Bf-109 vs Spitfire vs Fw-190 vs P-51
- Thread starter Soren
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Some time ago Tomo stated that the Spitfire XIV and Tempest etc. would eat the Fw 190D-9 "for breakfast" whereas almost every source that I read so far (many on this forum) mentioned
at least parity of the latter compared to the formers.
Also in polls here on the board the Dora got very high points, often higher than some of its allied contemporaries. I don't know if these can be seen as exemplary.
So why such contradictory statements?
I asked this before but the responses were not very clear.
Maybe some of you can enlighten now.
at least parity of the latter compared to the formers.
Also in polls here on the board the Dora got very high points, often higher than some of its allied contemporaries. I don't know if these can be seen as exemplary.
So why such contradictory statements?
I asked this before but the responses were not very clear.
Maybe some of you can enlighten now.
drgondog
Major
I have autographed copies of both "Logbook" and "Gunther Rall" - wonder what They are worth?
bobbysocks
Chief Master Sergeant
i would not even venture a guess but what ever they are worth now...will only appreciate. i would make sure they are kept safe and preserved.
airminded88
Airman 1st Class
Bought and read 'The men who killed the LW' a couple of years ago, very informative and well written book... Then, the former girlfriend borrowed it because she wanted to 'take a look at it', I broke up with her, moved away overnight and took the book with her and never even got past the first chapter... so yeah, think twice before lending your books to people that don't realize the valuable items they have in their hands.
I specially appreciated the fact that the author links all AAF campaigns simultaneously, from the early fighting in North Africa all the way through the final battles over central Germany engaging jet fighters.
First hand accounts are gripping.
I specially appreciated the fact that the author links all AAF campaigns simultaneously, from the early fighting in North Africa all the way through the final battles over central Germany engaging jet fighters.
First hand accounts are gripping.
The Fw 190D9 was a Fw 190A9 with the BMW801TS radial engine replaced by the Jumo 213A inverted V12. A small plug was inserted near the empenage to lengthen the tail moment arm so as to compensate for the longer nose and the C of G and pressure chances it caused. It was a simple 20cm extension.
The basic Jumo 213A only had 1750hp, actually less than the BMW801TS. However it did have a small inter-cooler which helped achieve slightly better high altitude performance. It also went through three field upgrades of emergency 'boost'
Upgrade 1: rich mixture injection of 87 octane fuel into the eye of the supercharger to precool the mixture. This took the engine to 1900hp.
Upgrade 2: MW50 injection, the "Oldenburg" system in which Methanol-Water MW50 was blown into the supercharger compressor by pressurizing the MW50 tank using air from the supercharger.
This system was fitted by Luftwaffe service crew, the "blackbirds". Mostly fitted out by December 1944.
Upgrade 3: MW50 high flow injection using a pump driven system, this system was fitted in the field by Junkers personnel around Jan 45.
Hence Fw 190D9 performance trial range in speed from 398mph to 437mph at full throttle height.
In addition there were also allowable boost to 2 or more ata increases from other improvements and improvements to the engine seal gap.
Remember when comparing speeds of aircraft that some aircraft, those with two speed instead of single speed superchargers and those with two stage superchargers only have a superior speed at high altitude.
One must consider altitude when comparing 'which is better' scenarios.
In the case of the Fw 190D9, it was powered by the Jumo 213A a single stage two speed supercharger engine that gave it an advantage over the tempest at medium altitude. The Jumo 213A however was a bomber engine being recycled from Ju 188 production.
The definitive D series was really the Fw 190D-13 which had the Jumo 213F engine. The "F" had a better propeller, it had mountings for a propeller hub 20mm gun (which allowed the draggy synchronized cowling guns to be deleted) more importantly it had a two stage three speed supercharger and all of the boost systems preinstalled. A few did get delivered and flown. The D12 merely used a 30mm prop hub gun.
This version was good for 452 mph.
The Jumo 213F had been created from the Jumo 213E (used on the Ta 152) by deleting the large inter-cooler and using higher octane C3 fuel. The Jumo 213A had an intercooler but the one on the Jumo 213F was either too small or absent. An engine called the Jumo 213EB added an small intercooler and some minor mods to the valve size. This powerful engine was to be added to the Fw 190D13/R25 and was expected to achieve 478mph at critical altitude and 393mph at sea level. It was slated for delivery in April. The "R25" term indicates this is a field Retrofit. I.E. it could be fitted to existing Fw 190D13 by Luftwaffe field technicians. This speed is the same as a P-51H.
Fw 190D9 did achieve over 387mph at sea level simply using 2.0 ata boost but don't know if this was used in service. The Jumo 213 with two stage x 3 speed supercharger did improve high altitude capability.
The Fock-Wulf 190D9 with the single stage supercharger, in typical squadron condition in December 1944 with MW50 could do 370mph. It would have been slightly faster than most P-47D/M/N at sea level. It was however slower than the Tempest V and P-51 when those aircraft were using 100/150 though it was faster at altitude than the Tempest V though slower than the P-47 and P-51 with 100/150. It was slightly faster, 10mph, than the Spitfire XIV at 18psig at low altitude though would have been slower if the Spitfire XIV was using 25psig (which it couldn't have been till March 1945 I believe)
The Focke-Wulf 190, like the P-47, didn't have laminar flow wings, so it was at a disadvantage in thick air where drag was paramount. However getting over 400mph at sea level seems quite difficult even for the laminar flow wings of the P-51 and Tempest and the speed gap was small.
The EB engine would likely have made it to the Ta 152, which being heavier and bigger lost about 10mph at low altitude. However the big, efficient high aspect ratio wings had 3 degrees of washout and it's said the aircraft was controllable in the stall due to this and had a very good turning circle.
The Fw 190D9 was flown by US pilots who reported it had a gentle controllable stall with plenty of warning with power on though regarded as lacking in turning circle. Probably wing loading was too high. There was an enlarged wing planed for the Fw 190A series with the Fw 190A-10 and it could have been fitted to the D series but it just makes more sense to go with the Ta 152 series which has already increased wing size.
Beyond the Jumo 213EB there was the Jumo 213J which was benching over 2600hp, I believe it was taken to Rolls-Royce and exceeded the Griffon in RPM and power.
It seems the Germans fell behind in engine performance from mid 1942 when the Merlin 61 came in. They started closing the gap from early 1944 when the Db605ASM engine came in as well as boosted versions of the BMW801 and probably closed the gap by early 1945 maybe even beating allied engine makers in some ways though they seldom deployed in numbers.
In May 1942 the Me 309 was flown with a Laminar flow wing. It did achieve a spectacular speed of 462mph though its maneuverability was said to be disappointing compared to the Me 109. This I assume was either an power to weight ratio issue or caused by too small a wing.
A redesign probably would have fixed any issues and allowed deployment two years latter, same time as the Tempest V but but by this time Milch was betting on the jet engine. He is on record as saying that Germany would loose the war if Me 262 did not enter service in 1943.
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The extension was 50 cm long, per Rodeike's book, pg. 378.
There was no intercooler in the Jumo 213A installation. The better high altitude performance, D-9 vs A-8/A-9 was due to several reasons: less engine/cooling drag, better use of ram through external intake, availability of greater ammount of exhaust thrust. Having two cannons less compensated for increased drag of the external intake.
Naming those upgrades as 'filed upgrades' is a bit misleading. Rodeike states that those upgrades were undertaken by the TAM (Techinsche Aussendiens/Motorenbau) 'organzation'. The chages were noted as 'Rustsatze', and indeed many of the changes were undertaken in the field, ie. in the air bases.
Same source (pg. 379) states that 1900 PS was achieved though simple overboosting, not the fuel injection in the supercharger('1900 PS durch die Ladedruckerhoheung festgelegt').
Hopefully someone might shed some light to what the TAM really was, and how it functioned?
Agreed. 2.02 ata was achieved through use of MW-50.
The Sabre in Typhoon/Tempest was outfitted with single stage, two speed supercharger. At 12-17000 ft, the D-9 was a bit faster, under and above that altitude belt the Tempest was faster.
Again, the Jumo 213A did not have an intercooler, and it was also not used on the 213F.
Even the best prop-driven aircraft were 'hitting the wall' above 470-480 mph.
Benefit of the Fw was that it was, compared with those allied fighters, quite a small aircraft. It would be fast even on moderate engine power, let alone once 2000 PS+ was available.
German engines were in disadvantage above 20000 ft (even with their big displacement, high compression ratio engines, that were turning decent RPM) once Allies started introducing 2-stage engines. No matter how much the BMW-801 was boosted, it won't help it above 20000 ft. The DB-605AS with a big supercharger was a step forward, even if it was too late, the ASM still a bit later in service. The 605L (with two stage S/C) was still managing some 300 PS more at 10 km vs. the 605D, but the 605L was a really late comer.
Sticking great loads of armament and armor to the Fw-190 will certainly not make it a performer, either.
Germany lost the war once they declared war on the US, while being in the same time in war with UK and USSR.
Bad-Karma
Airman 1st Class
Hate to bump such an old thread but I was curious if anybody continued trying to do the actual calculations Drgondog and Soren were working on. I know Soren is now banned an Drgondog wasn't really interested in the time it would take but curious if anything changed in the few years this thread has been running haha.
drgondog
Major
I actually piddled in establishing a spreadsheet but the lack of source documents (in my hands) to get the following was unsuccessful. I felt like I needed, by airframe
1.) Form drag data based on AoA to see what was happening as aircraft entered a sustained turn at speeds higher than they could achieve for max turn rate for zero loss in altitude.
2.) Propeller Efficiencies (actual calcs that would be more suitable than 'assume .85') as well as different engine thrust expectations as a function of boost and HP for the respective fighters and models.
3.) Some insight to the actual contributions of LE slats on the Bf 109 in a high G bank. Whatever it is, it certainly is not the high CLmax Soren was touting, nor can one extrapolate CLmax calculated for level flight/clean stall conditions.
These factors, IMO, are necessary - at least to evaluate order of magnitude influence - to derive
A. Thrust of the engine at speeds well below Vmax - in ranges not optimized for the Propeller.
For the Exhaust contribution to THAT 'thrust system' at HPmax, Horner, for example uses .11 to .13 of Propeller Thrust as a 'place to start'. That difference between 11 and 13% is actually a lot of thrust to offset drag in the low end ranges of speed.
B. Contribution of Form Drag and Trim Drag to Zero Lift Parasite Drag (CDo in our discussions) and Induced Drag. The first two components of Drag may be as significant as CDo in the 200mph range.
The Drag side of the equation is crucial for setting the Free Body Equations properly to solve for Thrust = Drag along the velocity profile of entering a turn, pulling G's with ailerons, rudder and elevator forces until achieving equilibrium of highest G load, fastest turn rate and stable altitude.
My issues with Soren is that he appeared to be 'playing' with the V-n equations at the Manuever Point of Max V at Max G at Max CL. This is NOT a sustainable velocity or Lift Coefficient for a reciprocal engine powered aircraft at the ragged edge of stall and structural failure while sustaining enough energy to maintain altitude.
F-16 yes; Bf 109 (or Spit or P-51) NO. So the challenge is that once reliable data is in hand, the solution is iterative as the velocity profile slices through 'excess energy state' to 'equilibrium state' to enable final turn velocity and turn rate and bank angle.
1.) Form drag data based on AoA to see what was happening as aircraft entered a sustained turn at speeds higher than they could achieve for max turn rate for zero loss in altitude.
2.) Propeller Efficiencies (actual calcs that would be more suitable than 'assume .85') as well as different engine thrust expectations as a function of boost and HP for the respective fighters and models.
3.) Some insight to the actual contributions of LE slats on the Bf 109 in a high G bank. Whatever it is, it certainly is not the high CLmax Soren was touting, nor can one extrapolate CLmax calculated for level flight/clean stall conditions.
These factors, IMO, are necessary - at least to evaluate order of magnitude influence - to derive
A. Thrust of the engine at speeds well below Vmax - in ranges not optimized for the Propeller.
For the Exhaust contribution to THAT 'thrust system' at HPmax, Horner, for example uses .11 to .13 of Propeller Thrust as a 'place to start'. That difference between 11 and 13% is actually a lot of thrust to offset drag in the low end ranges of speed.
B. Contribution of Form Drag and Trim Drag to Zero Lift Parasite Drag (CDo in our discussions) and Induced Drag. The first two components of Drag may be as significant as CDo in the 200mph range.
The Drag side of the equation is crucial for setting the Free Body Equations properly to solve for Thrust = Drag along the velocity profile of entering a turn, pulling G's with ailerons, rudder and elevator forces until achieving equilibrium of highest G load, fastest turn rate and stable altitude.
My issues with Soren is that he appeared to be 'playing' with the V-n equations at the Manuever Point of Max V at Max G at Max CL. This is NOT a sustainable velocity or Lift Coefficient for a reciprocal engine powered aircraft at the ragged edge of stall and structural failure while sustaining enough energy to maintain altitude.
F-16 yes; Bf 109 (or Spit or P-51) NO. So the challenge is that once reliable data is in hand, the solution is iterative as the velocity profile slices through 'excess energy state' to 'equilibrium state' to enable final turn velocity and turn rate and bank angle.
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GregP
Major
Het Bill,
Your post 1013 is pretty darned well said.
I tried to come up with some performance estimates myself and ran smack dab into a general lack of data, too. Almost all of the data I have on WWII planes is not of the technical variety, and the technical data I have are very incomplete.
I've seen the estimated CL of the slatted portion of the Bf 109 wing in the past, but have yet to see any data on the much larger non-slatted portions at the same AOA and general data points. So there ARE data, but most are very incomplete and are not at the same points.
I came to the conclusion that unless you could collect the aerodynamic data for all the major WWII participant aircraft, any analysis would be so incomplete as to be a waste of time since all you can do is make calculations about small parts of a plane in very specific conditions that do not match one another.
Frustrating, to say the least.
Even here in the U.S.A., not all the manufacturers specified the data at the same points or same power and rpm conditions. That usually makes comparions a bit of of an "I say / you say" thing taht has no real answer. I have great data, such as the standard wing area, power, weight, etc., but without CL / CD / CDO and many other data points estimation is fraught with assumptions.
Wish we could find all that stuff! If we DO, I volunteer to help catalogue it and help with the analysis.
Your post 1013 is pretty darned well said.
I tried to come up with some performance estimates myself and ran smack dab into a general lack of data, too. Almost all of the data I have on WWII planes is not of the technical variety, and the technical data I have are very incomplete.
I've seen the estimated CL of the slatted portion of the Bf 109 wing in the past, but have yet to see any data on the much larger non-slatted portions at the same AOA and general data points. So there ARE data, but most are very incomplete and are not at the same points.
I came to the conclusion that unless you could collect the aerodynamic data for all the major WWII participant aircraft, any analysis would be so incomplete as to be a waste of time since all you can do is make calculations about small parts of a plane in very specific conditions that do not match one another.
Frustrating, to say the least.
Even here in the U.S.A., not all the manufacturers specified the data at the same points or same power and rpm conditions. That usually makes comparions a bit of of an "I say / you say" thing taht has no real answer. I have great data, such as the standard wing area, power, weight, etc., but without CL / CD / CDO and many other data points estimation is fraught with assumptions.
Wish we could find all that stuff! If we DO, I volunteer to help catalogue it and help with the analysis.
Sorry for not replying to your question earlier.
Part of the reason I've made such statement was to stir the pot, since I didn't agreed that D-9 was a proper answer to the Merlin Mustang and P-47 from the same era, as it was often suggested by the proponents of the D-9. So maybe I've gone a bit overboard with 'eating for breakfast', but at least Spitfire XIV should have no problems with Fw-190D-9.
Well, that differs to Clostermann's statements in his books. I'm aware that there is a lot of phantasy in his books but he knows Tempest and Spitfires and fought against D-9s and he rated the D-9 higher than any allied aircraft except the Tempest.
The Fw 190 with in Line V12s, had the potentional to be more than equal for the allied fighters. However because of the war conditions several compromises were made that crippled the final result that went in production, as D-9. The compromises were
1) request to use B4 fuel, i remind that the Fw190A used C3 for almost all its career
2) quality of Construction (due to lack of skilled technicians, lack of Materials eg rubber to seal the engine gap, demand for gast production)
3) demand for very,very easy production. This resulted in design choises that added weight. eg the demand to deliver the engine as a complete power egg added weight, which in turned requested the extention of the rear fuselage which again increased weight
4)use of engines initially intended for bombers. Thus instead of a Motor cannon had druggy nose mgs with their heavy synchronization gear
5) lack of 2 stage superchargers, delayed beyond any hope again for production purposes
6)in order not to disturb production the same wing was retained. So the result was very High wing loading . By the time they decided that enough was enough and introduced new wings for the 190 family was far too late. For the same reson other improvements were not made eg fully retractable tail Wheel, lighter 20 mm guns etc
7) request for heavy armor and sophisticated radio equipment. Things nice to have but in combination with the weak engine the performance suffered
Because of the above reasons , i would agree with Tomo Pauk ,that the average D9 was generaly inferior to the 1945 anglosaxon fighters.
However when a D13 flew against a tempest post war proved decently competitive
drgondog
Major
Basis CDo and CL for a postulated bank angle and Velocity are pretty straight forward but Thrust which is absolutely required to be accurate for modeling is suspect for the reasons I posted earlier. Ditto Drag when the airframe is at high AoA and Form Drag due to lift for the wing/body system becomes important - IMO even moreso than Trim Drag of the empennage.
