Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Boxman on July 09, 2009, 06:23:58 PM
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How do you take an engine from a lightweight fighter, (Spit) put it in a heavier fighter; and turn it into a high performance, long-range fighter?
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Lower drag and lots of fuel capacity.
Not the difference in their climb/acceleration and turn handling.
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How do you take an engine from a lightweight fighter, (Spit) put it in a heavier fighter; and turn it into a high performance, long-range fighter?
i wouldn't consider the p51 a high performance fighter.
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Lower drag and lots of fuel capacity.
This... From an aerodynamic perspective, the P-51 design was one of the most advanced of the war. It was one of the lowest drag airplanes built during the period. Its amazing to see what a difference the aero design can make on the same powerplant. Spits, for all of their good handling qualities, were really high-drag aircraft, at least until some of the late-model versions came out at the end of the war.
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High speed flaps, big fuel load and DT too if you need them, wing and body design. Great vis and guns.
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i wouldn't consider the p51 a high performance fighter.
I would. If flown to it's potential. There are different tactics for different planes.In a high speed dogfight the flaps alone can make a difference in the outcome. 1 notch of flaps at 350 IAS is high performance :t
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i wouldn't consider the p51 a high performance fighter.
You obviously have never flown in a P-51.
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i wouldn't consider the p51 a high performance fighter.
And what would you consider it to be?
ack-ack
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And what would you consider it to be?
ack-ack
a high alt flyer, given a few minutes and no other cons around the tables can be turned. if i come in co-e with a yak-9u or ki-84 i'm usually shooting him down or having to wave him goodbye.
the p51d has a good guns package and top end speed, it's only average in acceleration.
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a high alt flyer, given a few minutes and no other cons around the tables can be turned. if i come in co-e with a yak-9u or ki-84 i'm usually shooting him down or having to wave him goodbye.
the p51d has a good guns package and top end speed, it's only average in acceleration.
Take the fight up to 25K, up there is climbs 500ft/min better than the Yak9 and is probably 20-30 mph faster. Against the Ki-84 it's 50mph faster up there according to the charts. Granted the 51 would be at a disadvantage in a low speed turning fight on the deck but that's not the only measure of "performance".
Any 1940's area aircraft that could fly from London to Berlin fight and come home and had a top speed of 430-440mph at altitude is a high performance fighter, I think there's a hard time arguing contrary.
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Soulyss, you just confirmed Stran's conclusion that the P-51 is just a "high alt flyer".
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Soulyss, you just confirmed Stran's conclusion that the P-51 is just a "high alt flyer".
Isn't that what it was designed to do? :confused:
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Isn't that what it was designed to do? :confused:
Yes, but it seems some people here take exception to that.
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It is still high performance on the deck. It is faster than the Spit XIV at sea level despite the Mk XIV's monster engine.
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It really depends on how you define "performance". I'd say that the P-51 definitively is a performance fighter, but that its performance is of limited usefulness in the AH game environment. In the real world it was much more useful.
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It is the #1 fighter in AH tour after tour. Yes, some of that is due to fame, but fame alone wouldn't hold it there if it weren't also very capable. Some people just have this idea that it should out turn an A6M, out run an Me262 and out climb an Me163, after al it was "THE BEST FIGHTER OF WWII!!!"
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Yes, it "WON THE WAR (tm)"!
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Take the fight up to 25K,
Nooooooooooooooooooooooooooo!
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Nooooooooooooooooooooooooooo!
No? I'll admit it's been awhile since my Pony days but from what I remember it did pretty well up there.
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No? I'll admit it's been awhile since my Pony days but from what I remember it did pretty well up there.
I just don't want you puttin ideas of flying around at 25k in anyone's head. :D
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:lol
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What WE need are a buncha 25k bases! :aok
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What WE need are a buncha 25k bases! :aok
Can't do that as we don't have any duece-and-a-halfs, 5-tons, or bulldozers in AH. Maybe the up-date will include those?
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Alot has to do with the boost the vents give the aircraft, in most configurations it added 5-10mph more, also the paint being removed helped even more, paint was common place while airbases were still under threat from the germans and such.
simply put, lots o' things. :P
I have been reading a good book about the p-51's development, very interesting stuff.
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How do you take an engine from a lightweight fighter, (Spit) put it in a heavier fighter; and turn it into a high performance, long-range fighter?
supercharger
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supercharger
Spits had two stage superchargers as well as of the VII and on. In the end it was the wing design, the abilty to cram all that fuel into the 51 and the Merlin that did the trick. They did eventuall add small leading edge tanks in the Spit as well as a small fuselage tank, but it was never going to be in the amount that they were able to get in the 51, along with the 108 and 110 gallon drop tanks.
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supercharger
Where does the idea that Spits were low altitude fighters like P-39s come from?
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Where does the idea that Spits were low altitude fighters like P-39s come from?
Ignorance.
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It is the #1 fighter in AH tour after tour. Yes, some of that is due to fame, but fame alone wouldn't hold it there if it weren't also very capable. Some people just have this idea that it should out turn an A6M, out run an Me262 and out climb an Me163, after al it was "THE BEST FIGHTER OF WWII!!!"
No, we have the idea that it should out-turn a P-47 and out-accelerate a Tempest, because, oddly enough, they had that idea in WWII.
P-51 is just does not hang with the other 3 "most populars" as a fighter under MA conditions. It isn't up there with some fighters that have 20 ENY either. Its good but not so good as to explain its popularity or why it so greatly overshadows planes that can do the same job while bringing their own strengths to the table, like the D9, Typhoon, N Jug, or F4U-1A. Markets are never completely rational.
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In real life the P-51 had about 200-300 more hp from mid-1944 onwards. The modelled P-51's don't.
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What is the horsepower rating on the AH 51s?
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Two things that weren't mentioned in the fact that, for a same engine, one (the 51) is going faster than the other (the spit), I quote:
"One of the things that made the P-51 great was it's speed. This was accomplished by grinding the rivets on the skin of the plane flush with the surface of the skin. This made the surface of the plane smooth, no turbulence causing bumps. The other innovation was the cooling system. As opposed to a large radial air cooled engine (as on the F4U Corsair) the Mustang used a sleek V-12 with no vents on the nose. Instead the engine was liquid cooled, like most cars. The radiator was below and behind the pilot. Cold air was pulled in through a low-profile intake, after it passed through the radiator the cold air was held for a moment in a chamber where it was heated to very high temperatures by the engine heat. As the air expanded it forcefully "jetted" its self out an adjustable nozzle. This process allowed the Mustang to convert engine heat into thrust, making up for 95% of the drag caused by cooling the engine. (Cooling drag was the single biggest factor affecting aircraft speed at the time).
The design for the scoop is still used today in jet intakes. It was discovered that there is a thin layer of turbulence just off the skin of the aircraft. Putting an intake within this layer reduces its effectiveness. The Mustang's intake stood off the surface of the aircraft just enough to get an uninterrupted airflow. One can see this idea demonstrated in the F-16 and the F-4 among others."
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What is the horsepower rating on the AH 51s?
About 1,700 hp for the 1650-7 in the 51D.
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No, we have the idea that it should out-turn a P-47 and out-accelerate a Tempest, because, oddly enough, they had that idea in WWII.
Oddly enough, you're not the people I was talking about. I agree it should out turn the P-47 and Tempest and currently does not.
I was referring to the people who actually make claims close to what I posted. I have talked to some of them.
In real life the P-51 had about 200-300 more hp from mid-1944 onwards. The modelled P-51's don't.
Where did this power increase come from? If you mean 150 octane fuel, then many Allied aircraft got that.
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Why should a P-51 out turn a P-47?
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Why should a P-51 out turn a P-47?
Short answer
Wingloading at typical combat weights of 39lbs/foot vs. 41-43lbs/foot. The evidence compiled by WWII test pilots.
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Short answer
Wingloading at typical combat weights of 39lbs/foot vs. 41-43lbs/foot. The evidence compiled by WWII test pilots.
I really hope we don't' have to go through this again? Wingloading isn't everything...
As far as this goes: Two things that weren't mentioned in the fact that, for a same engine, one (the 51) is going faster than the other (the spit)...
You haven't read the entire thread...
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I really hope we don't' have to go through this again? Wingloading isn't everything...
We do not have to go through it again Stoney because I know what you are going to say, and then I am going to have to point out that the P-51's airfoil has a higher Clmax than the Corsairs, and etc. By God I know all the "P-51 wuz the leetest plane ever!" stuff on History Channel is annoying, but that doesn't mean we need to bend over backwards to justify an error in regards to the Mustang.
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We do not have to go through it again Stoney because I know what you are going to say, and then I am going to have to point out that the P-51's airfoil has a higher Clmax than the Corsairs, and etc. By God I know all the "P-51 wuz the leetest plane ever!" stuff on History Channel is annoying, but that doesn't mean we need to bend over backwards to justify an error in regards to the Mustang.
Its not justification of an error. You think Dale would let something go for so long that had been so hotly debated?
(http://i125.photobucket.com/albums/p61/stonewall74/Cl_Comparison_SL150MPH.jpg)
This is a graph of some XFOIL research I did a couple of years ago comparing the LA-7 and P-51. The information I had suggested that the LA-7 used a NACA 23015 airfoil at the root chord. So, for the purposes of this discussion, the airfoil comparison is the same since the Corsair and P-47 used the NACA 23015 airfoil at the root (the P-47 was a 23000 series slightly modified but close enough for comparison). You'll see that at the same exact parameters that NACA used to test airfoils in NACA 824, the 23015 has a higher Clmax than the 45-100 airfoil of the P-51D. This is purely the profile Clmax.
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Great info stoney
Helm ...out
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Now, this is where the P-51 airfoil had an advantage over almost all others, at least theoretically:
(http://i125.photobucket.com/albums/p61/stonewall74/Cd_Comparison_SL150MPH.jpg)
You'll see this is the drag coefficient plot over the same range of AoA, and at the same conditions of the earlier graph. You'll see that at low angles of attack, the P-51 has much lower profile drag than the 23015 airfoil, but at high angles of attack, the profile drag is much higher. This next chart shows the lift/drag curves of both airfoils plotted. This shows that at low angles of attack, the 45-100 has a much higher lift/drag ratio than the 23015, but at high angles of attack, the 23015 has a higher lift/drag ratio.
(http://i125.photobucket.com/albums/p61/stonewall74/LIFT_DRAG_SL150.jpg)
What does this mean ultimately? Not much without further analysis and additional considerations. However, it does show that you can have a very high performance airfoil shape that works very well over a very narrow range of angles of attack but is poorly suited to high AoA conditions. Could it impact the overall comparitive turning circle of the P-51 versus other higher wing-loaded aircraft? Perhaps. Again, we'd have to do some more research to know.
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I seem to recall it was Widewing who supplied the evidence that the P-51 is not turning as well as it ought to in comparison to the P-47 and Tempest at least.
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I would be curious to see what the evidence from Widewing says about P-51/P-47 comparative turn rates.
My impression from reading all the combat reports on Mike William's site, is that the P-51 turns better than the P-47 at low speeds, 220 MPH IAS or less, if using flaps, and it can certainly out-accelerates the P-47 in a wider turn.
At most usual combat speeds however, it clearly cannot out-turn the paddle-blade Razorback P-47, and in tests the German considered their captured early Razorback P-47D to be capable of significantly out-turning their 109G-6s. They make no such mention for the P-51B, and considered it's stall problematic... Note however that later bubble-top P-47Ds seem to perform noticeably less well in turns than the earlier Razorbacks, but still could hold their own against late '44 109s, if barely.
Against the 109G-6, the P-51's turning contests can last for ten minutes at a stretch (!) as long as the G-6 can spiral downward. Near the ground the superior turn acceleration of the P-51 gains it the upper hand quickly, unless the fight takes place in very late '44, where the acceleration in turns of the later 109s seems to get noticeably better, and turning fights resume going on forever... 10-15 360° turns are very common with P-51s, up to ten-fiften minutes(!) being reported.
Against P-47s, especially in the first half of '44, a very good 109G pilot, or group of pilots, will last 2-3 turns against a P-47D, before hurriedly calling it quits and breaking out of the turn... In line with German tests results for the Razorback at least, except that in right hand turns the P-47's margin seems to vanish... For some reason, right hand turns seemed a lot less common in combat.
The FW-190A, on the other hand, easily matches the paddle-blade P-47, and gets better in later '44, just as the P-47 gets worse. Both Russian and German tests agree on the FW-190A's turn being generally superior to the 109G, maybe even equalling the F, at least below 20k. This was probably accentuated on two wing gun 190s compared to four wing guns variants.
The most confounding thing I have found about the P-51, in reading 700+ P-51 combat reports, is the unreliability of its guns all the way through 1945, including on the D series... About 1 in 6 reports is affected by it in some way, sometimes the violent maneuvering leaving but one of six guns hammering away... The more violent the maneuvering the more jams, so especially prevalent against the 190... On the B model the problem takes on truly epidemic proportions, one being equipped with experimental field-made pneumatic "chargers", the pilot reporting unjamming his guns six times in the course of two 360° turns...
The P-47? Almost no jamming reported in 6-700 reports...
On that basis alone, as a U.S. pilot, I would RUN from a P-51... I guess the experience of firing live guns during hard-turning combat was not so prevalent in late '44 to taint the Mustang's reputation...
Gaston.
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Gaston, where do you come up with these fantasies?
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The most confounding thing I have found about the P-51, in reading 700+ P-51 combat reports, is the unreliability of its guns all the way through 1945, including on the D series... About 1 in 6 reports is affected by it in some way, sometimes the violent maneuvering leaving but one of six guns hammering away...
I've also found it amazing how unreliable the .50s were on Corsairs and F6Fs. It seemed to be more the rule than exception to have the guns jam in combat. The pilots had to often retreat from battle to get at least one gun working, as they jammed one by one during combat. That's one IRL feature I don't think the gamers want to the sims.
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Once they figured out how to mount the Hispanos in Spitfire wings I understand those had about one stoppage for every two thousand rounds fired.
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Two things that weren't mentioned in the fact that, for a same engine, one (the 51) is going faster than the other (the spit), I quote:
"One of the things that made the P-51 great was it's speed. This was accomplished by grinding the rivets on the skin of the plane flush with the surface of the skin. This made the surface of the plane smooth, no turbulence causing bumps. The other innovation was the cooling system. As opposed to a large radial air cooled engine (as on the F4U Corsair) the Mustang used a sleek V-12 with no vents on the nose. Instead the engine was liquid cooled, like most cars. The radiator was below and behind the pilot. Cold air was pulled in through a low-profile intake, after it passed through the radiator the cold air was held for a moment in a chamber where it was heated to very high temperatures by the engine heat. As the air expanded it forcefully "jetted" its self out an adjustable nozzle. This process allowed the Mustang to convert engine heat into thrust, making up for 95% of the drag caused by cooling the engine. (Cooling drag was the single biggest factor affecting aircraft speed at the time).
The design for the scoop is still used today in jet intakes. It was discovered that there is a thin layer of turbulence just off the skin of the aircraft. Putting an intake within this layer reduces its effectiveness. The Mustang's intake stood off the surface of the aircraft just enough to get an uninterrupted airflow. One can see this idea demonstrated in the F-16 and the F-4 among others."
The P-51's boundary-layer splitter was not in itself something new, nor was the so called "Meredith effect". Junkers discovered that thrust could be generated by radiator heat in the 1920s, and most radiator designs from the 1930s onwards made use of the Meredith effect and had boundary-layer splitters or ducts.
(http://109lair.hobbyvista.com/techref/systems/cooling/f_airflow.jpg)
The P-51 was so fast because it was a superbly aerodynamic design. Everything was shaped to minimize drag, including the wing profile at the expense of lift at high angle of attack. The only compromise was the bubble canopy starting with the D model. The P-51 cuts trough the air like no other WWII piston engine fighter. In comparison the Spitfire and 109 (especially the G-6) bludgeon their way through the air. The only planes that come close are the Russian Yak fighters; in Russia the need for streamlining was born not from the need for range, but from the need to get competitive speed with limited power.
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The P-51's boundary-layer splitter was not in itself something new, nor was the so called "Meredith effect". Junkers discovered that thrust could be generated by radiator heat in the 1920s, and most radiator designs from the 1930s onwards made use of the Meredith effect and had boundary-layer splitters or ducts.
(http://109lair.hobbyvista.com/techref/systems/cooling/f_airflow.jpg)
The P-51 was so fast because it was a superbly aerodynamic design. Everything was shaped to minimize drag, including the wing profile at the expense of lift at high angle of attack. The only compromise was the bubble canopy starting with the D model. The P-51 cuts trough the air like no other WWII piston engine fighter. In comparison the Spitfire and 109 (especially the G-6) bludgeon their way through the air. The only planes that come close are the Russian Yak fighters; in Russia the need for streamlining was born not from the need for range, but from the need to get competitive speed with limited power.
From Leonard "Kit" Carson, P-51 ace and test pilot:
"The most prominent speed secret was the dramatic reduction of cooling
drag. Placing the airscoop on the belly just in front of the rear edge
of the wing removed it as far as was practicable from the turbulence of
the prop and placed it in a high pressure zone which augmented air
inflow. Tests in the wind tunnel with the initial flush mounted scoop
were disappointing. There was so much turbulence that cooling was
inadequate and some doubted that the belly scoop would work. The
breakthrough was to space the scoop away from the surface of the belly
out of the turbulent boundary layer of the fuselage. Further testing
showed that spacing it further out would increase cooling but at a cost
to overall drag. Various wind tunnel tests established the spacing at
the current distance which represents the best compromise between
spacing out from the turbulent flow of the fuselage, drag and airflow.
With the flow into the scoop now smooth and relatively nonturbulent,
the duct leading to the radiator/oil cooler/intercooler was carefully
shaped to slow the air down (the duct shape moves from narrow to wide,
in other words a plenum chamber) enough from the high external speeds
to speeds through the heat exchangers that allowed the flow to extract
maximum heat from the coolant. As the air passed through the radiators
and became heated, it expanded. The duct shape aft of the radiator
forced this heated and expanded air into a narrow passage which gave it
considerable thrust as it exited the exhaust port. The exhaust port
incorporated a movable hinged door that opened automatically depending
on engine temperature to augment the airflow. The thrust realised from
this "jet" of heated air was first postulated by a British
aerodynamicist in 1935. The realization of thrust from suitably
shaped air coolant passages is named after him and called the "Meredith
Effect". Some have said that at certain altitudes and at a particular
power setting the Meredith effect was strong enough to actually
overcome all cooling drag; this is not regarded as being accurate by
most aerodynamicists. It greatly contributed to overall efficiency of
the cooling system but never equaled or overcame cooling drag. "
As to that image of the 109's cooling system.... I love how the artist shows the boundary layer conforming to the upper surface of the duct... In his dreams perhaps, but not in reality. You can bet all you own that the boundary layer (already very turbulent) immediately separated when it reached that 60 degree bend. There is almost no plenum volume to speak of either.
Back in the 1980s, we experimented extensively with radiator duct design on our two March Formula 2 chassis and quickly learned that you required a carefully shaped splitter to keep the boundary layer away from the inlet. Otherwise, it created tremendous turbulence and backpressure in the plenum, greatly reducing flow through the core. That in turn would require a larger core, adding unacceptable weight.
If anyone seriously thinks that the 109's radiators were as efficient as that of the P-51, they are deluding themselves.
My regards,
Widewing
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Widewing, the 109F's boundary-layer duct was separated from the radiator duct by a wall. The airflow did not have to "conform" to the upper surface of the duct, it was forced. The drawing does not show this very well.
Wright Field evaluation of Bf 109F: "Each flap is divided in two sections : the outer section is a modified split arrangement serving the additional purpose of controlling the airflow through the internally mounted wing radiators. At the front edge of the radiator is a hinged plate, linked with the trailing edge flaps to open with them. This plate picks up the boundary layer on the underside of the wing, and discharges it on the trailing edge. This form of boundary layer control causes smoother flow through the radiator, thereby reducing the area for proper cooling".
The "Meredith effect" would in fact more properly be called the "Junkers effect" as Junkers patented the diffuser-radiator-jet combination as "Düsenkühler" ('jet cooler') in DRP 299799 on 17 January, 1915. The principle obviously was well-known in the English-speaking part of the aviation industry as well. "Fundamentals of Fighter Design" by Ray Whitford notes (p. 61): "In 1926 it was realized that airflow through the radiators on liquid-cooled engines could, if properly ducted, eliminate the cooling drag and even produce a little thrust at speeds above 260 kts (483 km/h)."
Flugzeug Classic in one of their early issues quoted a speech given by Messerschmitt at some congress in the late 1930s in which he praised the Junkers jet cooler as the most important single contribution to high speed flight, as it cut down the otherwise prohibitive cooling drag, pointing out that the most advantageous way to incorporate the concept in a high-speed aircraft was in the form of wing radiators.
Even the old Hurricane had a boundary-layer splitter on its radiator intake, although it is not as pronounced as the Mustang's.
(http://www.airmuseumsuk.org/airshow/2004/Shut040502/800/images/018%20Hawker%20Sea%20Hurricane%20Ib.jpg)
Thrust recovery from radiator cooling was well known in the international aviation industry of the 1930s. If the Mustang's radiator was more efficient than other designs of its time it differed only in the particularly efficient way this well known principle was implemented.
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Widewing, the 109F's boundary-layer duct was separated from the radiator duct by a wall. The airflow did not have to "conform" to the upper surface of the duct, it was forced. The drawing does not show this very well.
Wright Field evaluation of Bf 109F: "Each flap is divided in two sections : the outer section is a modified split arrangement serving the additional purpose of controlling the airflow through the internally mounted wing radiators. At the front edge of the radiator is a hinged plate, linked with the trailing edge flaps to open with them. This plate picks up the boundary layer on the underside of the wing, and discharges it on the trailing edge. This form of boundary layer control causes smoother flow through the radiator, thereby reducing the area for proper cooling".
The problem is that based upon that illustration, unless that boundary layer divider extends onto or below the lower wing surface, the boundary layer will detach as it attempts to follow the sharp bend into the plenum. It absolutely will not make that turn without considerable turbulence. The volume of airflow making its way through that orifice will be minimal, although it should be uniform in flow at the outlet.
There is a very detailed and interesting Drag Analysis of the Bf 109 on Mike Williams' site that concludes that the drag associated with the 109's radiator design is "considered to be very high."
http://www.wwiiaircraftperformance.org/me109/Hoerner-Me_109.pdf (http://www.wwiiaircraftperformance.org/me109/Hoerner-Me_109.pdf)
My regards,
Widewing
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Germany had the most advanced wind tunnels in the 1930s and 40s, even one that could generate mach 3.3 wind speeds. I hardly think they made a boundary-layer duct that didn't work.
Now I direct your attention to this part of the quote that you obviously missed from my previous post: "At the front edge of the radiator is a hinged plate, linked with the trailing edge flaps to open with them. This plate picks up the boundary layer on the underside of the wing, and discharges it on the trailing edge."
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Hoerners study is actually a theoretical estimate of the drag percentage of the 109G, and is not based on actual measurements. Hoerner gives a drag coefficient of 0.036 for the Bf 109G, whereas the actual Messerschmitt polars IV/139/48 give 0.023, so Hoerners post-war study has some very obvious inaccuracies in his estimate.
In the G-series the boundary-layer ducts were deleted from the radiator design to increase production.
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Hoerners study is actually a theoretical estimate of the drag percentage of the 109G, and is not based on actual measurements. Hoerner gives a drag coefficient of 0.036 for the Bf 109G, whereas the actual Messerschmitt polars IV/139/48 give 0.023, so Hoerners post-war study has some very obvious inaccuracies in his estimate.
In the G-series the boundary-layer ducts were deleted from the radiator design to increase production.
In a relative sense, Hoerners data is spot-on. Given that he is considered THE expert on drag (that book the excerpt comes from is considered the Bible of Aerodynamic Drag), I'll take his observations with due regard. Sure, a theoretical analysis is different than sticking a full-sized model into a wind tunnel, but I bet Hoerner will be closer than anyone else, except perhaps Dave Lednicer, who now has the advantage of sophisticated CFD software. Seeing how Lednicer tested the P-51D 3D model on VSAERO and computed a .040 Cdwet and Hoerner manually computed a .040 Cdwet, I'd say Hoerner is as good a manual approximation as you can get. Just my opinion though...
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Germany had the most advanced wind tunnels in the 1930s and 40s, even one that could generate mach 3.3 wind speeds. I hardly think they made a boundary-layer duct that didn't work.
Now I direct your attention to this part of the quote that you obviously missed from my previous post: "At the front edge of the radiator is a hinged plate, linked with the trailing edge flaps to open with them. This plate picks up the boundary layer on the underside of the wing, and discharges it on the trailing edge."
I didn't miss the quote, I simply find it irrelevant. The drag analysis shows that the 109's radiator installation generated a great deal of drag.
Despite Germany's wind tunnels, they never came close to producing a propeller driven fighter with a drag coefficient anywhere near that of the 1940 vintage P-51. Why is that? Perhaps, is it because the 109G's radiator installation generates 16% of the fighter's total parasite drag? Compare that to the P-51D with less than 5%.
Also, those of you interested in the P-51 may find this stability analysis interesting... (huge link URL)
http://www.google.com/url?sa=t&source=web&ct=res&cd=3&url=http%3A%2F%2Faerosrv.atl.calpoly.edu%2Fjtso%2FAero%2520307%2F307-s05%2FSampleReport.doc&ei=tTNdSva-E5OuMKOIta4C&usg=AFQjCNEEn0fxZykkld19OeFYxAEa3KryDw&sig2=5BGV0_MALqaQmuiWfwbnZw (http://www.google.com/url?sa=t&source=web&ct=res&cd=3&url=http%3A%2F%2Faerosrv.atl.calpoly.edu%2Fjtso%2FAero%2520307%2F307-s05%2FSampleReport.doc&ei=tTNdSva-E5OuMKOIta4C&usg=AFQjCNEEn0fxZykkld19OeFYxAEa3KryDw&sig2=5BGV0_MALqaQmuiWfwbnZw)
My regards,
Widewing
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In a relative sense, Hoerners data is spot-on. Given that he is considered THE expert on drag (that book the excerpt comes from is considered the Bible of Aerodynamic Drag), I'll take his observations with due regard. Sure, a theoretical analysis is different than sticking a full-sized model into a wind tunnel, but I bet Hoerner will be closer than anyone else, except perhaps Dave Lednicer, who now has the advantage of sophisticated CFD software. Seeing how Lednicer tested the P-51D 3D model on VSAERO and computed a .040 Cdwet and Hoerner manually computed a .040 Cdwet, I'd say Hoerner is as good a manual approximation as you can get. Just my opinion though...
That may be so, but this time he was wrong. CD of 0.036 is close to a 109 tested carrying a 500 kg bomb.
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That may be so, but this time he was wrong. CD of 0.036 is close to a 109 tested carrying a 500 kg bomb.
LOLOLOL Yep, the world's foremost expert is wrong, you are right..
Smells like something died in the chicken coop.
My regards,
Widewing
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I didn't miss the quote, I simply find it irrelevant. The drag analysis shows that the 109's radiator installation generated a great deal of drag.
Despite Germany's wind tunnels, they never came close to producing a propeller driven fighter with a drag coefficient anywhere near that of the 1940 vintage P-51. Why is that? Perhaps, is it because the 109G's radiator installation generates 16% of the fighter's total parasite drag? Compare that to the P-51D with less than 5%.
Also, those of you interested in the P-51 may find this stability analysis interesting... (huge link URL)
http://www.google.com/url?sa=t&source=web&ct=res&cd=3&url=http%3A%2F%2Faerosrv.atl.calpoly.edu%2Fjtso%2FAero%2520307%2F307-s05%2FSampleReport.doc&ei=tTNdSva-E5OuMKOIta4C&usg=AFQjCNEEn0fxZykkld19OeFYxAEa3KryDw&sig2=5BGV0_MALqaQmuiWfwbnZw (http://www.google.com/url?sa=t&source=web&ct=res&cd=3&url=http%3A%2F%2Faerosrv.atl.calpoly.edu%2Fjtso%2FAero%2520307%2F307-s05%2FSampleReport.doc&ei=tTNdSva-E5OuMKOIta4C&usg=AFQjCNEEn0fxZykkld19OeFYxAEa3KryDw&sig2=5BGV0_MALqaQmuiWfwbnZw)
My regards,
Widewing
Your entire post is irrelevant. I've never argued that the P-51 wasn't aerodynamically superior. Quite the opposite in fact. Read my post again:
The P-51's boundary-layer splitter was not in itself something new, nor was the so called "Meredith effect". Junkers discovered that thrust could be generated by radiator heat in the 1920s, and most radiator designs from the 1930s onwards made use of the Meredith effect and had boundary-layer splitters or ducts.
(http://109lair.hobbyvista.com/techref/systems/cooling/f_airflow.jpg)
The P-51 was so fast because it was a superbly aerodynamic design. Everything was shaped to minimize drag, including the wing profile at the expense of lift at high angle of attack. The only compromise was the bubble canopy starting with the D model. The P-51 cuts trough the air like no other WWII piston engine fighter. In comparison the Spitfire and 109 (especially the G-6) bludgeon their way through the air. The only planes that come close are the Russian Yak fighters; in Russia the need for streamlining was born not from the need for range, but from the need to get competitive speed with limited power.
I'm only arguing that the technology used in the P-51, specifically the radiator, was nothing new. The P-51's radiator may have been more efficient than other designs of its time; to my knowledge a side-by-side comparison of the different radiators have never been made.
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LOLOLOL Yep, the world's foremost expert is wrong, you are right..
Smells like something died in the chicken coop.
My regards,
Widewing
So you'd take his estimate over test data?
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So you'd take his estimate over test data?
Show me the data for a service grade Bf 109G-6.
My regards,
Widewing
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Why should I need to? Hasn't this hijack gone on long enough? What in my posts on the P-51 was wrong?
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If concerned with aerodynamic efficiency, why not look at top speed vs Horsepower?
Me-109G-6, 1450 HP; 650 km/h
Me-109K-4, 1800 HP; 720 km/h
P-51D, 1700 HP; 705 km/h
P-51D, 2000 HP; 705 km/h(!) (But large speed and climb gains below critical altitude)
Spitfire IX, 1700 HP; 655 km/h
Spitfire IX, 2000 HP; 655 km/h(!) (But large speed and climb gains below critical altitude)
If any aircraft's aerodynamics should be made sport of, it's the Spitfire IX...
Where do I get what fantasies? That the P-47D out-turns the Me-109G-6 is from German captured tests in "On special missions; KG 200", recently published.
Yet the Germans were more impressed with the P-51B except for its handling in turns (one test pilot was killed)... The Razorback P-47 they had was below full power specs, and was not equipped with a paddle-blade prop.
Note that I don't say this is for ALL P-47 speeds or all P-47 props, or even for both turn directions. You might want to read the "P-47 encounter reports" on the Mike Williams site "WWII Aircraft Performance". I've read all 600-700 reports, plus the 700 or so for the P-51;
http://www.wwiiaircraftperformance.org/p-47/p-47-encounter-reports.html
You will see that for 109G pilots, being out-turned by P-47s was no fantasy, and a fairly quick deal, while the FW-190A can increasingly hold its own with it, and more, as 1944 turns into 1945. The P-51 "loses" the 190 quite often, but admittedly no real mention of being "out-turned". However, turning combats with Me-109Gs go on forever, which is never the case with the P-47...
That it is not widely known that the 190A out-turned the 109G, at least at lower speeds, is just an amazing durable prejudice based on simplistic maths...
Listen to what people who actually faced both in battle say;
http://www.ww2f.com/russia-war/21828-russian-combat-experiences-fw-190-a.html
Quote; "The FW-190 is more maneuverable in horizontal flight (than the Me-109)"
"The FW-190 does not like vertical combat"
"The FW-190 will inevitably offer turning combat at minimum speed"
I don't know what it would take for reality to make an intrusion...
The fact that the Japanese were highly impressed with the 190A should give anyone a loud clue...
Nakajima may have taken the 190 for inspiration to shorten by 8" the tail (and reduce by 3-4" all the tail surfaces chord) for ALL of its 5000+ Model 52 production, which is visible compared to the Mitsubishi production... (See my findings on this and the "Planes Of Fame" Nakajima in the August 2009 issue of "Model Aircraft Monthly")
As for the P-51's performance, I think the design of the radiator is the correct point to emphasize as a source of superiority in speed retention in turns, and in terms absolute speed at a fairly low power to weight ratio. The millionth of an inch tolerance supercharger is another thing that probably had no really comparable counterpart. On the Me-109's side, I would say the re-design of the oil cooler gaining 25-30 km/h on the G-10/K-4 is pretty remarkable...
It seems the 109 oil cooler was a bigger issue than the main glycol radiators...
Gaston
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Jesus Christ...
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Gaston,
Your Spitfire, Bf109 and P-51 numbers are all taken out of context. Which engines did each have?
Spitfires, being my strong point of the three, were not simply Mk IXs. Which engine are you talking about?
Spitfire F.Mk IX, Merlin 61, 1595hp, 657kph
Spitfire LF.Mk IX, Merlin 66, ~1700hp, 650kph
Spitfire HF.Mk IX Merlin 70, ~1700hp, 669kph
Spitfire F.Mk XIV, Griffon 65, 2050hp, 721kph
Bottom line is, the altitude an engine is optimized for will very greatly affect the maximum speed the airframe obtains.
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Thank you for the interesting topic and shared documents :aok
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Jesus Christ...
On this we agree.
Die Hard you and Widewing seem to be looking at different topics from what I read.
1. Is knowledge that the heat from a radiator can produced thrust as compared to a cold radiator.
2. Positioning of the radiator to create non turbulent air flow.
HiTech
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"It seems the 109 oil cooler was a bigger issue than the main glycol radiators..."
Well, this leads me to think of what was the cooling efficiency of the radiator module per sq in/cm (face and depth) in those aircraft?
I'd suppose that to know the actual drag of the radiator you need to know how draggy the actual heat transfer element is?
Or can you just make an assumption of a general heat transfer module drag figure and use that is calculations? Was there any progress in how these elements were made during WW2?
-C+
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That it is not widely known that the 190A out-turned the 109G, at least at lower speeds, is just an amazing durable prejudice based on simplistic maths...
Listen to what people who actually faced both in battle say;
http://www.ww2f.com/russia-war/21828-russian-combat-experiences-fw-190-a.html
Quote; "The FW-190 is more maneuverable in horizontal flight (than the Me-109)"
"The FW-190 does not like vertical combat"
"The FW-190 will inevitably offer turning combat at minimum speed"
I don't know what it would take for reality to make an intrusion...
Prove that the math is too simplistic.
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If concerned with aerodynamic efficiency, why not look at top speed vs Horsepower?
Because it does not take into account other factors that create or take away speed. If talking purely about aerodynamic efficiency, then Hoerner's use of wetted area versus drag coefficient is proper, as it tells you how efficiently the designers used the area of the design. Speed vs. Horsepower will be affected by propellor efficiency, exhaust thrust, etc. and would need to be normalized since not all aircraft make their best speed and/or best power at the same altitude. This last facet of the problem would be almost impossible to do. You can make a generalized comparison this way, but if you do, you have to understand that its really a poor method of comparison for aerodynamic efficiency, and caveat it as such. If, on the other hand, you wanted to make a comparison based purely on "best speed for available horsepower at sea level", then it would be a useful comparison to see which aircraft flew the fastest per horsepower at that altitude. But to attempt to draw further conclusions from it by itself would not be helpful.
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A point nobody seems to be talking about is weight.
P-51D empty weight was about 7635 pounds. Spitfire IX empty weight was 5610 pounds. 109G-6 weighed 5893 empty.
We all know that weight has a significant effect on turn radius and climb, as well as speed. At a higher weight, for a given airfoil, the angle of attack has to increase to increase the lift from the wing, thus increasing induced and parasitic drag.
Personally, I think that the design of the P-51 had to be absolutely phenomenally advanced to get more speed with the same HP at a TON heavier weight. Arguing about the whys and wherefores is beyond any of our technical ability--(my apologies to any degreed, experienced aeronautical engineers on the forum who have real world experience designing aerodynamic shapes) but the turn radius question would seem to me to be moot. There are so many factors involved in THAT calculation that I would guess nobody here can even list all of them, much less argue the details.
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The speed figures were offhand, but not too far off. I should have remembered the LF Spit IX was 650 km/h. It is the LF I intended to use as an example; +18lbs vs +25lbs...
The Me-109K speed is likely that of a MW-50 equipped version, which is a bit biased, as I think after the summer of '44 MW-50 boost became rare in Me-109 units. So rare in fact, that I know of two late war anectodes of FW-190As landing at Me-109 airstrips, and then being abandoned there because not one drop of the necessary C-3 fuel was available to move them... Without MW-50, 109s could use the lower octane B4, but the 190A HAD to use C-3.
Without MW-50, the 109K could probably do only 705 km/h or 710 km/h. It did have something called MW-30 that could combine with B4 fuel, but apparently the pilots were so inclined for the MW-30 tank to be used for regular fuel, that they often set the switch wrong and flooded the engine! The point I wanted to illustrate is that with a nearly identical airframe, with the same glycol rads but an improved oil cooler, the radiator drag was efficient enough to allow an increase in horsepower to be converted to extra absolute level speed, something totally missing from the Mk IX or even the P-51, but at least the P-51's speed limit was much higher to begin with.
I find the lack of absolute level speed increase with extra power very interesting in these two allied fighters, while their speed and climb gains below critical altitude are curiously large... Is this a peculiar characteristic of a highly boosted Merlin engine?
In any case, the Spitfire XIV was a near total redesign compared to the more modest Me-109K...
The point made by rshubert about the Mustang's weight is perfectly valid, and is in fact essential.
The Mustang radiator did not allow superior performance in absolute terms, but it allowed very good performance at high weights.
The extra weight allowed greater loitering time. And this long loitering time was catastrophic for the Luftwaffe, as even the Me-262 could fall victims to loafing Mustangs that knew where it had to come back. They didn't even have to risk staying within the base's flak reach.
This is the soccer equivalent of waiting around the net to kick the ball in, which is why this and other games have the "offside" rule, if I may be allowed this non-sport expert comparison...
The 109K could match or beat the P-51D in combat, I even think it had more than parity, but the fact that the P-51 could out-loiter it and then match it over its own territory, despite a 6 hour+ round trip, shows the real technological advance of the P-51's radiator. Despite the weight of fuel necessary for returning to England, the P-51 could perform and accelerate as though it was lighter, although not tighter-turning at many if not most speeds...
The radiator advantages did not apply directly to the turn rate, which was not comparatively very good except at very high speeds, (ie; at some speeds actually worse than a G-6 w/o gondolas), but it could somehow compensate for that by accelerating more in a wider turn, "gaining" from the outside, forcing a fast 109G-6 into a downward spiral, and tilting or swinging the nose inward at the last second to gain lead to fire (The flaps do seem to provide a significant, if brief, turn rate gain at some speeds). In the Mike Williams "P-51 encounters" collection, one pilot describes doing this to a 109G, and briefly stalling SIX times, each time he "swung" the nose in for lead, before finally scoring the first hits... I think this was another one of those fifteen minutes twelve rounders that practically never occur in a P-47 vs 109G match...
A FW-190A is in a similar predicament as the 109G against the P-51 at high speeds, except that its turn rate at these higher speeds would not match the P-51 for a very long time, even with the help of a downward spiral. A long high speed battle would probably have to include many roll reversals. One actual Western Front FW-190A-8 ace on these boards was quoted as saying that preparing for battle with P-51s was done by downthrottling the speed and popping the flaps for low speed BEFORE the merge, either to set up a series of head-to-heads, or for stall fighting. Quite eye-opening. He describes out-turning and dispatching a tailing P-51D in two 360° turns at low speed...
Later in the war, 109G-10s and K-4s for the first time really matched, or "out-turned", the P-51 without spiraling down, strictly because of greater engine acceleration. They otherwise did not turn any tighter than the G-6.
You never hear anything like this with the paddle-blade P-47 vs 109G contest... On the contrary, the problem with the 109G, for the P-47, is that the P-47 often turns inside a little too much and starts to overrun too close, losing the target under the cowl. Except at high speeds, the P-47 has much more parity, or trouble, with the 190A, and this gets noticeably worse towards late '44. It also seems the later bubble top Jug is much heavier than the Razorback, and is not as good a dogfighter. I don't know what the exact weights are, but there might be a significant difference, and again greater engine power might have allowed a larger but faster circle to muddy things up...
As for the 109G-6's qualities, note that it is *implied* in the above Russian 190 evaluation that the 109 likes vertical maneuvers better, and that it is less stereotyped in what it can do. Besides better altitude performance, I am sure the 109G without gondolas can out-turn the 190A at higher speeds, where the 190A can start harder but will mush and lose speed more rapidly. At these higher speeds, the 109G-6 still loses more speed than a Mustang, and has to spiral down. At lower speeds it supposedly can out-spiral climb the Mustang (Steinhoff), but examples of this appear rare... The two German fighters do complement one another in many ways, as Rall said.
Note that I am as puzzled as anyone here as to why the P-47D and FW-190A can decisively out-turn my favourite, the Me-109G! This at different, but large, ranges of speeds... See the allied test below to see which one does which;
http://img105.imageshack.us/img105/3950/pag20pl.jpg
Note that U.S. Navy tests on the Mike Williams site do appear to contradict some of the above test and statements, with a fully dismantled 190F ballasted as an A-5, that never worked properly when it was reassembled... This Navy tests was actually officially contested by the British Farnborough test establishement as to the roll rate conclusions, which roll rate on the 190 affects greatly low speed turn performance ("catching" the stall etc..). Also the F6F and the F4U are likely better turn fighters than the P-51 or P-47...
As to why can a P-51 can out-accelerate a 109G-6 while in a slightly or significantly wider turn, but not while climbing, I have no real clue either. Isn't acceleration the same in all directions?
I know much of this is not widely accepted, to put it mildly, but I really wonder just how well do we know these machines, when for instance a 1989 warbird flight test by seasoned test pilots yields results very much at odds with most previous "knowledge", especially concerning the P-51;
http://bbs.hitechcreations.com/smf/index.php/topic,261798.0.html
Here is the thread I started on this issue; http://bbs.hitechcreations.com/smf/index.php/topic,263700.0.html
For another example of surprises, pick up the next August issue "Model Aircraft Monthly", and see, with photos and drawings, my letter on how "experts" have missed a fully redesigned 8" shorter tail on 5000+ Zeroes...
Even the Zero's chief designer, Jiro Horikoshi, makes absolutely no mention of this in his biography "Eagles of Mitsubishi". I think it is likely he didn't even know what Nakajima did with "his" aircraft...
I tell you, sometimes, we are more in the dark than we think...
Gaston
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The Me-109K speed is likely that of a MW-50 equipped version, which is a bit biased, as I think after the summer of '44 MW-50 boost became rare in Me-109 units. So rare in fact, that I know of two late war anectodes of FW-190As landing at Me-109 airstrips, and then being abandoned there because not one drop of the necessary C-3 fuel was available to move them... Without MW-50, 109s could use the lower octane B4, but the 190A HAD to use C-3.
That is so wrong that I almost suspect you're being deliberately obtuse.
MW50 was standard on all G-14, G-10 and K-4 109's. The 109 could use B4 fuel with or without MW50, but without MW50 maximum manifold pressure was severely reduced. The 109K-4 modelled in AH runs on B4 fuel + MW50 at 1.8 ata producing 1,850 PS. With C3 fuel and MW50 the boost could be increased to 1.98 ata and 2,000 PS.
You're full of it.
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gaston,
You don't know what you are talking about. My whole point of posting those Spitfire speeds was to show you how stupid it was to use that as a tool to determine aerodynamics. What you are looking at when you try to use that as a tool is mainly where the engine's full throttle altitude is, or do you think the Spitfire XIV magically gained 70kph from 50 more hp when compared to your 2000hp Spitfire Mk IX? You can't compare the Bf109K-4 with a Spitfire LF.Mk IX and get meaningful data about how their aerodyamics compare just by looking at their top speed and horsepower.
Oh yes, the Spitfire XIV was most definately not a full redesign. It was a Spitfire Mk VIII with a Griffon 65 strapped to it and a somewhat larger vertical stabilizer and larger radiators, which actually gives the Mk XIV worse aerodynamics than the Mk VIII or Mk IX. The full redesign of the Spitfire starts with the Spitfire F.21.
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I think this is the thread where flat turns were mentioned.
What is a 'flat turn'?
a. a turn where the wings stay level and the rudder is used to change direction
b. a turn that is a loop in the horizontal plane
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I think this is the thread where flat turns were mentioned.
What is a 'flat turn'?
a. a turn where the wings stay level and the rudder is used to change direction
b. a turn that is a loop in the horizontal plane
Milo I assume you are joking, but a flat turn is one that the plane is staying at the same altitude.
HiTech
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Milo I assume you are joking, but a flat turn is one that the plane is staying at the same altitude.
HiTech
So an a/c banks so the wings are not level, then elevator is applied and a circle is turned. Some top rudder is applied so no altitude is lost. I would call than a horizontal loop if the a/c keeps turning.
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Milo The rudder does not control the altitude the Elevator does even if in a bank.
Do a little search on basic flight dynamics , but to put it very simply.
To fly level (not descending not ascending) you need a force = to the weight of the plane in the up direction. I.E. 1g of force.
As you bank the plane the 1g of force that is normally straight up now is some what to the side but also some what up.
The amount of up force in the up direction is the cos of the bank angle * the lift.
Even with out moving the elevator the plane starts to turn, but also descends.
You apply elevator to increase lift in both the direction of the turn until the amount of force straight up is again 1g.
Rudder is used to eliminate any side force on the plane (I.E. ball centered) so that all force is threw your but.
HiTech
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MiloMorai, in a normal bank turn you don't use rudder to "hold up the nose" like that. You actually rudder into the turn to avoid side-slipping. What you describe is not used except during the so-called "knife edge" where your wings are at or close to 90 degrees on the horizon, but you're not turning then. Unless you're trying to bleed off some speed you're better off leveling the wings a little to get the nose up rather than using the rudder.
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Just don't rudder into the turn too much :devil
Was used as an escape plan. Stall turn, boot on rudder and the aircraft will flip with nose down, let it go, twist and recover.
Evil. :t
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Karnak,
Sure the Spit Mk XIV had a higher critical altitude than a +25 lbs LF Mk IX, which accounts for SOME of the speed difference. But it was faster at ALL altitudes with basically the same power, so its aerodynamics could not have been worse, especially considering its heavier weight!
From 67" hg to 80" hg, or 1700 hp to 2000 hp, the V1650-7 engine of the Mustang has NO difference in critical altitude, yet the absolute speed does not increase at all with 300 extra hp, but it does massively so below critical altitude, as does the climb rate. So the top speed is less of a "peak".
The same thing occurs on the Spit IX. Whatever the reason for this, this is unique to the Merlin P-51 and Spit IX, and completely unlike what happens with most other fighters... Below 25K, an LF Spit IX with +25lbs (2000 hp) will easily beat the climb rate of a 1800 hp Me-109K. In the same way, it will also easily beat the climb rate of the Mk XIV at +18 lbs! Yet at the same time its top speed is about 70 km/h slower than either... If that's not an aerodynamic deficiency, what is?
A MK VIII with a Gryphon tacked on? How about re-stressed wings, re-stressed engine mounts and fuselage, increased tail lenght and fin surface, and totally re-designed radiators? Compared to all that, Me-109K really is a G-6 with another engine tacked on...
Diehard, you could be correct that the 109K could use MW-50 with B4 fuel, but earlier 109s could not have the full 1800 hp without combining MW-50 with C-3 fuel.
MW-50 had many disadvantages; it could not be used in prolonged climbs or prolonged dives without damaging or destroying the engine. This not a good thing for low time pilots... It also increased maintenance and added weight.
1.98 ata was used only experimentally, or on a trial run basis, in a very few units in 1945; this has been discussed many times already...
Note that on the 109, full MW-50 power could not be used at prolonged nose-up angles without compromising oil circulation. So it could not add to the sustained climb rate, and it would blow up the engine in prolonged dives...
That could have something to do with the absence of MW-50 climb rate charts...
A strong indication of the rarity of MW-50 use in Me-109 units, after the Summer of '44 at least, is the fact that Russians tested their captured Me-109Ks without it. If they didn't use it, why test it?
While 109s could and did use MW-50 late in the war, "standard" installation does not mean standard use.
I guess this is a grey area where you choose your leaning...
Gaston
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DB 605 A(M) Standard fighter engine, up to 1475 PS, 605 AM with MW-50 system up to 1800 PS
DB 605 B Same as 605 A but for use in twin-engined aircraft like Messerschmitt Bf 110
DB 605 AS(M) Altitude optimized version of 605 A using the larger DB 603
Daimler-Benz DB 603
DB 605 ASB(M) Altitude optimized late-war version of 605 AS using B4 fuel, ASBM with MW-50 system and up to 1800 PS
DB 605 ASC(M) Altitude optimized late-war version of 605 AS using C3 fuel, ASCM with MW-50 system and up to 2000 PS
DB 605 DM First DB 605 D version, standard MW-50 equipment, up to 1700 PS
DB 605 DBM Improved 605 DM, standard MW-50 equipment, first version up to 1850 PS, later reduced to 1800 PS, B4 fuel
DB 605 DCM Improved 605 DM, standard MW-50 equipment, up to 2000 PS, C3 fuel
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Didn't someone post a document showing clearance for a couple of K4 flights (JG54?) for the last months of the war?
http://forum.12oclockhigh.net/showthread.php?t=2470
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Didn't someone post a document showing clearance for a couple of K4 flights (JG54?) for the last months of the war?
http://forum.12oclockhigh.net/showthread.php?t=2470
Yes it was for 4 Gruppen with ~150-160 a/c and 60-70 operational.
OKL, Lw.-Führüngstab, Nr. 937/45 gKdos.(op) 20.03.45
I. / JG 27 Bf 109 K-4 no change boost increase to 1.98 ata
III. / JG 27 Bf 109 G-10 no change boost increase to 1.98 ata
III. / JG 53 Bf 109 K-4 no change boost increase to 1.98 ata
IV. / JG 53 Bf 109 K-4 no change boost increase to 1.98 ata
Now if you believe Kurfurst, all the a/c were converted but we all know how well he can be trusted. :rolleyes: There is also the lack of C3 fuel, which was needed by Fw190 units.
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How do you take an engine from a lightweight fighter, (Spit) put it in a heavier fighter; and turn it into a high performance, long-range fighter?
Well, first off is that the pony has less drag, and high fule capacity. Second is the Pony isn't THAT much bigger. The pony can't climb as well, accelerate as well, and can't turn as well. And remember, the pony is the fastest only at mid alts, not low alts; the drag might have something to do with it.
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See Rule #4 (trolling)
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See Rule #4 (trolling)
You keep saying this, yet you have not offered a single shred of evidence to back up your claims.
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You keep saying this, yet you have not offered a single shred of evidence to back up your claims.
Hey just right there! The TV-show said, the P51 won the war! Loser :lol
j/k
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See Rule #4 (trolling)
There is still no fact in this, just an opinion...
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I say we take a vote.
All that agree with Lusche: (a simply stagering volume of agrement)
All that dissagree *R 105* I do... (cricket chirping)
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The "under-modeled" theory comes from people watching too much Dogfights... Reason the P-51 was considered so great during WWII was because pilots flew it to its strengths.. They kept it high and fast, surprise attacks from high above were common and wing man tactics were almost essential..
It could fly at speeds where other planes were virtually uncontrollable.. 9/10 times, P-51 could dive or zoom away to escape pretty much any attack which, in turn, attributed to it's high survival rate.. This is all how many Pony sticks in the game utilize the P-51.. So, not sure where the whole under-modeled thing is really viable... I'm sure there is some practically insignificant trivial little thing that anyone could find.. But, for the most part, I think we have a fairly accurate representation of both the B and D Mustangs...
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When the overall drag model was revised, the P-51s took a big hit. A reduction in turn radius and a significant loss of turn rate using flaps was the result. I have tested this against a late version of AH1. Prior to this, the P-51s could out-turn the P-47D-25 and -40. That is no longer the case. Back then, you could dump flaps and maneuver with much of the plane set. That is no longer feasible.
That drag modeling change presented a significant change in drag associated with flaps for numerous fighters. Some suffered badly, such as the Ki-61 as well as the C.202 and C.205. Others saw a huge shift the opposite way. These include the Bf 109s. Other effects were observed. For example, the F4Us became more stable in the roll axis than the F6F-5, which is historically inaccurate. Some improved, some got worse, but the majority didn't change at all.
That said, I'd like to see increased torque effect throughout the plane set. Most are too easy to fly at low speeds.
The reality is that there will never be a perfect correlation to the real world. The level of research required for that is staggering. The volume of data to be sifted through is daunting, and much of it conflicts with other data. I have no doubt that issues will gradually be addressed, but only on a priority basis. Obvious problems are quickly fixed (the P-38 and P-39 flap drag problems were fixed with the next respective patches).
USAAF fighters were engineered for best performance at medium to high altitudes. Most of the action in the MAs occurs at low altitude, under 10k and mostly below 5k.
Down there, the best fighters are those engineered for that realm. For example, below 10k, the P-39Q will slice and dice the Lightnings, Jugs and Mustangs. At 12k, it's as fast as the P-38J and P-47D. The P-39Q out-turns all of these with ease.
Gentlemen, it is what it is. Adapt to it. Adjust your tactics to suit the aircraft. P-51s can not longer stall-fight 109s. So, don't attempt it. Keep it fast, use its superior E-bleed characteristics to maintain a speed advantage or keep it near its corner speed, where it is very effective.
My regards,
Widewing
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keep it fast, use its superior E-bleed characteristics to maintain a speed advantage or keep it near its corner speed, where it is very effective.
Yes, but be prepared to be called a runstang pilot. When you do decide to get slow and you beat them, be prepared to be called lucky.. or a cheater. :aok
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USAAF fighters were engineered for best performance at medium to high altitudes. Most of the action in the MAs occurs at low altitude, under 10k and mostly below 5k.
Down there, the best fighters are those engineered for that realm. For example, below 10k, the P-39Q will slice and dice the Lightnings, Jugs and Mustangs. At 12k, it's as fast as the P-38J and P-47D. The P-39Q out-turns all of these with ease.
Gentlemen, it is what it is. Adapt to it. Adjust your tactics to suit the aircraft. P-51s can not longer stall-fight 109s. So, don't attempt it. Keep it fast, use its superior E-bleed characteristics to maintain a speed advantage or keep it near its corner speed, where it is very effective.
My regards,
Widewing
This is the part I think most folks don't take into consideration. The AH MA airwar is flown at lower alts then the actual WW2 airwar most of us read about. Planes perform differently at different altitudes. The Spit LFXVIe was purpose built for lower alt work as it was going to be supporting the guys on the ground. The 39 as Widewing mentioned, was much better at lower alts were the lack of supercharger was not a factor. The list goes on and on. What the 51 did up high, vs what it does down low is going to be different. That being said, I've seen some guys move that cartoon 51 of ours very well down low and even low and slow.
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Guys,
I would like to point out that the P-51D in Aces High is often judged in conditions that rarely if ever existed in real life.
Given a lead and wingman well versed in wing tactics, the P-51D flown to its strengths is a formidable fighter. Such a team in the MA's can consistently fly sorties where each pilot can pick up 6 or 7 kills with one ammo load, and RTB dragging multiple enemies in a "rolling defense" and still land safely.
There are many players who can take a single inferior aircraft into a furball and still land multiple kills.
But if I wanted to do that consistently, the P-51D and a good wingman (in my opinion) is the best choice.
The strengths of the P-51D, it's high speed performance, combined with well trained pilots using co-ordinated wing tactics is what made it great. If you separate the individual elements you lose the synergy that made it all work.
Badboy