JG1_Pragr Posted February 4, 2013 Posted February 4, 2013 Am I wrong or this is the plane tested with Ju-87 screw?
Crump Posted February 4, 2013 Posted February 4, 2013 It is physically impossible to mount a Ju-87 propeller onto an FW-190. Propellers have a very limited application of engines they can be mounted too due to vibrational harmonic compatibility.
JtD Posted February 4, 2013 Posted February 4, 2013 Am I wrong or this is the plane tested with Ju-87 screw? The hub you can see at 2:43 is VDM, not Junkers VS11.
Crump Posted February 4, 2013 Posted February 4, 2013 I bet that thing had some awful vibration and was scary to fly. You can mount the propeller off a BMW801A or G series which is a common bomber engine used by Germany. I would have to look in the Ersatzteilliste to get the details but I do not think the planform (blade airfoil/shap) is the same on the A and the D2 although the hub certainly will mount.
NZTyphoon Posted February 4, 2013 Posted February 4, 2013 Thanks for that Mustang. Its clearly ex-JG54, but does anyone know how and when it was captured? By the looks of it the spinner has been damaged and is slightly off centre.
JtD Posted February 4, 2013 Posted February 4, 2013 It's said that this is Fw190A-4 (WNr.142310) force landed by Uffz.Helmut Brandt on 13th January 1943 on the ice of Lake Ladoga. He supposedly had a problem with gunfire synchronisation and shot off his propeller blades. It is thus possible that the aircraft received propeller blades of a Ju 87 from a nearby depot before being transferred to testing, but I've seen no reliable info on that. As mentioned, the video shows it with the normal VDM hub, and the propeller blades look much like VDM and nothing like VS11. So I think it is safe to say the plane was tested with the proper propeller. There is a bit of info here: http://airpages.ru/eng/ru/fw190a.shtml
Crump Posted February 5, 2013 Posted February 5, 2013 is thus possible that the aircraft received propeller blades of a Ju 87 from a nearby depot before being transferred to testing Not really, the blade shanks will not fit in an VS11 hub. It is very unlikely that they tried casting new blades on the old shanks or repairing such extensive damage. That is simply not a possibility with a propeller.
NZTyphoon Posted February 5, 2013 Posted February 5, 2013 (edited) It's said that this is Fw190A-4 (WNr.142310) force landed by Uffz.Helmut Brandt on 13th January 1943 on the ice of Lake Ladoga. He supposedly had a problem with gunfire synchronisation and shot off his propeller blades. It is thus possible that the aircraft received propeller blades of a Ju 87 from a nearby depot before being transferred to testing, but I've seen no reliable info on that. As mentioned, the video shows it with the normal VDM hub, and the propeller blades look much like VDM and nothing like VS11. So I think it is safe to say the plane was tested with the proper propeller. There is a bit of info here: http://airpages.ru/eng/ru/fw190a.shtml Cheers. By the looks of it the Russians had been able to get their hands on other 190 propellers - as you can see below even the narrow blades used by the Ju 87B-1 had a different shape to those of the 190, particularly near the roots. (Kagero 25; Junkers Ju 87 vol 1 Murawski) Same footage with English commentary plus info on some experimental Russian fighters and the Yak 9 Edited February 5, 2013 by NZTyphoon
JtD Posted February 5, 2013 Posted February 5, 2013 (edited) They wouldn't necessarily need another 190 propeller, it's possible a VDM with the same diameter would do. To my knowledge, some DB bomber engines used a 3.3m VDM prop similar to the one the BMW had. These were installed for instance in Bf 110F and G models. Edited February 6, 2013 by JtD
Crump Posted February 5, 2013 Posted February 5, 2013 VDM with the same diameter would do. It is not just diameter. It would have to be harmonically compatible as a propeller and engine combination otherwise the result is a broken crankshaft or shedding a propeller blade. Both of which are generally fatal in flight. The Soviets probably found another BMW801 compatible propeller in repairable condition. If they used a VDM DB propeller of the same diameter the results most likely would be disaster without testing the harmonics. The result of that could be a restriction in rpm or a portion of the rpm band unusable. The BMW801A/G was used on a several German bombers in use. http://www.enginehistory.org/German/BMW/BMW801.pdf
Crump Posted February 5, 2013 Posted February 5, 2013 The performance the Soviets recorded in that aircraft gives good agreement with German data. They tested it at 1.32ata @ 2700 U/min for the maximum power. The data at that power rating represents ~3.77% pessimistic from Focke Wulf manufacturing tolerances. That is easily explained by the condition of the aircraft and instrumentation error. It is not the best example of a Focke Wulf 190A4 but then as in any range, some are better and others worse than average.
JtD Posted February 5, 2013 Posted February 5, 2013 (edited) The BMW 801 powered Do 217 used a prop with a 3.9m diameter and the Ju 88 a prop with 3.7m diameter. These are clearly not suitable for use with the BMW 801 as on the Fw 190. Please stop posting misinformation. Edited February 5, 2013 by JtD
Faustnik Posted February 5, 2013 Posted February 5, 2013 Captured test results are some times questionable. This Fw190A4 Lake Ladoga test is similar as the Lerche's La5 test. I like the EB-104 test. The weights and fuel are close. http://www.degnans.com/markd/Fw190A3_EB104_Speed.gif http://www.degnans.com/markd/Fw190A3_EB104_Climb.gif The Fw190A4 Lake Ladoga has great video!!!
Crump Posted February 6, 2013 Posted February 6, 2013 (edited) Please stop posting misinformation. The propellers for the BF-110 and the FW-190 were completely different. The Governor for the BMW801 is 9-9536 and the DB-600 series used the 9-9518B. Adopting the Governor would be a technical nightmare if not impossible. The hubs are completely different with different gear ratio's. It just would not work without a complete redesign of the propeller. What they could do is take another propeller for the BMW801. Did they do this? I don't know but it is more technically feasible than adopting a Bf-110 propeller. Ju 88 a prop with 3.7m diameter <_< You should see the performance with a 3.7 Meter propeller. It was 10-20 kph slower than the serial production propeller on average. Edited February 6, 2013 by Crump
MiloMorai Posted February 6, 2013 Posted February 6, 2013 The propellers for the BF-109 and the FW-190 were completely different. The Governor for the BMW801 is 9-9536 and the DB-600 series used the 9-9518B. Adopting the Governor would be a technical nightmare if not impossible. The hubs are completely different with different gear ratio's. It just would not work without a complete redesign of the propeller. What they could do is take another propeller for the BMW801. Did they do this? I don't know but it is more technically feasible than adopting a Bf-109 propeller. Where did this Bf109 come from?
MiloMorai Posted February 6, 2013 Posted February 6, 2013 Did the Germans have a standard for prop shafts like the Americans and British did?
JG1_Pragr Posted February 6, 2013 Posted February 6, 2013 (edited) ...They tested it at 1.32ata @ 2700 U/min for the maximum power. The data at that power rating represents ~3.77% pessimistic from Focke Wulf manufacturing tolerances... I've thought the 190A-4 used the BMW801D engine with 1.42ata/2700rpm in fact. The 1.32ata was maximum of BMW801C Edited February 6, 2013 by I/JG3_Pragr
JtD Posted February 6, 2013 Posted February 6, 2013 Crump, only you would change the reduction gear, the hub, the governor and whatnotelse instead of just replacing the blades - you know, 115mm shaft diameter, same fittings, and then go on worry about the details. I wasn't aware that the Soviets set up a special task force to infiltrate Germany just to acquire a one of a kind propeller the Fw 190 was being tested with, which they then didn't mount. And what a wooden prototype prop has to do with the Ju 88 serial prop in the first place, may forever remain your secret. Likewise I don't want to know the relevance of that all considering the video clearly shows a 3.3m prop. Please stop posting misinformation. Given that it is most likely the Soviets simply used the proper propeller I have zero interest in discussing this further. Pragr, Soviet sources are inconsistent when it comes to the power settings they used for BMW 801 on the Fw 190, but 1.32ata @ 2700 rpm and 1.27ata @ 2400rpm can be found. Both power settings are for a 801C, but the A-4 as tested by the Soviets definitely had a 801D.
NZTyphoon Posted February 6, 2013 Posted February 6, 2013 Given that it is most likely the Soviets simply used the proper propeller I have zero interest in discussing this further. Pragr, Soviet sources are inconsistent when it comes to the power settings they used for BMW 801 on the Fw 190, but 1.32ata @ 2700 rpm and 1.27ata @ 2400rpm can be found. Both power settings are for a 801C, but the A-4 as tested by the Soviets definitely had a 801D. +1 There's absolutely no reason to believe that the Russians didn't go for the easiest solution and replace 190 prop blades with other 190 prop blades, or even an entire 190 propeller unit. Anything else is just pure speculation. Anyway, thanks for the video again Mustang - it would be interesting to know what happened to that particular 190.
Crump Posted February 6, 2013 Posted February 6, 2013 (edited) There's absolutely no reason to believe that the Russians didn't go for the easiest solution and replace 190 prop blades with other 190 prop blades, or even an entire 190 propeller unit. Exactly Given that it is most likely the Soviets simply used the proper propeller Exactly. I've thought the 190A-4 used the BMW801D engine with 1.42ata/2700rpm in fact. The 1.32ata was maximum of BMW801C The Russian's used 1.32ata @ 2700 U/min. I have the report and it lists the maximum power output of the engine as being 1.32 ata. It does not say why, it just list's that as the maximum. Pilots carried Betriebsdatentafel in the cockpit. The engine could have been restricted due to cylinder replacement, overhaul, or even a getting a new engine. It is prefered to use a non ashless dispersant, non-detergent, oil during the break in period while it makes metal, seats the rings, and oil consumption stabilizes. Once consumption stabilizes, the restriction is removed and the oil is changed. The pilot may have told a big lie and they bought it. Interesting thing is they speculate on the FW-190A5 development. The new fighter variant is more heavily armored and they proceed to list the F series armor. Below is an example Betreibsdatentafelfrom an FW 190: Edited February 6, 2013 by Crump
AX2 Posted February 6, 2013 Author Posted February 6, 2013 (edited) Interesting discussion. Obviously in BoS They will use Luftwaffe data. I only can get data about FW 190 A5 http://www.wwiiaircraftperformance.org/fw190/fw190a5.html About Lerche's La5 test. He mentions something about a problem with the boost of La 5 FN for lack of air intake, We could not use the Boost above 2000 meters or in climb situation. I dont understand well, can someone explain it to me? Edit Also I just read about the Luftwaffe, had captured 3 more La 5 but not FN Edited February 6, 2013 by Mustang
Crump Posted February 6, 2013 Posted February 6, 2013 Crump, only you would change the reduction gear, the hub, the governor and whatnotelse instead of just replacing the blades If the hub, governor and whatnotelse is different then the blades are most likely not useable for the system. It all kind of works together.
Crump Posted February 6, 2013 Posted February 6, 2013 (edited) He mentions something about a problem with the boost of La 5 FN for lack of air intake, We could not use the Boost above 2000 meters or in climb situation. Engines only see density altitude. If the air to too thin or moving to slowly to gain the benefits of intake RAM air, then the engine was probably unable to maintain the higher manifold pressure of emergency power. Most people only see these very limited overboost conditions in these games as "normal" performance of their favorite. Most of that data is corrected to standard conditions. Conditions were rarely standard. There are times that these highly overboosted conditions gave little or no performance improvement. There are even conditions that while engine might run fine in the overboost condition, the airplane loses performance over what it could achieve at a lower setting. Edited February 6, 2013 by Crump
Crump Posted February 8, 2013 Posted February 8, 2013 And the point of this discussion is...? Read it
FTC_Karaya Posted February 10, 2013 Posted February 10, 2013 Interesting discussion. Obviously in BoS They will use Luftwaffe data. About Lerche's La5 test. He mentions something about a problem with the boost of La 5 FN for lack of air intake, We could not use the Boost above 2000 meters or in climb situation. That sounds about correct as IRL the M82's boost was restricted to altitudes below 2000m And yes I hope they use German test data for the German aircraft... 1
Krupi Posted February 10, 2013 Posted February 10, 2013 That sounds about correct as IRL the M82's boost was restricted to altitudes below 2000m And yes I hope they use German test data for the German aircraft... Yeah, you can't trust data based on an aircraft that in most circumstances was received in a bad state.
AX2 Posted February 11, 2013 Author Posted February 11, 2013 (edited) And yes I hope they use German test data for the German aircraft... They MUST use German test data for the German aircraft. That sounds about correct as IRL the M82's boost was restricted to altitudes below 2000m You can enable the Boost for La 5 Fn at any altitudes, But above 2000 meters, Do not increase engine performance. Yeah, you can't trust data based on an aircraft that in most circumstances was received in a bad state. Yes! an example is Lerche's La5 Fn test 520 Km/H at 0 meters . Edited February 11, 2013 by Mustang
JtD Posted February 11, 2013 Posted February 11, 2013 It wasn't allowed to engage boost with the 2nd charger gear. If you did nonetheless, you would most likely damage the engine. The handbook says it's prohibited because of the risk of detonation. At high speed, the full throttle altitude of the first charger gear with WEP was at around 1750m, without WEP at around 3250m. This means you'd be getting the full benefit of WEP up to 1750m, but some benefit up to 3250m. At lower speeds these altitudes would be somewhat lower because of less ram, about 800m and 2000m at zero speed.
Crump Posted February 11, 2013 Posted February 11, 2013 Did the Germans have a standard for prop shafts like the Americans and British did? A standard propeller shaft did not exist for anybody regarding aircraft. Each propeller must meet very specific engineering requirements for the application. That is just the physics.
MiloMorai Posted February 11, 2013 Posted February 11, 2013 A standard propeller shaft did not exist for anybody regarding aircraft. Each propeller must meet very specific engineering requirements for the application. That is just the physics. Sure crump, anything you say. I guess the Brits removed the reduction case aand swapped out the prop shaft when they were testing Rotol and deHavilland props on the Merlin.
JtD Posted February 11, 2013 Posted February 11, 2013 (edited) Some hubs were interchangeable between different engines, for instance the DB 603 and the BMW 801 could use the same hub. These engines obviously used the same shaft parameters. However, others weren't and it doesn't make sense to use the same prop shaft for a 800hp and a 2000hp engine. Several adapters existed to make one hub fit several engines propeller shafts. So, yes, standards were there but there still were more than just one prop shaft. Edited February 11, 2013 by JtD
NZTyphoon Posted February 11, 2013 Posted February 11, 2013 A standard propeller shaft did not exist for anybody regarding aircraft. Each propeller must meet very specific engineering requirements for the application. That is just the physics. Except that the Hamilton Standard propeller for the P-51D and the Aeroproducts prop for the P-51K were fitted to the same propeller shaft on the V-1650-3 & 7 series, while the V-1710s on the P-39 and P-63 used the same shaft for Hamilton Standard or Aeroproducts propellers and AFAIK the R-2800s on P-47s could take Curtiss Electric or Hamilton Standard propellers on the same shaft, so yes standard propeller shafts were used.
Crump Posted February 11, 2013 Posted February 11, 2013 (edited) So, yes, standards were there but there still were more than just one prop shaft. Really guys? That is not a standard just because some parts had more than one application. For example, AN standard fitting has a 37 degree taper to an unthreaded base with NPT threads, blue is aluminum and black for steel. Propeller shafts have no such standard and while one or two designs might be used for multiple applications or more than one propeller company designs a propeller for the engine, there is no standard. doesn't make sense to use the same prop shaft for a 800hp and a 2000hp engine Right which is why they are engineered for each application. Just because the engineer says we can use this same shaft from our other design does not make it a "standard". Edited February 11, 2013 by Crump
JtD Posted February 12, 2013 Posted February 12, 2013 (edited) You know, when all the .50ies supplied to the US armed forces were Browning M2's, they became the standard. Doesn't mean there was a standard for .50ies. Same applies to prop shafts, which, as I just looked up, came from VDM and Jumo only. Jumo used them on their designs, while VDM was used for DB and BMW engines. And VDM used standardized parts just like Jumo did, they didn't reinvent in wheel for every engine. Due to this standardisation, the same prop shafts were used on several engines with several props. This is still a long way from a single type prop shaft on all aircraft, so I think the answer to MiloMorai's question would be a no. Edited February 12, 2013 by JtD
NZTyphoon Posted February 12, 2013 Posted February 12, 2013 Really guys? That is not a standard just because some parts had more than one application. For example, AN standard fitting has a 37 degree taper to an unthreaded base with NPT threads, blue is aluminum and black for steel. Propeller shafts have no such standard and while one or two designs might be used for multiple applications or more than one propeller company designs a propeller for the engine, there is no standard. Guess Crump has never heard of the SAE International standards which applied to all propeller shafts right through WW2 to the present http://standards.sae.org/as41f/ For example the R-2800: Which is why different propellers from different manufacturers could be fitted to the same shaft without having to alter anything (except, for example, the governor mechanism).
Crump Posted February 12, 2013 Posted February 12, 2013 (edited) SAE number spline is not a standard shaft, LOL. http://mech.sharif.edu/~durali/design/Shafting/details/Lecture%2020.pdf except, for example, the governor mechanism). Altering the Governor?? If you mean adopting a propeller to a governor it was not designed for, it is not going to happen. Edited February 12, 2013 by Crump
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