war stall-fighter, 20,000ft in 4.8min, 422@ 20,500ft, and better vision than bubble canopy P-51/P-47's.
Not "Uber" at all.
MC202
Dino in Reno
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Vermilion; was that the one with two engines - one mid-mounted, coupled to the conventional nose-mounted engine to drive a single prop?
[This message has been edited by juzz (edited 10-20-2000).]
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Originally posted by chisel:
Nice to see the misinformation flowing freely.
Hydraulic clutch oil should heat up more at low altitude due to slippage.
Gasoline injection systems have little to do with Diesel injection (which incidentally, has been around a heck of alot longer)
Funked: Give the Germans 130 octane for the BMW/DB engine, Raise CR, boost, change the timing a bit. Then compare apples to apples.
I will grant you they were behind in exhaust driven supercharger technology tho,
First use of the injection pump for diesel engines was in the early 1920's. They weren't much smaller then the auxillary feed systems that made diesel engines useless in the first place.
First production of diesel engine that was small enough to fit in a vehicle was 1936.
The DB direct fuel port injection engine was prefected slightly before a practical set up for a diesel engine. For example, Me-109 was flying in 1935.
The systems were quite the simular...a mechanical driven system that providede a pressure feed (in the DB case, this allowed inverted operation) reduced the size of the diesel engine, by removing auxillary pressure systems for gravity feed.
It was rumored that a consultant for Catapillar was invited to view the DB production plant, saw the injection system, took what he learned back to US where they made there own system and prefected it.
The Diesel (compression) engine has been around longer then the gas engine. But Fuel injection was first developed for gas engines. It lead to smaller diesel engines, and by the end of WWII, most trucks, etc had them because of the economy, power, and durability. The exception are the Catapillar crawlers. The ones US engineers used had diesel engines, a rarity (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
But, Nearly every vehicle prior to the advancement of WWII was gasoline.
- Jig
Btw Ram I was kidding (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Yup Juzz, thats it !
Kawasaki Ki-64
powered by the Kawasaki Ha-201 (2,350hp) which was essentially two Ha-40 twelve cylinder liquid cooled engines monted in tandem for and aft of the pilots cockpit, and drove two contra-rotating three-blade propellors.
Kind of a single engine concept, combined with a P-39.
Empty weight at 8,929 lbs and loaded at 11,244 lbs. Wingloading was 37.3 lbs/sq ft, and power loading of 4.78 lbs/hp
Armament was 4 x HO-5 20mm cannons
Max speed was 429mph at 16,405 ft, and time to climb to 5k meters was 5.5 minutes.
This plane was as fast as a Mustang, similar if slightly better wingloading, much better acceleration and climb, and it had seriously better armament. Plus... NO torque !
And it would have been available in mid to late 1944, contemporary with the Mustang.
It could have changed the war, if they Japanese would have pursued the project further.
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Vermillion
**MOL**, Men of Leisure
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That DB engine is running a Bosch pump. Bosch went into series production in 1937 with the Gasoline injection system. 109 didnt fly with DB engine (109D) till 1937.
And Im 99% certain it was direct injection not port injection.
Robert Bosch did the Diesel Injection pump in 1927.
Cat stole the precombustion chamber from Sauer(sp?) in Switzerland. (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif)
Didnt Cat have a hand in that boat anchor that was the Chev 6.2?
[This message has been edited by chisel (edited 10-20-2000).]
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after midway, nothing could change the war vermillion
only way for japs to win was a short war. and midway enssured the war wasnt gonna be short.
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Pyro
I got no problem with your power curves but,
How does an infinitely variable hydraulic coupler 'change gears'?
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Originally posted by chisel:
Pyro
I got no problem with your power curves but,
How does an infinitely variable hydraulic coupler 'change gears'?
I bet that it has more to do with the shifting gear process than the actual shifting of the gears.
I am thinking it is like the "torque converter" for an automobile transmission. The torque converter does not shift gears. It allows the gears to be shifted in the transmission by providing an hydraulic cushion between the engine and the transmission.
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Mino
The Wrecking Crew
"Anyway, more golf..."
Humble