World War Two JET POWER
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- เผยแพร่เมื่อ 5 ต.ค. 2024
- In this video I'll explain how a jet engine works and go over the particulars of the Junkers Jumo 004 with some commentary on the BMW 003 jet engine. This video is more or less a remake of the very first video I put up on this channel with extra content and improved audio.
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"Greetings, this is Greg"
Best intro ever. 😎
Up there with "G'day, it's Chris..."
@@arvedludwig3584 I see you are a man of culture.
I dont mean to be so offtopic but does anyone know a way to get back into an instagram account?
I was dumb forgot my account password. I love any tips you can give me!
@@corbingrant7422 just click the "Forgotten your password?" text on the login screen and you'll get some password reset option.
@Corbin Grant instablaster ;)
To quote John Boyd:
“Cold air comes in the front door, hot air goes out the back door, and it goes faster, and we call that thrust.”
I’ve had the shytes for a long time with jet engine videos, (agent jayz excepted), because no one explains how fuel/air metering works and how combustors work. Don’t get me started on metal creep or fir tree attachment points.
John Boyd had a low IQ, true fact
which goes to show you that if you apply yourself your IQ doesn't have to get in your way of being smart and clever .
History is full or really stoopid and foolish geniuses,
John Boyd was simply good at what he did, it's a shame more people don't know who he was
@@scotte2815 I doubt he had a truly low IQ. He obviously had great imagination and creativity even if he didn't understand the math behind E-M. Great instincts none the less.
@@taylorc2542 I believe his IQ measured around 90, which goes to show you that IQ numbers don't always mean something.
@@scotte2815 He flew aircraft, he did NOT design and build them! If you're reasonably on the ball you don't need a high IQ to fly an aircraft. You just have to be well-trained to do it well. So, if Mr. Boyd had a lower than average IQ but better than average flight training, he could have been a very good pilot.
Designing and building a really good aircraft (and engines) requires a lot of people with very high intelligence. It's an entirely different pursuit from flying them.
The Meteor first flew with an axial engine. The Brits opted for a centrifugal engine because it lasted much longer than the early axial engines. Realize also that the Mig-15 had a centrifugal engine (of British design) and did pretty well against the F-86 with an axial engine.
A Meteor was fitted with a very early turboprop in 1945, the RR Trent to become the worlds first turboprop aircraft.
@@tristacker Sure did. Some of those testbed aircraft from the early jet/jet turbine days made good use of older airframes to develop the the-new technologies.
Wrong, The Meteor first flew with Halford H-1 engines which had a centrifugal compressor (March 1943), The Rover W.2 (Whittle) engine intended for the aircraft was at that time only producing 60% of the thrust required. A later prototype did fly with the Metrovick F.2 Axial flow engine (November 1943), but it was lost, along with the pilot when one of the engines exploded in flight (January 1944).
Norbert Riedel, the engineer who designed the starter motor for the German jet engines, actually went on to design and build motorcycles after the war.
Yes, two stroke flat twin!
Wow, thank you for that.
en.wikipedia.org/wiki/Imme_R100
@@marcconyard5024 Single cylinder
@@vicent436 Flat twin. The MZ BK350.
Since I was a kid looking in the encyclopedia and library books -- I'm 60 now -- I have never heard an explanation of why air is not simply pushed into a spiral through the compressor blades with each stage simply increasing the speed of the spirol instead of increasing the compression. Every diagram, video, and graphic I can recall has shown the entire compressor section to be turning along the axis. Until now I have never heard the term stator blades nor heard that they remain static within the compressor group. Finally everything makes sense and I don't feel like I just can't comprehend jet engines. An immense thank you to you, Greg!
Thanks, I'm here to help.
Instant upvote for not erroneously pronouncing Messerschmidt as Meshersmidt like everyone else does.
You mean all the people at Messerschmitt do at the factory in Manching Germany
@@michaelshore2300 I’m a German, I haven’t once in my life heard anyone do that. So why would they and what makes you believe they do?
tho' i think one junk-erse sneaked in.
Willie Knifesmith.
I could listen to Greg lecture all damn day on history of any kind..He'd be the kind of teacher you'd never show up late to class for..
Greg is the GOAT. Best underrated channel in youtube without doubt
I can't wait for more of the soothing dulcet tones of Greg as he educates us on the engineering of airplanes I grew up loving. My flight instructor in the mid 70's was himself a fighter pilot in the Battle of Britain- Like most from that era he was not a talker. Sadly I don't even know if he was in a Hurricane or Spitfire, I regret my shyness. He became my commander at Fulton Airbase and was a great guy and originally my chemistry teacher at my academy. He would highly approve of this. I got to be a Flight Sgt but my poor eyesight doomed my career so I quit, immigrating to NYC dec 1979 never to return to the UK. Never regretted the decision but missed the flying. My childhood dream Greg!
What did you end up doing for a living in NYC, if you dont mind me asking?
@@EinundzwanzigPanzer My first job in the US was working on Wall Street for a man who made $ 2 million a day on good days. He was both a vice police commissioner of the city and also Chairman of the NYSE Fair trading Commission. We 'scum' got a hefty (sarcastic) $ 3.35 an hour at that time and while being the 'gopher' got to go take my breakfasts, lunch with my boss and his fellow overlords at the Bull and the Bear. 11 months of that was enough but what was great was playing lead guitar for John Lennon's friend David Peel. His murder still bums me out. Now I live in Sweden because of a beautiful woman and my son! The Covid here is appallingly badly handled!
Just because you asked from Germany, my mother is German, born in Mannheim 1938 and still lives on Long Island and I talked to her just 2 hours ago. An incredible woman and I never felt all British because of her, the best person I know and my role model. Even now she is strong minded and with it. My family were anti Nazis, rightly accused of being 'friends of Jews' and persecuted for it indeed that is how I got my job on Wall Street through her connections. My uncle Helmut can be seen on a 1947 U tube video welcoming back Yehudi Menuhin to Germany which is amazing and I only saw that for the first time myself 3 months ago. My Uncle Verner was an Airplane designer who came to the US after the War and lived in Philadelphia. He and Greg would have gotten on great but he died 10 years ago. I also got my musical talent from her (she played concerts when young, Rachmaninoff, Chopin, Lizst, Bach, Mozart my favorites) while my Dad's younger Brother Bryn (Welsh father) was in the Canadian Air Force and also a Sgt which is where my initial interest in the RAF as a career path started before biology (lousy eyes) ended it. Sorry this is in English but my Swedish is much better than my German. 'Hey på dig! God Jul!' (Greetings and Merry X Mass!)
@@vladdrakul7851 with your name I would have guessed you were a phlebotomist.
@@billbolton By your rude and sad attempt at humor I would guess you are emotionally about 12?
@@vladdrakul7851 Sorry about the rude comments here. You answer someone's question politely and then idiots, turn up and just can't help themselves from being jack asses. .
Hi Greg. I believe the Ju287 was never meant as a production/service aircraft, but as a developmental type. Engine placement for jet powered bombers in future was being trialed on it, as well as the novel concept of the FSW (Forward Swept Wing) paradigm. Spatted landing gear were natural for this, especially as the plane was being glued together out of the parts of other aircraft in every way possible. And the Ju287 wasn't a "four engine bomber" as 6 engines were also trialled on it. It was a purely experimental airframe and retractable gear was a later step. Also, how many experimental and prototype planes were lost because of gear failures? A lot. By that measure, the Ju287 (a shoestring project) was the safer alternative.
Your take is entirely on target. It was a test bed for a variety of concepts, and was never intended as a combat aircraft. As an aside, it apparently had excellent handling and speed characteristics.
Excellent pick up on the landing gear.
Just like early versions of the 262 were awkward.
ISTR reading that the undercarriage used on teh 287 were taken from captured or wrecked Liberators (and presumably had spats added ad hoc).
The spatted undercarriage was also chosen to avoid dirt and stones getting sucked into the engine, that were thrown up by the wheels on grass runways. Debris coming off the tyres was caught in the spats
Still blows my mind that they were started like a Lawn Boy.
Imagine your crew are getting ready to prepare this plane for you, They’ve loaded it up with bombs and ordinance but someone left the lights on in the bloody cockpit and drained the batteries!! Oh well it looks like someones gotta go and atleast help. As the pilot of either the 262’s or arado’s you go up and start to rip the fuck out of the wire till that 10hp engine kicks on and you see the engine starting to turn and the blades spinning quicker and quicker.
Logistics... any airfield that supports bf109 and fw109 van also support me 262. No need to haul a starter around when the front is shifting fast, for airfields that means 100 miles a week sometimes.
The primary Electric Starter activated by a cockpit mounted switch... pull start was an axillary backup.
My favourite part of the BMW-003 is that it was used as the basis for a prototype turboshaft engine implemented on the panther chassis. There were 3 different versions; one which had the whole engine but with extra turbine stages to extract more power, one which used bleed air off the compressor to drive a turbine with its own combustor to drive the transmission, and one with a heat exchanger to improve efficiency.
Thank you for that video. The best report on the theme I have ever seen.
The Ju 287 V-1 was a pure low speed testbed for the forward swept wing. It was never ment to fly fast. It had almost nothing to do with the planned production version.
It was a real Frankenstein. The fuselage came from a He 177, the tailplanes from a tail turret equipped Ju 188 or 388 prototype, the main landing gear from a Ju 352 and front landing gears in their previous life had been the main landing gears of a downed B-24! It was powered by 4 Jumo 004.
The V-2 was basically the same, but with 6 BMW 003.
The incomplete V-3 and planned production aircraft had a completely different fuselage, based on Ju 288 and 388 parts and of course with fully retractable landing gears. They were planned to be powered by 6 BMWs.
When the Ju 287 V-1 was ready to be tested, there were no airworthy BMW 003 availlable. Some months later the situation changed. Now, BMW 003 were availlable, but Jumo 004 were in short supply, because every 004 was desperately needed for Me 262 and Ar 234.
The developement was continued in the USSR as the EF-131 that reused many parts from the wartime prototypes and later with the heavier EF-140, until everything was stopped in favour of domestic sowjet designs with backward swept wings.
This is the first time I've had a jet engine explained to me where I very nearly understood it! Thanks Greg!
The engine designers certainly nailed it first time,, good to hear them getting the credit they deserve.
UK designers 2 years at least ahead but not so much rush no need. Whittle proposed Fan and afterburner in 1943
@@michaelshore2300 I'm not convinced, that the only obstacle was lack of motivation. Two years ahead would be 1942, right? I'm pretty sure the Meteor would a great help in Africa and Italy, maybe even as an escort fighter for USAF.
He-178 flew in 1939, so it would quickly escalate to usual axis vs allies argument, wouldn't it?
The only constructive thing would be a Greg's video on early jet engine development.
@@urlichwichmann6456 There was no need for superior intercepted in the UK after 1940 there were sufficient piston fighters to deal with the treat. Had the Arado been more of a treat later then that would have increased the pressure. Escort ??? meteor had very short range.
.
@@michaelshore2300 please write more carefully, because I don't understand your point about Arado jet bomber. English isn't my mother tongue.
What exactly makes you think, that allies had enough interceptors beyond 1940?
Meteor F.4 could carry drop tanks, but I think you're right. Long range bombers would be too slow for the Meteor, but what about fighter bombers and short range missions?
@@urlichwichmann6456 There were little serious day light bomber operations by the Luftwaffe after 1940 and Spitfires were more than adequate to deal with what there was, as they had no escort. Late 1944 The Luftwaffe sent Arado 234 jet air craft over UK, most as reconnaissance but a few as bombers, with very small payload. Had these become a real threat, as the B17s and Lancasters were in Germany then the need for a jet interceptor would have become an issue. So there was no need for one. In Germany on the other hand there was a desperate need for something to counter the escorted B17 raids and hence a rushed Me 262 program.
The D ring 2 stroke starter like a lawn mower continues to blow me away. I think they used a starter kart normally but if they were hiding on the autobahn they used the pull starter . It was pure genius !
+Ron Lawson The little starter motor also had an electric start option.
I remember "holding" short of the runway, behind a post-war T33 with the "take off when clear" instruction. The T33 started it's takeoff roll so I waited for a bit before pulling out onto the active runway. I lined up and looked ahead to get a visual on the plane. I looked up...higher...higher...higher. I literally had to lean forward to catch a glimpse of the antique silver jet punching a hole in the sky. At that point I understood what a jet was.
Eloquently put
And the T-33 was derived from the P-80 which was actually operational in Europe during WW2 as the United States second jet fighter…
And both ran on British designed engines…
@@allangibson8494 If you wish to compare P80 with the Me262 you have to compare the April 45 version of it.
If you compare the later T33 you should compare with the 004H version with 11-stage compressor and 2-stage turbine, to deliver 17.7 kN (3,970 lbf) thrust at 6,600 rpm.
@@holgernarrog962 None of the later Ju004 engines flew during WW2 - and the Russians found them such utter dogs they replaced them in service with British Nene and Derwent derived designs within 12 months - the same Nene powering the 1944 Gloster Meteor.
@@allangibson8494 You are living in a different world
SIDE NOTE: The BMW 003 combustor looks very much like the GE90/GEnx combustor! It is a twin annular design with a bunch of small flame "cups" in a circle within a single annular chamber.
The BMW -003 family is still in service today, it was produced after the war as the ATAR 101 series.
@@fritzwrangle-clouder6033British alloys? 😂
@@sandervanderkammen9230 Hello Sandyboy, It's so funny to see you still touting that garbage, especially when you whine so much when people point out that the MiG-15 was powered by a copy of the Rolls Royce Nene.
The poor old French lumbered themselves with the BMW 018, Oestrich and more than a hundred German engineers and with almost as many French engineers and even then they had to almost completely redesign it and finally adopt British Nimonic Alloys to eventually get a viable engine in service years behind comparable British and American engines.
@@StabyMcStabsFace From Special Metals website -
"Birth of NIMONICDuring World War II, Wiggin Alloys invents NIMONIC alloys for gas turbine engines."
From Science Direct website -
"1.3 Superalloy development for aeronautical applications (1940-1960) During World War II, the Wiggins Company (UK) developed a basic alloy, Nimonic 80 (Fig. 1.1), Ni-20Cr-2Ti-1Al - up to 3Fe,1Si,1Mn - with an UTS of 1000MPa at 500 degrees C"
From 'Nickel and Its Alloys - U.S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS' -
"The series of alloys known as Nimonic alloys are nickel-chromium and nickel-chromium-cobalt base alloys specifically developed to meet strict limitations on permissible creep of vital components under given conditions of stress andtemperature. There are also available complementary casting alloys, known as Nimocast alloys, for high-temperature service. Detailed data on these alloys are given in publications by Henry Wiggin and Co. [590,591]"
From European Patent Office 'EP0097320A2 - Prechamber or swirl chamber for a combustion engine'
"The embodiment shown in FIG. 3 is particularly preferred because the inner molded body 2 is also stripped from an outer molded body 4 on its underside 10. In this case, the inner molded body 2 consists of a high-temperature alloy with the material no. 2.4969, e.g. is manufactured under the trademark Nimonic by the British company Wiggins."
From 'THE DEVELOPMENT OF DEFORMATION TEXTURES IN CALCITE ROCKS - Christopher James Spiers, BSc, ARSM.'
"2.2.2 The Nimonic Apparatus - The Nimonic apparatus and its associated control and measurement systems are described in detail by Shaw (1980). The machine is broadly similar in principle to the Heard-type apparatus but was designed for high temperature deformation work. It owes its name to the fact that the pressure vessel and pistons are fabricated from Nimonic 105 Superalloy (Henry Wiggins and Co.) which is highly resistant to creep at temperatures up to 800-900°C. "
From 'Hochtemperatur Drucksensor für Gasturbinen Monitoring und thermoakustische Anwendungen 6025B_003-611d-10.22 2022 Kistler Gruppe,'
"Nimonic ist ein eingetragenes Warenzeichen von Special Metals Wiggins Ltd."
From 'A HISTORY OF SUPERALLOY METALLURGY FOR SUPERALLOY METALLURGISTS - Chester T. Sims, General Electric Company Schenectady, New York 12345'
"In the 1929-1930 period, additions of aluminum and titanium to alloys in England, United States, and Germany created very slight amounts of y’ (N&Al), a coherent “age-hardening” cubical strengthener, in the austenite. y’, for instance, was in both the English Nimonic 80 and the German Tinidur, or A-286. "
From 'CARACTERIZACIÓN DE UNA SÜPERAIJEACION TIPO NIMONIC Ing . Luxs Zamora Rangel (ITM) Dr. Enrique Martínez Martínez '
"La primera superaleación Base-Níquel endurecible por precipitación fue la - Nimonic 80, desarrollada en Gran Bretaña en 1941."
From The Royal Society - 'LEONARD BESSEMER PFEIL 1898-1969 Elected F.R.S. 1951'
"The achievement of the Birmingham laboratory was to be the first to understand the essential requirements and the types of material, the heat treatments and the methods of manufacture that would be needed; and to develop the highly successful ‘Nimonic’ series of heat resisting alloys, with the result that the British aircraft industry was given a lead that served it well throughout the post-war period."
From I.M3 Institute of Materials, Minerals and Mining website 'Pfeil Award' -
"Dr Leonard Bessemer Pfeil whose death occurred on February 16, was a metallurgist of distinction. His research on single crystals and the scaling of iron and steel in the 1920s earned him a recognition that was further enhanced when, in 1940, a research team under his leadership introduced the first series of Nimonic alloys."
An excellent update of your original vid Greg. First time I heard of the afterburner 004! As for short life, Bob Strobel, responsible capturing ME262s, crew chiefs, designers and pilots for Watson’s Wizzers and flying them to Cherbourg for transfer to the US, Bob Strobel says on film that he ‘knows for a fact, that the 262 engine took only 30 minutes to exchange’ as opposed to two/three days for an ICE V12.
BMW 003 derivatives had a good run for many decades as Snecma ATAR in the French jets. In a long term, I’d call it the most successful WW2 jet engine. :)
That's a fair point, in post war usage the BMW derivatives did pretty well. However during the war it was all Jumo 004.
Greg's Airplanes and Automobiles oh yes, fully agreed, and sorry for being a smartass.
@@GregsAirplanesandAutomobiles
Another not so known fact is, that Daimler also did a take on building a jet engine during ww2.
They went even further and built a bypass counterrotating fan turbine jet engine.
However their designation for it would be my favorite piece of trivia, they called it *DB 007*. :D
@@mandernachluca3774 yes, the Germans never got beyond the test bed as they could overcome some technical difficulties and abandoned the project in May 1944. Metro-Vick started working on a turbo-fan engine in 1942, around the same time as the Germans, and were still working on it when the company decided to concentrate on their other activities in 1947, by which time they were producing 18kN of thrust.
@@GregsAirplanesandAutomobiles One interesting thing I found was that in 1948 the occupying allies gave Siemens in Germany permission to make a blast furnace gas fuelled gas turbine based on the Jumo 004. It used a Jumo 004 compressor, external ceramic combustion chamber, 5 stage water cooled gas turbine and ceramic turbine nozzles. They built a handful but then were given access to nimonic and didn’t need the water cooling or ceramic guide vanes.
Krupp in fact considered developing an alloy of Tinidur with twice the nickel content for the Jumo 004 but shortages meant they stuck with a relatively low nickel content.
yeah apparently 600 grams for whole engine and that was less than piston engine. but amricans didnt have such problems and their first jet engines didnt last any longer anyway. how come? they didnt even have good alloys developed?
@@jebise1126 The problem with the early jet engines was the fuel metering. Everyone got this wrong. The Jumo 004B used a centrifugal governor which was set by the pilots throttle. It could overdose if moved too quickly causing a burnout or over fuel cold flameout or underdose and flameout. The solution was to put a differential pressure sensor across the compressor to measure airflow and dose according to that with rpm secondary. This device was called the accelerator valve or beschleuniguns ventil and was scheduled to enter service in April 1945. The alloy wasn’t really the only problem. This was all understood a little late but everyone like Bosch started adapting their fuel injection systems. Also duplex nozzles that switched to a different nozzle at low flow to ensure proper vaporisation at idle and high altitude. Lack of fir tree roots on the turbines didn’t help. The thermocouples in the exhaust displayed on cockpit gauges but needed to be connected to a Proportional Derivative controller to damp out any residual temperature spikes. Needed electronics, which the Germans had. The main thing was the acceleration valve.
One important distinction between a jet and a piston engine is "what happens when the fuel is burned". In a piston engine, the fuel is burned at constant volume; pressure and temperature increase dramatically. In a jet engine, the fuel is burned at constant pressure; the volume and temperature increase. The highest pressure in a jet engine is at the output of the compressor, not in the combustion chamber- this is why flames don't (normally) come out the front.
Not inaccurate, but I think the better explanation is that jet engine sustain continuous combustion at constant pressure. Reciprocating engines on the other hand have varying pressure, volume and temperature.
Can i ask what is the significance of burning at constant volume vs constant pressure? is there any impact on performance or characteristics of the engines? Sorry if these questions seem dumb, i'm currently an aerospace student who is halfway through learning thermodynamics so i dont fully understand these processes yet.
Fuel is burned in an expanding volume. At least in my cars.
It’s worth looking at Anthony Kay’s “German Jet Engines and gas Turbines”. There was a time jet engines might have become constant volume with the compressor loading a combustion chamber and inlet and exhaust valves alternately sequencing to drive a turbine. It does work. German railways built some that could work on powdered coal in the 1920s. Hans vin Ohain even designed one at Heinkel.
In my opinion this is a significant remark because I never got the answer during the 50 years I’m interested in airplanes. I never understood how it worked : incoming air is compressed to about 7bars, you add fuel and you burn it, raising the pressure. So how come the burned air does not block the incoming fresh air from flowing in, or even flows back to the front. This topic is never explained in whatever book or video, not even in Gregg’s video. About five years ago I asked the question to someone who graduated from Aviation Design at Delft (THE reference for technical matters in our region) and he wasn’t able to give a straight answer. Worse : he was even mumbling something about venturi-effect. About a year ago, I asked the same question to a nephew of mine who was studying at the university of Leuven and after a few days he came with the answer as explained very briefly by you : the pressure in the combustion chamber doesn’t raise but is lowered, as the chamber is open at the back end. Only the rear fan gives a slight raise in pressure as it sucks energy to make the whole circus turning.
I'm a 1941 metrovick f2 man myself, developed later into the sapphire but not really during the war as us backward brits had jet engines coming out of our ears
Steady on Paul....the Metrovok was an axial flow engine, and the US has told us that we only had Whittle's engine and that they came up with axil flow.
@@superancientmariner1394 i know, having to suffice with only 9 compressor stages and a 2 stage turbine and giving more thrust than those "more advanced" German jobbies
@@paulnutter1713 Metrovick F2/2 design was given to General Electric in 1943 (on the insistence of Metrovick as the two companies had a patent sharing agreement in place). F2/4 Beryl was first ground run in Jan 1945 and passed its 100 hours run test with no major issues what so ever (try that with a German Jet Engine). Metrovick were not interested into going into aero engine production, thus the reason that the F9 project that became the Sapphire was sold to Armstrong Siddeley in 1946. This is well worth a read.
www.research.manchester.ac.uk/portal/files/54530197/FULL_TEXT.PDF
@@richardvernon317 thanks for that link Richard, you were right, very interesting
The two-stroke Riedel starter engine also has an electric start option which the pilot can operate from the cockpit. Ground crew could use the D-ring pull if necessary.
just imagine some poor mech pulling the d ring on a 777 engine lol
@@brucefelger4015 Nowadays it's a Huffer (ground-based portable air compressor) or a Buddy start, blowing high speed air into the engine to wind up the compressor/turbine spools either from a hose (Huffer) or parking another airplane in front and running up the power to use the jet exhaust or propwash before turning on the fuel and ignitors. (Seen it done with C-130s)
@@peterstickney7608 I believe another starter principle are starter cartridges (which are inserted into a special port at the engine and then fired)
@@junkers66 Yep - and there are also combustion starters, where you light off a slug of jet fuel or some volatile nasty chemical (Isopropyl Nitrate, Hydrazine), and the expanding gases spin a turbine which is geared to spin up the engine spool.
The A-12/SR-71 used "Buicks" - external carts with 2 hot-rodded big block V-8s geared together (Originally from the Buick Gran Sport, hence the name) which drove a shaft that turned the spool on the J58s.
by now I've probably watched several dozens of your videos and what strikes me most is not only your attention to detail, your usage of source material, flight data, manuals and other documents - although it's impressive on its own - but your intellectual humility. on numerous occasions I've heard you saying things like "It's only my best guess, so someone correct me if I'm wrong", or "I don't really know, so take what I say with a grain of salt", or "there are people more knowledgeable than me that tackled this problem", or - in the latest Fw 190 video - "some people have asked me questions that I'm not really qualified to answer, you'd be better to ask them to someone who really knows this stuff". this is the thing that distinguishes a regular expert from real guru: a guru knows the limitations of his knowledge and experience and he's not afraid to admit those limitations and to point people towards more knowledgeable sources instead of pretending he knows everything. it's a rare trait of character, especially in this era of knowledge- and virtue-signalling, and for this reason even more valuable, and thank you for publicly displaying this in your videos.
The technology was very sound but Germany’s lack of access to hi-temp special metals was the Jumo 004’s only real drawback.
maybe 10 hours of operation?
Billy Sol Hurok one is consequence of the other
@@DirtyMardi understood
Yes, 10 hours service due to poor metals!
how you explain 20 hour life span of engine on P80? cant be lack of such materials.
I just learned how a turbofan engine works. Thanks Greg, I had no idea that there was bypass air thrust.
Thanks Gregg your research is astounding, we are never too old to learn . I had no idea the Jumo's jet engine s were cheaper to manufacture.
Junkers Jumo 004 was a good design which was held back because the Germans couldn't get enough temp resistant metals for the turbine in the hot part of the engine. These metals in short supply included nickel and chromium. So they had to make the turbine out of steel. This made it prone to heat failure. Pilots could only advance the throttles slowly, had to watch the temp carefully, etc. This explains the short life of the Jumo 004 between overhauls.
Yes, that's how I understood it as well.
Dr Franz had the bench test versions made out of appropriate alloys running well, then the whole development program was held up for a year finding a way to make them out of aluminium and mild steel - not ideal but available.
@@tsegulin The recently built Me 262 replicas do NOT fly with original Jumo engines. They fly with modern ( safe ) engines. I don't think an Me 262 with original engines could be rated safe for flight.
@@petenick7829 Agreed and I didn't mean to suggest they did.
What I meant was that (as I understand it) in the early 1940s the original 004-009A engines were developed using appropriate high temperature alloys which in the event were not available for mass production of the 004-009B engines, which had to be re-engineered to be constructed from aluminium and mild steel; a process that held up operational service of these engines for a year and led to a powerful engine that nevertheless required delicate handling of the throttles and had a short service life.
@@tsegulin Agree. Jumo 004 with proper heat resistant metals was a good engine.
Cant believe it another Vid, many thx and merry chrismas btw
I had watched the original video a few times, and I just watched this one twice. So much great information and insight. I learn something every time I watch one of your videos...even the tenth time! Thanks as always Greg for the terrific work. Outstanding.
*Sees video*
I will just check what he is talking about, will watch the rest later.
*24 min later*
Damn it!
Same.
Thanks for the work you put into these Greg.
Greg thank you for doing what you do right now. Its rough for me right now and you are very soothing
Steve, I hope you are doing OK, just for you I'll try and get another video up in the next few days.
They incentive for jetengines which are 1/3 of cost and can burn any fuel grade makes perfect sense for germanys situation.
You gave a very good simple explanation of turbine mechanics. It takes a lot of education to really understand them.
This is an awesome channel. Thanks Greg. I wonder if you would do an episode on how cannons fire through the spinner ? I have always pondered that. You make easily understood programs for people that have at least some engineering curiosity and desire to learn. I'm liking it. Thanks and Happy Holidays to you and yours.
I go over that in one of the two inverted V-12 videos.
Greg, thank‘s for posting this to allow us to retrace all the theory concerning aviation and engines thereof.
Please continue such !
Sadly some Fnglish are not so cool !
I think the ME262 has the most beautiful & classic lines of just about any aircraft.
I completely agree, the 262 two seater night fighter even more so, like a shark!
I strongly disagree :D Those two engine pods under the wings look absolutely stupid IMO.
@@XseuguhX what is your address?
100. %
@@XseuguhX Compared to just about any aircraft of the same period the Me262 is in a totally different league.
It had an incredibly advanced design with its swept wing and tail.
The under wing engines reduce maintenance times, improve wing strength and improve the survival rate of a damaged aircraft.
When you compare it to US first generation jets like the P-80 Shooting Star it's miles ahead.
So much thrust, more than you knew, a great engine. Amazing.
Love your videos Greg, it's really nice to hear you thoughts on all these topic, seeing the bigger picture based on facts. Please continue making videos. Thanks and have a nice day!
23:20 that airplane was a test bed made from several other airplane parts, most obviously the fuselage being taken from a he 177. The final model was to have landing gear.
Awesome video!
I think a video on centrifugal flow engines would be interesting, especially since it’s not all that common, or a pulse jet and how that works, but anyone can watch this and understand a jet engine despite their experience, and that’s tough to do
Gifted after another gift. Thanks Greg for your kind contribution!
Two videos within the month! Christmas came early!
Fantastic and informative as always Greg.
lol this is so much better than TOP 5 AIRCRAAAFT OF WORLD WAR 2 NUMBER 4 WILL SUPRIZEEE YOUUUUU
When a girl asks me what is beauty, i show her a photo of a 262
I don't think anything can compare to the beauty of a mig 29, but you can not say that to a girl. So a 262 it is :D
@@gearloose703 The SU-27 compares very favourably in the looks department, I think.
Just like the bird it’s named after...the swallow is a stand out among birds in much the same way...very well chosen name
I’m a b1b man. I like those curves. And a big touckus
@Christian Winkler: you may have intended this as a joke, but I've actually taught my wife to agree with it. we've been married for a couple of years now and the four most beloved things in our lives are each others, our two sons and the Me 262 :)
Another annular combustion engine is the vickers f2 which made its first run in 1941, and its later variants paved the way for turbofan engines on planes like the 747
They couldn't make it work, a few test flights was about all it every did.
@@GregsAirplanesandAutomobiles i see, looks like they only got 3 hours of flight time from the meteor with the f2
My Dad’s an engineer and a pilot. He and I love these videos. High quality and well produced. Merry Christmas.
The _canular_ combustion chamber configuration is a contraction of the portmanteau word _can-annular,_ and it was referred to by this word for at least a decade.
I commented under another video about the Me-262 and its jet engine, about the matter of an absolute goldmine of information about this engine in a post-WW2 Allied military technical report, designated _Top Secret_ (but obviously now declassified). The only copy I have been ever able to locate is at the aviation stacks of the Engineering Library at Stanford University.
To read it is to become even more impressed by not only its advanced engineering, but its viable infrastructure, being (relatively) easy maintenance, deployment, and integrated semi-automated control systems. It truly was a fully realized engineering marvel, especially when considering the exigencies of wartime production and fielding.
I suggest you obtain a copy of "German Jet Engine and Gas Turbine Development 1930-1945', though it is now exorbitantly expensive. On page 92, there is an extract from a Power Jets report on the 109-004B-1 engine. They were singularly unimpressed. I will quote just one line: "For general future design of gas turbine engines, there does not seem much to be learned from this engine."
the most amazing channel on youtube! thanks for your work its great
Just found your ACMI vids. Legacy airline pilot here, luv your stuff. Makes me want to get back into the old Navy books!
Hello Greg, the Picture of the Ju 287 only shows a kind oft mule. Junkers built it as a proof of concept for the forward swept wing. They took the end of an Ju 188 and the nose of an Heinkel He 277 (when i remember it correctly) and other stuff, that was lying around, to get it in the air. So no retractable landing gear. As Ef 131 it was later developt completely by Junkers Engineers in the USSR.
The retractable one was the Ju87 V3, which was a very different plane, it had 6 engines and mostly existed on the drawing board.
Ah yes... I see the forward swept wing. Thx. I'll look it up
Junker Ju-287 V-1 actually has a fixed undercarriage with a nose wheel taken from a crashed B-24 purely to speed development and act as a low speed test bed for the forward swept wing. production aircraft would have had retractable undercarriage. The Ju-287 V-1 was Jumo 004 powered but more thrust was required therefore 6 BMW 003 were to have been used.
It's amazing that the Germans were able to even get this plane from production to actually making a few of them and putting them into combat under the conditions Germany was dealing with at the time. A country that was being bombed night and day and still getting advanced projects off the drawing board is really impressive.
"Amazing" = Hyperbole. "Impressive" = Hyperbole. No it wasn't. They put out a few airplanes, what they could under the circumstances, and that is the end of the discussion. The allies were not bombing every inch of Germany. The Germans built what they could manage under the circumstances...it was no herculean feat. On the other hand, American production was an incredible (not hyperbole) feat...quality, quantity, and technological superiority almost across the board except for the minor exceptions of jet engines and late war submarines in a very short period of time...it was unparalleled in human history for a nation to grow into such sustained power so quickly.
@@hoodoo2001 And yet the Soviets produced the largest number of one type with the Brits producing the second most. The Soviets produced the most armour and best armour of the war. In short US production wasn't really anything that incredible given it's safety from bombing and fact resources didn't need to travel over oceans.
Germany actually built a lot of aircraft outside Germany which helped. Example of that was the Me 262 which was built in Czechoslovakia. This factory survived intact, post war it was hoped orders for the type could be secured from international buyers, about 15 aircraft were built and put into service in the Czechoslovakian airforce. By 1950 half the fleet had been lost in crashed and accidents and with absolutely no interest the type was taken out of service. This was the only 262 service in the post war ere even with some 1400 examples being produced during the war. A Be109 production line was also built there and produced post war to a much greater success.
Great video as always!
Good to know I'm not the only one that gets the Military Aviation History and Militairy History Visualized channels mixed up..
Another great video. Over in Britain, Frank Whittle took out a patent for the jet engine in 1928, but because he was serving in the RAF, the government claimed ownership of the patent and then declined to fund the development of an engine. Whittle always maintained that he could have developed a working jet by 1937, and a turbofan by 1939.
Maybe he could have.
1939 was indeed the year for the first jet engine propelled airframe: Heinkel HE 178 made the first jet flight in September of 1939 in Rostock, germany.
Frank Whittle did not patent the turbojet engine, Maxime Guillaume patented the turbojet aircraft engine in 1921... when a 14 year old Frankie was still wearing short pants.
@@sandervanderkammen9230 ha haaa
@@sandervanderkammen9230 Did he ever build and test his 'engine' or was his patent for a conceptual engine? If the latter you could argue that the first such engine designer was whoever designed of a rotary fan or even the windmill.
The original German engines were based on Whittle's engine patent with developments which he had also planned but was thwarted from implementing by weak government in Britain which was appeasing Hitler.
Rather than the full backing for the development of the engine given by the German Government Whittle was allowed to develop his invention in 'spare time' around this RAF duties.
The axial flow turbojet, a design Whittle deliberately avoided producing during WW2 because of the exact problems that the 003 and 004 suffered.
No.
@@GregsAirplanesandAutomobiles Go read Whittles book
The JU 287 V 1 was a testbed for the negative swept wing.The fuselage was from a HE 177 .The production model would have looked like a JU 288 with a single vertical fin.
I like your channel very much,always well done. (YT seems to have the same opinion,this video was interrupted eight times by commercials. :-))
The Arado Ar 234 C version had four of the BMW 003 jet engines, but only a few were delivered before the end of the war.
"Confusion... even afflicts Wikipedia editors." Get used to it.
Lots of fascinating stories from the early jet era: breakthroughs, shortcomings, ingenuity, oddities, and missteps. The sorts of things an aircraft history researcher on TH-cam could have a field day with.
The Ju 287 was planned to have a retractable landing gear, they just lacked the ressources to built it for the prototype since it was a sideproject noone was sure if it even would ever fly. So they went with a fixed one since that was still better than none. It was a real Frankenstein-plane, fuselage and cockpit from various Junkers planes, engines from BMW and the Gear from some B-24s that were shot down.
Junkers was siezed by the Nazi's in the thirties, who force Dr. Junkers out by expropriating his holdings and placing him under house arrest. After this Junkers Flugzeug and Mororenweke AG did what ever the government told them to.
As far as I know, Germany ran short on steel hardeners at the end of the war. Like Tungsten, Molybdenum or Vanadium. So they had to take "normal steel" for this engines. As a consequence the engines were "done" after only 25 operational hours, because the normal steel couldn't take the heat for a lengthy period of time.
The Jumo 004b Orkan engines were made with high temperature, heat resistant *stainless steel*
Krupp P-198 Chomadur is still used in jet and gas turbine production.
The Jumo 004b Orkan engines met or exceeded the RLMs 100 hours PFTR reliability standards for acceptance into Luftwaffe service.
This is the exact same 100 hour PFTR standards for the RAF and USAAF during WW2.
Another fantastic in depth video. I could sit and listen to these all day every day.
Thank so much for all the time and effort you put in to these. Should have your own tv show.
Well, with over 80 videos, you could literally watch them all day and still have plenty left for the next day. Thanks for your kind words.
@@GregsAirplanesandAutomobiles I have been...so much info I watch them at least twice 👍
Wow, thanks, I'm trying to get the next one done before Christmas, but it's not looking good for that time table, still it shouldn't be too long.
@@GregsAirplanesandAutomobiles Hey Greg...I’m the one thanking you!
I love US muscle cars & ww2 fighters so you tick both boxes 📦 I read/collect a lot of ww2 books mainly on the air war.
Thanks so much for educating me better on stuff and especially on the P47 lack of range ....or not so.
The mustang grabs the headlines just like the Spitfire over the Hurricane in the B of B.
I’m a keen follower of Blakeslee’s 4th FG and Zemke’s 56th FG so got divided loyalties with both US fighters 🤷🏽♂️
Absolutely yes, the best WWII Jet engine.❤️
On the 287, I have a hunch the fixed gear was just put on the prototypes to test the concept of the plane, before going to the trouble of the complication and expense of installing retractable gear? Just a thought Greg.
That's correct.
Thanks God Greg continues !
Your last sentence says it all. Axial , swept wings. Sabre was next. Active british tail vs tailerons . (Bottle shaped fuselage was really the only missing link) , seems so obvious in retrospect.
Really nice. I'm writing this an hour before it premieres, hoping it will cover the 003D variant. Thanks a lot, Greg.
Btw everytime I read "BMW 003", I have to grin, because I remember some slavaboo armchair general, with a huge following, writing that the Germans were too stupid to design jet engines. Which is comedic because the Soviets were unable to design proper jet engines for many years after the war and had to use the BMW 003s in their MiG-9s. Even the MiG-15 had to use foreign engines(the Nenes) which are not even axial flow.
That's exactly right, few people realize that the original Mig 9 ran with a BMW 003. I do talk about the 003 in this episode, but not too much.
I had something similar with a britainaboo he sayed the german jet engines where trash compared to british ones and no one uses the design of old german jet engines anymore and only uses the design of british axial flow prototypes lool
why deidn't you include comparison with the Wittle engine? Great presentation as always.
There is on 262 in my local museum. What a sexy beast it is.
The reports I have read from German and Allied pilots who flew the He-162 Volksjager said it was a very good aircraft. While not as fast as the Me-262 it was a very capable aircraft with good manuverability and agility. British test pilot Eric Brown said it had very light and balanced controls.
The problem was it was intended to be flown by inexperienced pilots with a minimum of training. Little to no experience in a aircraft of any type is not a good combination. Experienced pilots familiar with high performance aircraft had little problem with the Volksjager and actually liked it.
Most of the problems were due to the low quality jet engines and the glue used to build the wooden airframe. The original glue intended for use was bombed by the RAF and the replacement glue was later found to be acidic and dissolved the wood leading to structural failure.
The HE-162 was also one of the first aircraft to use a ejector seat to push the pilot clear of the jet engine right behind him.
And i believe in one of the ejector seat uses the pilot got squished...
It was also the do 335 that used an ejection seat first
@@APFS-DS HE-219 had them first!!
Do you see Hollywood? This is how you make a proper remake.
Whittle, BMW 003 and the Jumo 004 all used firtree-style turbine blade attachment points which are still in use today. I could never find who developed it first
So in 1959 the firtree turbine attachment was patented. US3045968A - Fir tree blade mount - when clearly the 004 used them in 1940
@Henry J. Totally agree. Even then, the first mention of this type of attachment is from 1930s Whittle design. What would be interesting to know is if the Germans independently developed it, or copied it
Nice, but please leave the captions up three times longer.
That's the default setting, but OK, I'll do that.
As usual, a great video. Thanks. I missed the Metrovick F2 etc./Beryl, which was a comparable British turbojet from the first half of the 40s.
My standard for comparison is operational engines that saw combat in WW2.
That was a great video, you explained this way better then my college lecturer
The history is so interesting, especially the history of the engineers like Dr Franz. Awesome!!
Nice one! And thanks for the mention!
Greetings Greg and Adam here with another educational video😁🙌🏻
@@SuperFronky Haha!
Hey Greg I have never felt the need to make a request of you but I just watched a short documentary on the fastest piston engined fighter of WW II, the Dornier Do. 335. I thought of you as you are so good at describing, various forms of drag, engine configuration. basic design shape (2 props with only one facing); If anyone could explain this brilliant exception to the usual you could. I think it would be fascinating for others adn hopefully you too though I do imagine the research would be very taxing. Nevertheless it makes a fascinating comparison to other fast aircraft of that time, whether the P 51, the P 47, the FW D's +, later Spitfires or the Mosquito.
You are not the only one to make that request. I haven't done it because based on my Me 163 series lack of popularity (compared to videos I make about 190s, 109s, etc) it seems that people are not interested in watching videos about the later war super planes.
@@GregsAirplanesandAutomobiles I am really surprised that more are not interested in these amazing planes like the Me 163 etc but I do understand and respect your decision as it is of course important for you to maintain your audience numbers. Still it would have been a very interesting analysis for the reasons I already mentioned. I cannot imagine anyone coming near to your explanations of how and why this amazing unique piston engine plane actually worked so well! I imagine you too are disappointed in that as it would be a little different than the usual for you too. I will go check out the ME 163 as I AM interested in that as well. In the few years (3) when I was in the RAF our base (Fulton, near Bristol UK) used the also unique Harriers (late 70's) and they too were 'different' in a fascinating way as well! I love 'freaks' that fly!
I probably will make a video on the 335, it's just not a priority.
@@GregsAirplanesandAutomobiles I perfectly understand and respect your point Greg. Whatever you do it is going to be great, like all your videos have been and if you do one on the Dornier I will just be extra happy! Have a good New Year Greg. I can't wait until the next one!
Totally excellent! Thank you very much indeed. Stay safe, merry Christmas, and a happy and healthy New Year!
After WW2, Avia in Czechoslovakia manufactured some Jumo 004s and a few Me-262s. I cannot remember where I read it but I think they only managed 60 TBO hours from the 004s they built. I would be curious to hear any figures on the Soviet-manufactured Jumo and BMW turbines and what TBO hours those had, if any documentation even exists for them.
Back in the late 1980s, as the Iron Curtain started rusting through, I was part of an effort to obtain and restore to flight one of the 2 or 3 (It's hard to tell) Avia-built 262s. While we had fiarly good records on the airframes, we had no data on the engines. From the comments we got from the Czech Techs, a 60 hour TBO would have been very, very unlikely.
We were going to use GE CJ610s/J85s - the same engine as an early Learjet. (And the engine chosen for the modern builds), It had the same mass flow as the Jumo 004, would fit in the nacelle contours, and could be placed to keep the CG in the right spot. With 1,000# more thrust per engine than the 004, things could get tricky. I calculated Blue Line (Minimum Safe Single Engine Speed) as 230 MPH at full power.
@@peterstickney7608 The 610s have worked out well in the new-build Me-262s. They did their homework with the power settings and put a reference card for the pilot and stops on the throttle handles for the safe settings. As far as I know Avia only made about a dozen of the S-92 jets and only two survive in museums. The Czechs were attempting to build an export fighter but the Me-262 was already outclassed and the only customer was Egypt. Avia scrapped the tooling and took a contract to build newer aircraft. Egypt had three of the Avia Me-262s and I wonder what happened to them.
A good history of the Jumo 004, and an overview of how jets work in general - Thanks for mentioning the Speed/Power relationship - it's vital, and the converse situation for propeller powerplants must be stressed - at low speeds, a propeller has much more thrust available for takeoff, acceleration and climb - the crossover point is, (discounting transonic effects on the propeller), 375 mph - below that, 1 HP is producing more than 1 lbf of thrust, and 1 lbf of thrust is less than 1 HP. This is why, during the Allied counter-jet campaign, the Allies' piston powered fighters put such an effort into engaging jets near their airfields, where the jet's lesser available thrust (Available thrust is thrust-drag) at low speed (relative to to propellers) meant that the jets were at a severe disadvantage.
A bit of context, though - in terms of jet engine technology (as opposed to jet engines in combat), the US. and UK were not behind the Germans, not did the German efforts have any influence. Axial flow compressors were not a German innovation - in the US, the Westinghouse axial flow J30 (contracted for in 1940), GE's axial flow TG100 (T-31) turboprop and TG-180 (J35) engines were running in early 1944, along with the centrifugal compressor I-40 (J33), both the J33 and J35 demonstrating twice the thrust, better fuel consumption, and longer life as prototypes than the production Jumo 004. .By Mid-1944 production of the Whittle derived J31 was just about completed. In the UK, Armstrong Siddely had run its ASX axial in April 1943, producing about 1,000 lbf of thrust more than the Jumo 004 (but not considered for production), The axial flow Metrovik F2 was the powerplant for the fist flight of the Meteor. The centrifugal Rolls Welland was in full production, and Rolls had gotten wind of the J33 and J35, so they launched the effort that became the Nene and the Derwent.
All were running before anyone other than the Germans had seen a Jumo 004 or BMW 003. Jet engines were like RADAR - the Top Secret that everybody know about, and hoped that everybody else didn't know about. That said, it's fair to say that in terms of jet engine technology, there's a fair case to be made that the Allies were leading in mid-1944 - they weren't operating under the same pressures to get jets into combat. That doesn't diminish the accomplishments of the Germans. Getting any jet into combat in 1944 was a game-changer. As you point out, Greg, since the jet's peak combat performance come at the high end of the flight envelope, and the prop's peak combat performance (acceleration, climb) at the low end, they operate in an entirely different world.
The Jumo 004 had other problems than metallurgy. The bearing and lubrication technology also contributed to the short life of the powerplants (Basically, 5 hours before rebuild, 3 or 4 rebuilds, then toss it) - In order to keep an Me 262 in the air required 4 engine sets per airplane - 1 on the wings, one in transit to the rebuild shop, one set in the shop, and one set in transit from the shop to the airplane, all subject to interdiction from the roaming Allied fighter-bombers.
It's amazing that the get as many airplanes into the air as they did - the max number of Me 262s in the air was 55, in mid-April 1945.
It also has to be noted that they compressor and turbine aerodnamics weren't good - efficiencies were low, pressure rise per stage was marginal, and they were very susceptible to compressor stall. (Which would pretty much instantly slag the turbine buckets.)
There were many ways to flame out an engine in those days, before capable fuel controls were developed. Fast throttle movements, either opening or closing, could blow out the combustor (Like turning the valve on a gas stove), disturbed airflow, even from yawing the airplane, or, potentially, an over-enthusiastic negative G application could all trigger a flameout.
To conclude - din't minimize the BMW teams efforts. the French SNECMA Atars are all direct descendants of the BMW 003. The BMW team moved to France and continued working.
Peter its good to see someone who knows the facts.
i was gonna request a remaster of the Jumo 004 video but thought Nah the FW190 is more important
That first flight of the 262 must have been breath taking. 🙂
Not really, heinkel 280 and 162 flew before it both with jet engines.
And today we have hobbiest engine builders making their own axial flow minature engines. Along with the ones building centrifugal flow engines out of turbo chargers.
Too bad Lockheed's axial flow engine didn't quite work
Building centrifugal flow engines out of turbo chargers? GE's experience building turbochargers gave it a head start in building its first jet engines.
@@fafner1 I know. That's why they got tasked by the Air Corps to build the first copies of Whittle's design. Although Lockheed was working on an axial flow in 1941 that was initially designed by Nathan Price who also developed a steam powered turboprop aircraft engine that was test flown in 1934 to 36.
It's not that the potential of jets wasn't understood in the US. I think it was more a matter of materials science and aerodynamics. If the money that the Air Corps had poured into the hyper engine program had been devoted to early jet research they would have been better off. Woulda, should, coulda
Great but some remarks , the Ju 287 va wth fixed undercarriage was only a mock-up not even a prototype the airframe was from the He 177 . It was to simply test the forward swept wing . and their engine was not 4 BM 003 but 4 Jumo . The other 003 aircraft was the AR 234 C .
Individual cans did share sources of ignition through connecting tubes
Yep. Thanks for the run-through. Centrifugal next?
Oh, I guess the issue with the Junkers bomber was testing the wing. Brave folks in those pre-computer days. You’ll find at least part of that fixed LG was comprised of B-24 parts. Great stuff!
Merry Christmas! 👍
The computer in those days was a bunch of mainly pretty female maths graduates who ran iterative spread sheet like numerical solutions. They were very good and excellent marriage material. There were a few punch card computers around. This goes back to the need to calculate nautical navigational almanacs and ephemera for celestial navigation. It’s why lady Ada Lovelace was involved in working with Charles Babbage on his analytic difference engine. Lofting a wing, flutter all done this way. Men used to do this but it was expensive to find men who would do the accurate work.
Ju-287, as on the photo, was not meant as a real bomber but as a "proof of concept" for a bomber with forward swept wings. Actually it was hastily put together with parts of different aircraft. Both of the nose wheels came from downed B-24 Liberators....It also has quite an interesting history. They swept the wings forward in order to increase flight speed more towards the speed of sound.
That last sentence is not true.
A. It had a very low LE sweep angle of about 15 deg. This is not enough to significantly delay shockwave formation (this depends on the cosine of the angle, which at 15 means only 3% increase in speed.
B. Without composite materials, it is not possible to achieve a forward sweep enough to gain meaningful aerodynamic benefits, because forward swept wings suffer from aeroelastic divergence.
This small forward sweep was to move the wing box rearwards, so that the bomb bay could be placed at the center of gravity and so a large payload could be carried and dropped with no trim drag penalty. This is mentioned in this video on the X-29: th-cam.com/video/LOmvrk3LPGc/w-d-xo.html, as well as in other places, such as Raymer's book: "aircraft design: a conceptual approach".
@@ASJC27 Hello ASJC27, They did it exactly for this reason! :-)
Pre cursing wind tunnel tests suggested exactly this.
The fact that the carry-through structure is behind the bomb bay might be positive for a bomber, but It was planned as a smaller reconnaissance aircraft at first.
Maybe one can say it was a demonstrator that was designed closely towards a serial aircraft. All in a hurry, as 1944 everyone knew the war wasn´t lasting forever anymore.
Aerodynamically, forward sweep has many positive aspects for controllability, and the boundary layer of the wing can´t move outwards (and render control surfaces useless) like on traditionally swept wings.
Furthermore, as Raymer states a forward sweep Angle of -22° leads to an elliptical lift distribution for a rectangular wing (less drag->more speed-> reconnaissance).
The Ju 287 features ca. -20° sweep.And
Positive flutter coupling is the main problem of this design.
They wanted to counter that with the placement of the engines and later with wingtip tanks, as you can see on Ju 287 V3 that was rebuilt/completed after the war as OKB-1 EF 131 and EF 140 in Dessau and in Russia.
But not having stiff enough materials in the Soviet Union lead to the cancelation after EF 140.
en.wikipedia.org/wiki/OKB-1_EF_131
en.wikipedia.org/wiki/OKB-1_140
As far as I know, the Ju 287 with fixed landing gear was just to test the ability to fly. By the way, also the fuselage wasn't from Junkers, it was from a Heinkel 177...
German for onion:
ZWIEBEL
pronounced like "tsveeble"
Richtig
Not in my part tsweeble
@@michaelshore2300 Your part.....of germany.?
I'm curious now...
@@olivergiles6731 Bavaria it is Sweeble and VW is Fou Wee Voiks WAAgen
@@michaelshore2300 Des hob i ma fei glei denkt dass'd a Boar bist! 😅
Basst scho...
Great work Greg, very interesting, technical and clear, excellent stuff, thanks. Greetings from the UK.
Wow double vids by Greg!
Merry Christmas, Greg,and thank you for all the great content.I love Ww2 aircraft,(who doesn't?),and I reckon I've read all I can about them,but I have learned a great deal more from watching this channel.Happy new year,my resolution,water/methenol injection for my car.
Really terrific video, German WW2 jets were the best. It's amazing how advance they were.
Oh yeah. Built of tin cans (mild steel) by hungry slaves. Great engine.
Hey would’ve been the best if they had the alloys they needed then they would basically surpassed the british engines maybe in reliability or atleast be as reliable
@@startingbark0356 ~ Germans didn't have enough fuel, materials and men to run the war, it was a war attrition they could win.
Great to see the channel growing! It seems to have doubled in subs over the course of the last few months. Closing in fast on 100K!!
Thank you Greg, for all the great videos!
About Ju-287 - it was on "proof-of-concept" phase - they cared mostly about the performance of the negatively angled wings, secondly for the powering by jet engines. It was an expedient experimental design, using parts that were available: the landing gear comes from B-24 Liberators, the fuselage comes from He-177; they used the ones that were available and that would show similar aerodynamic characteristics to the final design; the gear was simply the most robust they had. The production machine would have nothing to do with this build up, except for the wings, and maybe engines.
About Jumo`s short service life and Service life/life expectancy of Fighterplanes,
i have only a Quote from a Bf109 Book(Flugzeuge die Geschichte machten Bf109) :
"The service life of a Bf 109 was reduced between 1941 and 1942 from 11.3 months or 115 flight hours to 6 months or 65 flight hours and this development continued in 1944/45."