It's been sad to see Hollywood ignore the Wernher Von Braun story and do their best to edit his efforts in every way possible. I have never understood why so many people want to ignore that the V2 / A4 is a direct relative to the Saturn 5 moon rocket. Anyway that injector would make for a very cool shower nozzle and bathroom novelty item.
American don't want to to highlight the contribution of German scientists. Even these days American and British are competing with Germany. They are making every effort to show the German low.
@@Sk_max-k3m Not really, USA actually appointed Von Braun to NASA centers first director 1960 and held the position in 10year until 1970. Perhaps todays politically correct democrat-USA trying hide and covers up its the past. Democrats favorite president JFK was a friend of Wernher Von Braun, who was the first director of the NASA Center bearing JKFs name, the Kennedy Space Center. Von Braun did so much for his new country and americans today should be thankful to him.
Wernher von Braun was of questionable moral character, like many German intellectuals of the time, opportunitistically playing along with Nazi ideology, despite knowing that it was bullshit. Having thousands of people toil and die in factories and forced labor camps to produce his rockets. Yes, he knew what the SS was up to, in full. Could you praise his engineering genius, pioneering spirit, and dedication to manned spaceflight, without putting him on a pedestal? Of course you could. But even if Hollywood likes to pretend to favor "flawed heros", in reality, something like that is way to nuanced for the entertainment industry. They prefer to treat their audience like idiots who can only ever deal with black and white morality. And to be fair, I can see where they are coming from, given how prone people are to knee jerk reactions.
@@gesamtszenario Didn't the U.S. imprison more people in labor camps than were ever used in the V2 project? And the British government was doing a Bolshevik style farm collectivisation through the war ag department, including killing farmers that refused to cooperate. Plus the explicit war crime of the dehousing bombing campaign, bombing women and children in their houses in working class districts of Germany. The targeting of civilians is a war crime. You aren't one to be lecturing on morals.
I personally would beg to differ on one point. The switch from steel to brass would have been motivated by tooling life considerations. These nozzles would have been made on an automatic lathe and switching materials from steel to an easily machined material like leaded brass or leaded bronze gunmetal would enable an automatic lathe to double or tripple its nozzles made per day output. This is because the machine can be run faster with less time lost in sharpening and reseting tools and in replacing broken tools. This type of automatic lathe is cam operated and can make a nozzle like this in less than a minute. They are rarely used now because computer controlled lathes are used instead - unless huge numbers of identical components are required, like for instance the small brass screws for plugs and sockets are still made on cam operated automatic lathes.
There is no absolute need of an automatic cam lathe to make those injectors. A revolving turret lathe would be slower but give finished parts with threading done. Of course, using brass or bronze instead of steel is less punishing for tools, but it is also more difficult to find in wartime contingency. If you read the 4year old comment of Douglas Abbott, you can also consider that form tools save a lot of machining time and efforts. In this case, saving on sharpening is actually valuable. But look closely at the multi-jet nozzle ant you will see that it is hollow and the back side shows a small recess indicating it is probably a two part assembly to form an inner chamber for the whirlpool to form and spread the liquid on all holes and not only the central one.
This was one of the best videos that I have ever seen on YT. It was too the point and very efficiently done. Good job. Greetings from Apache Junction, Arizona.
Makes it pretty obvious why the US military, when they had their engineers look at the plant, decided not to only grab the stuff, but grab the folks who designed it. That was as good as engineering got in the 40s.
@@dirtbikerswe1979 Actually, the Small Hats do most of the stealing, then they sell it to China. At least one Small Hat went to prison for it; in that case, it was military science technology.
It is mentioned at about 13min into the video that you can see the lines from the lathe work on the nozzle. Strictly speaking they must a have used a form tool to make the outside shape of the nozzle. This is revealed by the fact that the machining lines are concenctric rather than spiral. Spiral lines lines are produced by a single point lathe toole and concentric lines are produced from a form tool imposing a shape in the metal. I know it seems a small useless point but I think it is best to be accurate about these things.
Hi Douglas - thanks for that comment - it's not useless at all. Far from it, I spend much time explaining that there are no mind-bendingly complex ideas in engineering - alone they are always simple, and easily comprehended but there are many compounded in layers and all very particular. Thanks for highlighting that 'particular'. KR RJD A&NTV
@@Spikejones5001 Actually, I would think they would have used a 'Swiss Lathe" to make them, the same tool used to make the components of Swiss watches. The Germans manufactured these automatic lathes used in Swiss watch factories, programmed by cams. Those lathes were unique in being able to perform a number of simultaneous operations at the same time, and very quickly.
At 13:30 About the steel vs brass nozzles. I wonder if corrosion was really an issue. After all, they are not re-usable. And I assume that they are used as fast as they are produced. Maybe they are just faster/easier to produce from brass stock.
Very cool video. The sight of one of those single injectors in hand gives one a real perspective of the huge size of this relatively simple engine, and the beast it powered.
This video is incredibly rich in how the combustion chamber process works. I just love the absolute clarity you present each function. Im so glad I found it. I have wathced a bunch of vids about the V2 but this tops it all. The combustion chamber was the work of a great mind. Thank you soooo much. By the way, how was the fuel ignited? I read the alchohol was somewhere 200 proof, but even at this concentration I dont think it ignites on contact with liquid oxygen like Hydrogen does.
At Minute 3:28 the top of the engine is shown, what are the blanked off connections intended for, are they something to do with the pipes running vertically from the lower portion of the exit nozzle, and if so why were they needed? And what is the white/grayish material between the mixing chambers and on top of the engine itself, some form of insulation perhaps? What is the history of this engine, it looks to have seen better days? P.S. After watching another of your fine videos I now understand that the excellent displays consist of salvaged and restored V2 parts, it's a very interesting display.
+Dan NZ Hi Dan and thanks for posting. The combustion chamber shown at that point is a relic recovered from the underground factory in Nordhausen. It had rested in up to feet of water for 60 years hence the less than mint condition. The relic is on permanent loan to the museum I think. The blanked off connections are the LOX inlet ports (18 of them) - the caps are to protect the threads and prevent debris entering the internal spaces of the motor during transit and storage adventures. Although the V2 motor system was primitive by today's standard it was unnecessarily complex (an odd situation for a primitive product) and as a result it was very fragile and was easily corrupted by corrosion and foreign bodies degrading the function and delivery capacity of thin tubes, jet ports, and valves. This situation is not unique to the V2, as I'm sure you realise, and in general, a modern motor would still need transit capping like this. The greyish material you refer to is blobs of cured cement mix! It originates from some repair or construction work carried out at the factory immediately above the chambers and the mix splashing down on them. It's difficult to say when this occurred exactly but I have looked at it closely and looked at where in the factory they were found, and I think it is quite likely the 'accident' happened in the active '44/'45 period. Indeed it's a possible explanation of why these (there are a number of them in existence) chambers have survived until today. They were rejects, perhaps because of the mishap with the cement mix, and survived just because they were relegated to a part of the factory facility, for refurbishment, and the Russians did not think it worthwhile to take them (they had plenty of good chambers available). I hope this helps. KR RJD ANTV
Absolutely love your videos, thank you. Have you done a video showing a comparison to the F1 engine, showing how the Apollo program built upon these items?
Do you have any information on the thrust chamber pressure? The delta P between chamber and fuel/oxidizer needs only to be enough to secure atomizing and mixing but the propellant turbo pump has to deliver fuel/oxidizer at chamfer pressure plus atomization pressure. I imagine the alcohol mix picked up plenty of heat in its passage through the engine jacket. If you're obtaining design flow at domestic water pressure my guess (judging from study of the pump video and estimating dimensions and impeller RPM at 4500) is the pump delivered perhaps 500 PSI at rated volume. I also eyeball the engine had roughly a 7 1/2" throat dia. But allow me a healthy fudge factor. Sorry about the Imperial units. At my age, you're lucky it isn't in cubits. Got any specific impulse figures?
According to Wikipedia the V-2's engine has a chamber pressure of 220 psi. According to astronautix.com LOX/alcohol rockets achieve a specific impulse at sea level of 284s and in vacuum (if I read it correctly) of 338s.
Thank you for the great presentation, I found it very informative and learned a lot from watching. At 12:58 when you show the simpler upper nozzle, has this been manufactured in two parts and later joined by some method? You mentioned steel and brass as two metals used in the construction of this mixing chamber, can you tell me what the actual combustion chamber and exit nozzle were made from? You also mentioned water and alcohol as fuel being injected, I don't understand this reference as I had assumed that only relatively pure alcohol made from potatoes was used as the fuel. Thanks
+Dan NZ Hi again Dan. The brass/bronze alcohol injection nozzles shown were of a one and two piece design. The ones with the small outlet hole are made in two parts, with the components forced together in a press and a thin outer edge against the visible seam collar pressed in to lock it togethe. A joining compound of some kind is in evidence on the separated parts but this seem fairly light and provides little bond strength (they are virtually impossible to separate, but by cutting down the centre and restoring the surface of a cut half carefully you can just trace the outlines of the two parts with a hand lens and the parts can be easily separated once cut through like this). The injectors with the larger size hole are made in one piece as there is sufficient clearance to firstly bore and then introduce a milling tool with enough overhang to create a swirl chamber that has a greater internal diameter than the exit port. To reduce the burn temperature (and other factors) 25% water was added to the ethanol (derived as you say from potatoes). I hope this helps. KR RJD ANTV
+Astronomy and Nature TV Thank you for your reply and for the additional information, I wonder in the first case if that the two parts of the smaller injectors might have been brazed or silver soldered together as this would have been a very simple, quick and inexpensive method to join the two halves while retaining a high strength and temperature resistant join. I also wonder if the 25% water was partly the result of a less than perfect distillation process that ultimately proved to be a desirable if unplanned addition to the fuel? The water would certainly have flashed into steam during the combustion process thereby producing additional volume in the combustion chamber and greater exhaust speeds, but I also wonder if the combustion temperatures were high enough to break the water molecules apart so that the engine was infact also burning hydrogen with a little bit of extra oxygen? Although I can't see how this would be efficient.
What was the chamber pressure just outside of the nozzle while the engine was running, and how would that change the spray pattern or mixing of the fuel and oxygen? Your tests were at 1 bar.
What kept the burn in the lower part (combustion chamber) contained so as not to reach the upper part (the 18 pots with the nozzles and LOX sprayer-head) and burning there and utimately through the nozzle-pathways into the alcohol-manifold of the pot and also into the LOX sprayer head into the LOX feeding tube, etc. to avoid a cataclysmic event?
+RogerWilco Hi there, the museum where we videoed the combustion chamber is the Deutsches Historisches Museum, Berlin (German History Museum). KR RJD ANTV
Vielen Dank für den Film mit den hochinteressanten Details. I actually followed your video with my original A-Stoff and B-Stoff nozzles next to me, inspecting them as you did. I learned a lot of new stuff from your video. Thank you very much.
Werner Heisenberg - where would one get A4 parts? My village in England was one of the first places to get hit, and apparently the place was searched for every last bit of the missile.
Fascinating. Thank you for the detailed description of just this one small aspect of the V2 engine. I do hope you post (have posted?) more. People usually vastly underestimate the thought and engineering that goes into Rocket Science. Just watch the movie "Gravity" to see what I mean.
So interesting. Thank you. One can only imagine how much research went into designing a functional burner. No wonder it cost so much to the German economy
Great video, very interesting to see the detailed tech of 1943. The A4 had swirl nozzle injectors and double walled combustion chambers. 20 years later the Rocketdyne F-1 for the SaturnV had straight through injectors and a clumsy brazed tube combustion chamber construction, so far behind this German technology one has to question either Von Braun's sanity or usefulness. Of course the real rocket scientist was Korolev who in 1969 perfected the NK-15 (bought today by the USA as the bigger RD-180 etc).
Hi Graham. You've posted a bunch of messages, and the above message is the least odd of the messages posted. I've passed it as a type specimen for the sake of viewer curiosity. I've deleted the rest due to a tangle of baseless opinions, ranging from the denial of the Moon landing to youthful 'Bob-the-Builder' ideas about rocket engine design responsibility that are just plain tedious at the tail end of 2019. I just can't be bothered to pretend I care about the internet spawned nonsense you mistake for worthwhile comment. I'm a keen a supporter of free speech and freedom of expression - as I'm sure you are - but really, empty twaddle is well represented on the internet, it's bursting with it. So verily brother I beseech you, post it somewhere else - a private diary would be useful (for us anyway, as we can carry on believing in our liberal myth that the education system hasn't failed us - to a frightening degree). Take this as a friendly tip from one organised being to another: stop reading material that just homes-in on your off-axis fascinations. You're not stupid, so check out your local adult education centre and start an S101 primer. Find out how the steady, reliable canons of rational thought and empirical evidence accumulate to a peripherally frangible yet fully ramified and verifiable science. Yes, everyone is entitled to an opinion but save those busy fingers; anything more splenetic than "Gee, thanks for the tip, I'll think about it" - isn't going to reach the screen here. KR RJD A&NTV
Mr Dalby, thank you so much for these amazing videos, really, if is possible, i would like to see a video about the water/alcohol and liquid oxygen pump and the pump engine system. thanks
Hi Niklas, thanks for the good question. On the face of it, LOX looks like a strong candidate for engine cooling purposes - but the negatives stack up pretty quick. The German rocketeers of 1935, struggling with technology in its infancy, ruled out LOX as a coolant from page one. There's a hierarchy of reasons that start with the fact that cooling transfer performance will be poor because the LOX won't stay liquid long enough (regardless of pressure). The engine's design would need radical changes in plumbing and construction materials, making it significantly more complicated. The risk level is not symmetrical on almost every critical moment of fuel vs LOX analysis (minimising explosions, contamination consequences, hardware survival overtime etc.) and boils down favouring fuel as the 'safer' coolant. There are other secondary objections too. These are real challenges even today - 80 years ago, they were impossibilities. KR RJD A&NTV
@@RocketPlanet Thank you very much for the good answer. I've just checked the F1 and Rs-25 and neither of them uses lox for cooling, you learn something new every day - or at least on the good days!
That double wall made it possible to use this design. By bringing the alcohol up through that passage, it kept the combustion chamber cool enough not to just melt. Early on that was a problem, and thats Vonbrauns solution. It worked.
Great information l love it thanks for posting.. great work..
12 років тому+1
Was there a gasket, washer, or sealant on the various nozzles originally? What would the thermal effects be on the fit of the nozzles, particularly the lox one considering there are different metals in use? I like the way the Heath Robinson flow checker is better engineered than the rocket and incidentally they are some top quality Dr. Strangelove shades. I would like to state for the record I ask merely for curiosity and have no intention of building a V2.
Flow is proportional to the square root of the pressure difference between the inlet and the atmosphere. So doubling the pressure doesn't double the flow. You only get 40% more flow ie. square root of 2.
Actaully quite a lot going on in the top of that engine. I imagine this is mostly the result of a lot of improvisation and trial and error as no one knew just how to build a rocket engine yet. All those brass fittings and little holes make me think of a giant carburetor!
It is a good overview, but the speaker does get sidetracked easily and incorporates a lot of irrelevancies. I find it quite frustrating waiting for him to progress to the next meaningful section.
Indeed, this thing would have been a devastating and decisive weapon if it could hit targets with sufficient accuracy. But back then, there were no electronics or computers to do it.
My guess would be that there would be more heating of the cryogenic oxygen than cooling of the metalwork . The oxygen needs to be gaseous to react so needs to take a good deal of heat from the fuel (heated by combustion)
Odd the internal wall is thicker, while the outer wall must? Sustain a higher pressure, perhaps 50-100psi higher than internal pressure. However internal must sustain higher temperature and more variations in pressure perhaps?. I'm quite surprised the thin steel can sustain this pressure ... 2000psi perhaps?
Hi Erik. Certainly an automatic cam and multi-spindle lathe of some sort and as you say most probably Traub. I have a list of some of the machines used in the biggest factory workshop in Peenemünde (Fertigungshalle Eins or F1) and there were 6 Traub machines listed but no mention of the model or type only a factory machine number without a key. KR RJD A&NTV
Cooling. Difficulty at keeping alochol at or even near 100% concentration. Alcohol is hydrophilic, so it will naturally pick up water from the air. This effect slows the more it is diluted, so there is a point where the water-pickup effect is slowed to the point of not changing much in the brief times the fuel tanks are opened or unsealed vs. reducing the effect of the fuel. This is why when you buy rubbing alcohol in the drug store it is not 100%.
First man made object to exit our atmosphere. A direct forerunner to our mighty Saturn V rocket propulsion system. Much as a rail way gun in ballistic performance but not with the explosive shove of burning propellent in a barrel. They begin to slow after initial blast, rockets start very slowly but soon gather ever increasing speed till earth’s gravity is overcome to enter near space. All the basic requirements to enable super sonic flight in a parabolic ellipse out of the thermosphere with controlled re entry after propellent fuel consumption. With out frictional heat destruction upon descent. Unfortunately weaponized, it was however a brilliant example of problem solving to create especially in the time frame it was constructed. Thrust is useless unless contained and controlled for flight in desired trajectory. Such engineering could be used in less destructive rolls as in exploration of the vacuum of space. Once free of launch planet gravity very little fuel required to speed from one gravitational pull to another in the use of travel from one planet to another. Of coarse many computations required to time properly. A flight to round Mars and re enter earth’s atmosphere with a recoverable rocket not beyond the realm of this technology. Again unfortunately the rockets we know are in the majority used to deliver the destructive capabilities of nuclear type devices such as hydrogen war heads. If we look at history it is a trait of man kind to war on one another. Scientists can work for peaceful improvement or for destructive forces.
I love all your scientific expo say of german expertise during second world war very educational, technology that change the world and the planetary travel is no longer a dream, I hope those knowledge we used with love and care and not for oppresion of any creature here in our planetary or the entire universe
From their other videos it seems like a mixture of both, some from parts of Europe where the V2s fell, some that were in places where they were being investigated after failing, presumably some that were left over when the US/Soviets/British/etc were done researching them, and so on.
They were leftovers from when the factory was abandoned. After the allies took whatever parts they wanted they blew up the entrances. After the cold war they were re-opened and all these parts were still on the ground.
That is a fantastic demonstration on how the injector nozzles worked! Thanks for sharing the knowledge!
Agreed. You can see the pattern, the swirl (vortex?) and the additional jets. Very impressive in design and here.
With today's slow-motion tech, it would be awesome to see a super slow-mo video of the water spinning radially out of the swirl injector!
It's been sad to see Hollywood ignore the Wernher Von Braun story and do their best to edit his efforts in every way possible. I have never understood why so many people want to ignore that the V2 / A4 is a direct relative to the Saturn 5 moon rocket. Anyway that injector would make for a very cool shower nozzle and bathroom novelty item.
American don't want to to highlight the contribution of German scientists. Even these days American and British are competing with Germany. They are making every effort to show the German low.
@@Sk_max-k3m Not really, USA actually appointed Von Braun to NASA centers first director 1960 and held the position in 10year until 1970. Perhaps todays politically correct democrat-USA trying hide and covers up its the past. Democrats favorite president JFK was a friend of Wernher Von Braun, who was the first director of the NASA Center bearing JKFs name, the Kennedy Space Center. Von Braun did so much for his new country and americans today should be thankful to him.
Wernher von Braun was of questionable moral character, like many German intellectuals of the time, opportunitistically playing along with Nazi ideology, despite knowing that it was bullshit. Having thousands of people toil and die in factories and forced labor camps to produce his rockets. Yes, he knew what the SS was up to, in full.
Could you praise his engineering genius, pioneering spirit, and dedication to manned spaceflight, without putting him on a pedestal? Of course you could. But even if Hollywood likes to pretend to favor "flawed heros", in reality, something like that is way to nuanced for the entertainment industry. They prefer to treat their audience like idiots who can only ever deal with black and white morality.
And to be fair, I can see where they are coming from, given how prone people are to knee jerk reactions.
@@gesamtszenario
Didn't the U.S. imprison more people in labor camps than were ever used in the V2 project? And the British government was doing a Bolshevik style farm collectivisation through the war ag department, including killing farmers that refused to cooperate. Plus the explicit war crime of the dehousing bombing campaign, bombing women and children in their houses in working class districts of Germany. The targeting of civilians is a war crime. You aren't one to be lecturing on morals.
also he was kind of a nazi...
I personally would beg to differ on one point. The switch from steel to brass would have been motivated by tooling life considerations. These nozzles would have been made on an automatic lathe and switching materials from steel to an easily machined material like leaded brass or leaded bronze gunmetal would enable an automatic lathe to double or tripple its nozzles made per day output. This is because the machine can be run faster with less time lost in sharpening and reseting tools and in replacing broken tools. This type of automatic lathe is cam operated and can make a nozzle like this in less than a minute. They are rarely used now because computer controlled lathes are used instead - unless huge numbers of identical components are required, like for instance the small brass screws for plugs and sockets are still made on cam operated automatic lathes.
There is no absolute need of an automatic cam lathe to make those injectors. A revolving turret lathe would be slower but give finished parts with threading done. Of course, using brass or bronze instead of steel is less punishing for tools, but it is also more difficult to find in wartime contingency. If you read the 4year old comment of Douglas Abbott, you can also consider that form tools save a lot of machining time and efforts. In this case, saving on sharpening is actually valuable.
But look closely at the multi-jet nozzle ant you will see that it is hollow and the back side shows a small recess indicating it is probably a two part assembly to form an inner chamber for the whirlpool to form and spread the liquid on all holes and not only the central one.
This is about as good as it gets as far as explaining things -- truly impressive.
This was one of the best videos that I have ever seen on YT. It was too the point and very efficiently done. Good job. Greetings from Apache Junction, Arizona.
These videos are fantastic! Great being able to see the actual hardware.
Makes it pretty obvious why the US military, when they had their engineers look at the plant, decided not to only grab the stuff, but grab the folks who designed it. That was as good as engineering got in the 40s.
I too wish the US would continue to remain more public, and also teach more about the crucial importance of Science in all we do/ are!
So chineses can steal technology?
@@dirtbikerswe1979 Actually, the Small Hats do most of the stealing, then they sell it to China. At least one Small Hat went to prison for it; in that case, it was military science technology.
It is mentioned at about 13min into the video that you can see the lines from the lathe work on the nozzle. Strictly speaking they must a have used a form tool to make the outside shape of the nozzle. This is revealed by the fact that the machining lines are concenctric rather than spiral. Spiral lines lines are produced by a single point lathe toole and concentric lines are produced from a form tool imposing a shape in the metal. I know it seems a small useless point but I think it is best to be accurate about these things.
Hi Douglas - thanks for that comment - it's not useless at all. Far from it, I spend much time explaining that there are no mind-bendingly complex ideas in engineering - alone they are always simple, and easily comprehended but there are many compounded in layers and all very particular. Thanks for highlighting that 'particular'. KR RJD A&NTV
They'd have used a capston/turret lathe to make them. Quite simple to make to be fair
@@Spikejones5001 Actually, I would think they would have used a 'Swiss Lathe" to make them, the same tool used to make the components of Swiss watches. The Germans manufactured these automatic lathes used in Swiss watch factories, programmed by cams. Those lathes were unique in being able to perform a number of simultaneous operations at the same time, and very quickly.
Every detail counts.
The most fascinating thing about this truly awesome video is the fact that 16 (and counting?) people gave it a 'dislike'. I mean; why?
To be fair this DIY explanation is a bit complicated and hard to repeat at home... ;)
At 13:30 About the steel vs brass nozzles.
I wonder if corrosion was really an issue. After all, they are not re-usable. And I assume that they are used as fast as they are produced.
Maybe they are just faster/easier to produce from brass stock.
I doubt they would have used so much scarce copper without a very good reason. Copper was becoming unobtainium in late war germany.
I am sitting here, for the second time, with my mouth open and thoroughly entranced by this machine, the video and the information. Great work.
Very cool video. The sight of one of those single injectors in hand gives one a real perspective of the huge size of this relatively simple engine, and the beast it powered.
Fascinating to see the engineering that went into the injector design.
This was easily the best demonstration i ever seen about this. Thank You wery much for making such great content!
spectacular demonstration and explanation. thank you for the fantastic video!
Fantastic video, Please do more on the A4, this is the sort of detail many people are looking for!
This video is incredibly rich in how the combustion chamber process works. I just love the absolute clarity you present each function. Im so glad I found it. I have wathced a bunch of vids about the V2 but this tops it all. The combustion chamber was the work of a great mind. Thank you soooo much. By the way, how was the fuel ignited? I read the alchohol was somewhere 200 proof, but even at this concentration I dont think it ignites on contact with liquid oxygen like Hydrogen does.
Awesome video, love the real technical stuff! A video on the turbo pump and steam generator would be great
very good teaching and arranging the resources in to the video excellent
Beautiful spray pattern nozzle design!
At Minute 3:28 the top of the engine is shown, what are the blanked off connections intended for, are they something to do with the pipes running vertically from the lower portion of the exit nozzle, and if so why were they needed? And what is the white/grayish material between the mixing chambers and on top of the engine itself, some form of insulation perhaps?
What is the history of this engine, it looks to have seen better days?
P.S. After watching another of your fine videos I now understand that the excellent displays consist of salvaged and restored V2 parts, it's a very interesting display.
+Dan NZ Hi Dan and thanks for posting. The combustion chamber shown at that point is a relic recovered from the underground factory in Nordhausen. It had rested in up to feet of water for 60 years hence the less than mint condition. The relic is on permanent loan to the museum I think. The blanked off connections are the LOX inlet ports (18 of them) - the caps are to protect the threads and prevent debris entering the internal spaces of the motor during transit and storage adventures. Although the V2 motor system was primitive by today's standard it was unnecessarily complex (an odd situation for a primitive product) and as a result it was very fragile and was easily corrupted by corrosion and foreign bodies degrading the function and delivery capacity of thin tubes, jet ports, and valves. This situation is not unique to the V2, as I'm sure you realise, and in general, a modern motor would still need transit capping like this. The greyish material you refer to is blobs of cured cement mix! It originates from some repair or construction work carried out at the factory immediately above the chambers and the mix splashing down on them. It's difficult to say when this occurred exactly but I have looked at it closely and looked at where in the factory they were found, and I think it is quite likely the 'accident' happened in the active '44/'45 period. Indeed it's a possible explanation of why these (there are a number of them in existence) chambers have survived until today. They were rejects, perhaps because of the mishap with the cement mix, and survived just because they were relegated to a part of the factory facility, for refurbishment, and the Russians did not think it worthwhile to take them (they had plenty of good chambers available). I hope this helps. KR RJD ANTV
Excellent, good to have such a detailed explanation of the components. Thanks and look forward to more!
Absolutely love your videos, thank you. Have you done a video showing a comparison to the F1 engine, showing how the Apollo program built upon these items?
What determines the size of these calibrated orifices for the mixing stage?
Do you have any information on the thrust chamber pressure? The delta P between chamber and fuel/oxidizer needs only to be enough to secure atomizing and mixing but the propellant turbo pump has to deliver fuel/oxidizer at chamfer pressure plus atomization pressure. I imagine the alcohol mix picked up plenty of heat in its passage through the engine jacket.
If you're obtaining design flow at domestic water pressure my guess (judging from study of the pump video and estimating dimensions and impeller RPM at 4500) is the pump delivered perhaps 500 PSI at rated volume. I also eyeball the engine had roughly a 7 1/2" throat dia. But allow me a healthy fudge factor.
Sorry about the Imperial units. At my age, you're lucky it isn't in cubits.
Got any specific impulse figures?
According to Wikipedia the V-2's engine has a chamber pressure of 220 psi. According to astronautix.com LOX/alcohol rockets achieve a specific impulse at sea level of 284s and in vacuum (if I read it correctly) of 338s.
This guy is a brilliant teacher!
Thank you for the great presentation, I found it very informative and learned a lot from watching.
At 12:58 when you show the simpler upper nozzle, has this been manufactured in two parts and later joined by some method?
You mentioned steel and brass as two metals used in the construction of this mixing chamber, can you tell me what the actual combustion chamber and exit nozzle were made from?
You also mentioned water and alcohol as fuel being injected, I don't understand this reference as I had assumed that only relatively pure alcohol made from potatoes was used as the fuel.
Thanks
+Dan NZ Hi again Dan. The brass/bronze alcohol injection nozzles shown were of a one and two piece design. The ones with the small outlet hole are made in two parts, with the components forced together in a press and a thin outer edge against the visible seam collar pressed in to lock it togethe. A joining compound of some kind is in evidence on the separated parts but this seem fairly light and provides little bond strength (they are virtually impossible to separate, but by cutting down the centre and restoring the surface of a cut half carefully you can just trace the outlines of the two parts with a hand lens and the parts can be easily separated once cut through like this). The injectors with the larger size hole are made in one piece as there is sufficient clearance to firstly bore and then introduce a milling tool with enough overhang to create a swirl chamber that has a greater internal diameter than the exit port. To reduce the burn temperature (and other factors) 25% water was added to the ethanol (derived as you say from potatoes). I hope this helps. KR RJD ANTV
+Astronomy and Nature TV Thank you for your reply and for the additional information, I wonder in the first case if that the two parts of the smaller injectors might have been brazed or silver soldered together as this would have been a very simple, quick and inexpensive method to join the two halves while retaining a high strength and temperature resistant join.
I also wonder if the 25% water was partly the result of a less than perfect distillation process that ultimately proved to be a desirable if unplanned addition to the fuel? The water would certainly have flashed into steam during the combustion process thereby producing additional volume in the combustion chamber and greater exhaust speeds, but I also wonder if the combustion temperatures were high enough to break the water molecules apart so that the engine was infact also burning hydrogen with a little bit of extra oxygen? Although I can't see how this would be efficient.
I appreciate your videos. There was a lot of design and thought that went into development of the engine. Cooling and mixture .. ..
This is great stuff, some more videos would be very welcome.
Amazing historical artifacts. Thank you.
What was the chamber pressure just outside of the nozzle while the engine was running, and how would that change the spray pattern or mixing of the fuel and oxygen? Your tests were at 1 bar.
Fantastic video. You really do a great job explaining and demonstrating things.
Greetings from New England. Excellent job once again
Love these videos, the word you were looking for was tangential, hence the swirl. Why was the pressure gauge aimed away from the camera?
Awesome. I enjoy the detailed explanation and thoroughly enjoyed seeing the practical demonstration.
great video
1000X better than al the history channel propaganda
Do you have any information on how the main nozzle itself and the pots were built?
What kept the burn in the lower part (combustion chamber) contained so as not to reach the upper part (the 18 pots with the nozzles and LOX sprayer-head) and burning there and utimately through the nozzle-pathways into the alcohol-manifold of the pot and also into the LOX sprayer head into the LOX feeding tube, etc. to avoid a cataclysmic event?
excellent. please make some detailed video on V2 turbo pump and gyroscope and servo system.
What an awesome channel!
Fantastic handicraft, and today we just 3D-print the stuff :-)
Nothin like free labor!
Nice detailed presentation. Which museum would this be that is referenced?
Quite a bit of high tech engineering.
+RogerWilco Hi there, the museum where we videoed the combustion chamber is the Deutsches Historisches Museum, Berlin (German History Museum). KR RJD ANTV
Vielen Dank für den Film mit den hochinteressanten Details. I actually followed your video with my original A-Stoff and B-Stoff nozzles next to me, inspecting them as you did. I learned a lot of new stuff from your video. Thank you very much.
Werner Heisenberg - where would one get A4 parts? My village in England was one of the first places to get hit, and apparently the place was searched for every last bit of the missile.
Want to understand how the combustion chamber looked & worked.
If you find the video please share the link 🔗 here
An excellent video. I hope that you will make more video's on rocket technology.
Fantastic, as ever. Thanks you very much Robert!
Fascinating. Thank you for the detailed description of just this one small aspect of the V2 engine. I do hope you post (have posted?) more. People usually vastly underestimate the thought and engineering that goes into Rocket Science. Just watch the movie "Gravity" to see what I mean.
Am wondering if the actual Cartier 'Tank' watch. Very nice in any case.
So interesting. Thank you. One can only imagine how much research went into designing a functional burner. No wonder it cost so much to the German economy
I like the fact that I am a plumber and all this makes sense to me. Great video very informative Thank you 🙏
Those little nozzle flow tests look like the kind of work Werner von Braun would have done when he designed them. I like it!
Didn‘t he design the nozzles?
Great video, very interesting to see the detailed tech of 1943. The A4 had swirl nozzle injectors and double walled combustion chambers. 20 years later the Rocketdyne F-1 for the SaturnV had straight through injectors and a clumsy brazed tube combustion chamber construction, so far behind this German technology one has to question either Von Braun's sanity or usefulness.
Of course the real rocket scientist was Korolev who in 1969 perfected the NK-15 (bought today by the USA as the bigger RD-180 etc).
Hi Graham. You've posted a bunch of messages, and the above message is the least odd of the messages posted. I've passed it as a type specimen for the sake of viewer curiosity. I've deleted the rest due to a tangle of baseless opinions, ranging from the denial of the Moon landing to youthful 'Bob-the-Builder' ideas about rocket engine design responsibility that are just plain tedious at the tail end of 2019. I just can't be bothered to pretend I care about the internet spawned nonsense you mistake for worthwhile comment.
I'm a keen a supporter of free speech and freedom of expression - as I'm sure you are - but really, empty twaddle is well represented on the internet, it's bursting with it. So verily brother I beseech you, post it somewhere else - a private diary would be useful (for us anyway, as we can carry on believing in our liberal myth that the education system hasn't failed us - to a frightening degree). Take this as a friendly tip from one organised being to another: stop reading material that just homes-in on your off-axis fascinations. You're not stupid, so check out your local adult education centre and start an S101 primer. Find out how the steady, reliable canons of rational thought and empirical evidence accumulate to a peripherally frangible yet fully ramified and verifiable science. Yes, everyone is entitled to an opinion but save those busy fingers; anything more splenetic than "Gee, thanks for the tip, I'll think about it" - isn't going to reach the screen here. KR RJD A&NTV
@@RocketPlanet Jolly good.
@@RocketPlanet Thank you for your de-trolling prowess!
Mr Dalby, thank you so much for these amazing videos, really, if is possible, i would like to see a video about the water/alcohol and liquid oxygen pump and the pump engine system. thanks
Great historical video. Much a appreciate.
Well done! Looking forward to more great videos like this! I really enjoy how well the details are shown.
Safe to assume that the alcohol running through the nozzles was liquid and close to compressibility of water?
I don't think I could find better technical explanation . Much better than any of the nonsense you get on TV.
Fascinating stuff, thanks for this great video.
Wonderful artifacts of German scientists and technologies of 1930's and 40's.👏👏😲
Thank you very much for this video with detailed information!
Why would any person push the dislike button.
This is great stuff.
Excellent. Good detail and entertaining way of conveying information.
Why was the alcohol/water mixture used to cool the nozzle and not the lox?
Hi Niklas, thanks for the good question. On the face of it, LOX looks like a strong candidate for engine cooling purposes - but the negatives stack up pretty quick. The German rocketeers of 1935, struggling with technology in its infancy, ruled out LOX as a coolant from page one. There's a hierarchy of reasons that start with the fact that cooling transfer performance will be poor because the LOX won't stay liquid long enough (regardless of pressure). The engine's design would need radical changes in plumbing and construction materials, making it significantly more complicated. The risk level is not symmetrical on almost every critical moment of fuel vs LOX analysis (minimising explosions, contamination consequences, hardware survival overtime etc.) and boils down favouring fuel as the 'safer' coolant. There are other secondary objections too. These are real challenges even today - 80 years ago, they were impossibilities. KR RJD A&NTV
@@RocketPlanet Thank you very much for the good answer.
I've just checked the F1 and Rs-25 and neither of them uses lox for cooling, you learn something new every day - or at least on the good days!
I understand maby 10 percent of what you say but I still love watching your videos
Hi, is it Ethanol and water or Methanol and water fuel? What percentage?
That double wall made it possible to use this design. By bringing the alcohol up through that passage, it kept the combustion chamber cool enough not to just melt. Early on that was a problem, and thats Vonbrauns solution. It worked.
Thanks Robert great video as usual.
Excelente trabajo. Gracias por divulgar esta tecnología y por favor continúen con esa gran labor.
Great information l love it thanks for posting.. great work..
Was there a gasket, washer, or sealant on the various nozzles originally? What would the thermal effects be on the fit of the nozzles, particularly the lox one considering there are different metals in use?
I like the way the Heath Robinson flow checker is better engineered than the rocket and incidentally they are some top quality Dr. Strangelove shades.
I would like to state for the record I ask merely for curiosity and have no intention of building a V2.
I expect those issues were not a concern as these were i tended for a single use and operated for a small amount of time.
muy interesante muchas gracias
Nice watch Cartier Tank? You should make a watch collection vid!
Awesome documentation and explanation. Well done.
Flow is proportional to the square root of the pressure difference between the inlet and the atmosphere. So doubling the pressure doesn't double the flow. You only get 40% more flow ie. square root of 2.
Really interesting video.
Thanks.
Actaully quite a lot going on in the top of that engine. I imagine this is mostly the result of a lot of improvisation and trial and error as no one knew just how to build a rocket engine yet.
All those brass fittings and little holes make me think of a giant carburetor!
It is a good overview, but the speaker does get sidetracked easily and incorporates a lot of irrelevancies. I find it quite frustrating waiting for him to progress to the next meaningful section.
thanks for posting this video , you are better then the science channel or discovery
Awesome. Thanks for sharing
Indeed, this thing would have been a devastating and decisive weapon if it could hit targets with sufficient accuracy. But back then, there were no electronics or computers to do it.
Great presentation. Is that material open to the public.
@14:08 Polarized glasses and a polarized lens I'm guessing.
Excellent video! Thank you!
great video
Thanks we learned a lot
Love the detail
My guess would be that there would be more heating of the cryogenic oxygen than cooling of the metalwork . The oxygen needs to be gaseous to react so needs to take a good deal of heat from the fuel (heated by combustion)
Odd the internal wall is thicker, while the outer wall must? Sustain a higher pressure, perhaps 50-100psi higher than internal pressure.
However internal must sustain higher temperature and more variations in pressure perhaps?.
I'm quite surprised the thin steel can sustain this pressure ... 2000psi perhaps?
An excellent video.
I'm guessing those brass injector nozzles were made on a Traub Screw machine. They are still in business.
Hi Erik. Certainly an automatic cam and multi-spindle lathe of some sort and as you say most probably Traub. I have a list of some of the machines used in the biggest factory workshop in Peenemünde (Fertigungshalle Eins or F1) and there were 6 Traub machines listed but no mention of the model or type only a factory machine number without a key. KR RJD A&NTV
Lol, I thought we were going to see a UL stamp on it, somewhere.
You mention in the comments that the amount of water in the fuel was 25%. What was the purpose of the water?
Cooling. Difficulty at keeping alochol at or even near 100% concentration. Alcohol is hydrophilic, so it will naturally pick up water from the air. This effect slows the more it is diluted, so there is a point where the water-pickup effect is slowed to the point of not changing much in the brief times the fuel tanks are opened or unsealed vs. reducing the effect of the fuel. This is why when you buy rubbing alcohol in the drug store it is not 100%.
First man made object to exit our atmosphere. A direct forerunner to our mighty Saturn V rocket propulsion system.
Much as a rail way gun in ballistic performance but not with the explosive shove of burning propellent in a barrel. They begin to slow after initial blast, rockets start very slowly but soon gather ever increasing speed till earth’s gravity is overcome to enter near space.
All the basic requirements to enable super sonic flight in a parabolic ellipse out of the thermosphere with controlled re entry after propellent fuel consumption. With out frictional heat destruction upon descent.
Unfortunately weaponized, it was however a brilliant example of problem solving to create especially in the time frame it was constructed. Thrust is useless unless contained and controlled for flight in desired trajectory. Such engineering could be used in less destructive rolls as in exploration of the vacuum of space. Once free of launch planet gravity very little fuel required to speed from one gravitational pull to another in the use of travel from one planet to another. Of coarse many computations required to time properly. A flight to round Mars and re enter earth’s atmosphere with a recoverable rocket not beyond the realm of this technology.
Again unfortunately the rockets we know are in the majority used to deliver the destructive capabilities of nuclear type devices such as hydrogen war heads. If we look at history it is a trait of man kind to war on one another. Scientists can work for peaceful improvement or for destructive forces.
I love all your scientific expo say of german expertise during second world war very educational, technology that change the world and the planetary travel is no longer a dream, I hope those knowledge we used with love and care and not for oppresion of any creature here in our planetary or the entire universe
So far it still remains a dream in any meaningful sense.
Very interesting.
Very good !
Oh yes - this is the good stuff
What is the history on these vintage parts? Had they ever flown or were they discovered after Germany's surrender?
From their other videos it seems like a mixture of both, some from parts of Europe where the V2s fell, some that were in places where they were being investigated after failing, presumably some that were left over when the US/Soviets/British/etc were done researching them, and so on.
They were leftovers from when the factory was abandoned. After the allies took whatever parts they wanted they blew up the entrances. After the cold war they were re-opened and all these parts were still on the ground.