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#51
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"Keith Willshaw" wrote
"Merlin Dorfman" wrote in message Eugene Griessel ) wrote: ... : Mmmmm - the steel piston which ran in the tube of the V1 launch ramp : and was powered by steam was quite a a long object. About 16 foot or : somewhere thereabouts. It would be interesting to see how this worked : in a curved steel tube. Is there a Web resource that explains how the V1 was boosted into the air? Was the pulse jet engine capable of being started on the ground or was it started after the missile had attained a certain air speed? Thanks. The pulse jet was started on the ground, the catapult was needed for the same reason catapults were used on aircraft carriers and aboard cruisers for launching seaplanes, it enabled the use of a short ramp. Keith I agree pulse jets can run when stationary. Here is a more recent valveless variant. I have no idea how they work, but they are more or less a tube with a U bend and a bulge. I find it really amazing. I first saw it on Junkyard Wars or whatever it is called in the UK. http://www.jetzilla.com/Vol01Num02/j...html#Article_1 A U-Bend "Lockwood" pulse jet. Mo- http://www.aardvark.co.nz/pjet/ http://www.aardvark.co.nz/pjet/lhkart.shtml http://www.aardvark.co.nz/pjet/mylockwood.shtml |
#52
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"AnyBody43" wrote in message om... I agree pulse jets can run when stationary. Here is a more recent valveless variant. I have no idea how they work, but they are more or less a tube with a U bend and a bulge. I find it really amazing. I first saw it on Junkyard Wars or whatever it is called in the UK. Scrapheap challenge, in the UK version the winning team built a pulsejet from scratch and used it to power a car http://www.channel4.com/science/micr...ges/jet_racer/ Keith |
#54
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In message , robert
arndt writes snip The Argus-Schmidt pulsejet was incapable of launching the V-1 by itself so a steam-driven piston got it moving off the launch ramp at an appreciable speed which gave enough forward energy to open the duct flaps and commence the pulse detonation cycle. The V-1 firing on the ramp does not mean it was operable. It was fired for exactly 7 seconds to warm it up to operating temperature. Afterwards, T-Stoff and Z-Stoff were remotely pumped into the steam generation vessel. Robert, are you quite sure about that T-Stoff and Z-Stoff? I thought that was the deadly stuff they used in the 163. Potassium Permanganate comes to mind for the V1. (But considering that I was wrong on the ski-sites, I may well be wrong here) Mike -- M.J.Powell |
#55
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(Eugene Griessel) wrote in message om...
Alan Minyard wrote in message . .. On 18 Jan 2004 21:48:27 -0800, (robert arndt) wrote: Merlin Dorfman wrote in message ... Eugene Griessel ) wrote: ... : Mmmmm - the steel piston which ran in the tube of the V1 launch ramp : and was powered by steam was quite a a long object. About 16 foot or : somewhere thereabouts. It would be interesting to see how this worked : in a curved steel tube. Is there a Web resource that explains how the V1 was boosted into the air? Was the pulse jet engine capable of being started on the ground or was it started after the missile had attained a certain air speed? Thanks. The Argus-Schmidt pulsejet was incapable of launching the V-1 by itself so a steam-driven piston got it moving off the launch ramp at an appreciable speed which gave enough forward energy to open the duct flaps and commence the pulse detonation cycle. The V-1 firing on the ramp does not mean it was operable. It was fired for exactly 7 seconds to warm it up to operating temperature. Afterwards, T-Stoff and Z-Stoff were remotely pumped into the steam generation vessel. Pressure built up until it was sufficient to shear a restraining bolt sending the launch piston up the tube carrying the launch trolley and missile with it. By the time it reached the end of the track (.5 seconds later) the missile had been accelerated at a rate of 16g up to 250 mph with the pulse jet running independently. On another thread there is dispute that a pulsejet is a form of ramjet. I think the description of the firing of the V-1 proves otherwise. Rob Wrong. The V-1 engine could operate at zero velocity, thus it was definitely NOT a "ram jet". No one, other than herr Arndt, referrers to a V-1 as having a "ram jet" engine. Al, I suggest you put your prejudice aside for a moment, reread the last paragraph and then, after wiping the egg of your face, apologise. Eugene The Germans made several types of pulse jet both valveless and valved, some which could resonate at zero intake velocity and auto ignite from compression detonation. Post war a US company called Hillier experimented with these and these are the basis of the pulse jets seen on "Junkyard Wars". The V1s engine as I recall reading somewhere could opperate sustainably from the low velocity of about 20mph. Hence it could preumably be opperated by a modest fan or a compressed air hose while stationary. The Germans also made ram jets. Most opperated well at around 200m/s or 440mph. Infact the Germans developed supersonic diffusers for ram jet cannon shells to allow ram jets to opperate at supersonic Mach 2+ speeds. The intake spike you seen on a Talos/Tartar missile, Sea Dart Missile or SR71 intake derives from German ram powered cannon shell research. One type of ram jet known as an inductor ram jet used a small rocket motor inside. This fired while ramjet was stationary and induced an airflow which could burn a pure fuel in a secondary combstiuon zone. Once at speed the rocket was switched of. Stationay thrust was about 100kg and full speed thrust was about 130kg on the test model I am recollecting. I believe stationary specific fuel plus oxidiser consumptioin was 700 seconds which is 1.5 times as good as the shuttle enignes, 4 times as good as WW2 contempoary rocket engines but about 1/3rd of the thirsty turbojets of the day. At one point the Germans were planning to used liquid fuel inductor ramjets that burned powdered coal in the secondary zone. If you've seen how effective blown powdered coal burners are in locomotives (Henschell sold such equipement) or power stations (it goes of vigorously) then this is quite feasable assuming the coal handing equiment can be made compact enough. (other coal fired ramjet ideas used a porus powdered sponge coal called schaumkhole cast into a anulus and another Lippisch designe even used a Griticule Bed. One promising designe was for an oxidiser and rocket free monopropellant inductor ramjet. Alcahol fuel (which was resitant to carbonisation and thermal cracking) was heated in a monotube boiler/tube sorounding the ramjet body. It was then flashed into high pressure vapour that provided thrust and induced a secondary airflow. Once at speed a more energy dense fuel could be used. This design was not practicable becuase of the sensitivity of thrust and fuel flow control with the systems of the day. I suspect it would be easy for the controls of today. |
#56
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"M. J. Powell" wrote in message ...
In message , robert arndt writes snip The Argus-Schmidt pulsejet was incapable of launching the V-1 by itself so a steam-driven piston got it moving off the launch ramp at an appreciable speed which gave enough forward energy to open the duct flaps and commence the pulse detonation cycle. The V-1 firing on the ramp does not mean it was operable. It was fired for exactly 7 seconds to warm it up to operating temperature. Afterwards, T-Stoff and Z-Stoff were remotely pumped into the steam generation vessel. Robert, are you quite sure about that T-Stoff and Z-Stoff? I thought that was the deadly stuff they used in the 163. Potassium Permanganate comes to mind for the V1. (But considering that I was wrong on the ski-sites, I may well be wrong here) T-Stoff is an 80% concentration of hydrogen peroxide and Z-Stoff could well have been the name for Potassium Permanganate. Can't remember off-hand and will have to check. |
#57
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#58
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In message , Eugene
Griessel writes "M. J. Powell" wrote in message ... In message , robert arndt writes snip The Argus-Schmidt pulsejet was incapable of launching the V-1 by itself so a steam-driven piston got it moving off the launch ramp at an appreciable speed which gave enough forward energy to open the duct flaps and commence the pulse detonation cycle. The V-1 firing on the ramp does not mean it was operable. It was fired for exactly 7 seconds to warm it up to operating temperature. Afterwards, T-Stoff and Z-Stoff were remotely pumped into the steam generation vessel. Robert, are you quite sure about that T-Stoff and Z-Stoff? I thought that was the deadly stuff they used in the 163. Potassium Permanganate comes to mind for the V1. (But considering that I was wrong on the ski-sites, I may well be wrong here) T-Stoff is an 80% concentration of hydrogen peroxide and Z-Stoff could well have been the name for Potassium Permanganate. Can't remember off-hand and will have to check. I think your right about the Hydrogen Peroxide. I didn't know of the alternate names for the fuels. Mike -- M.J.Powell |
#59
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In message , robert
arndt writes (Eugene Griessel) wrote in message .com... "M. J. Powell" wrote in message .. . In message , robert arndt writes snip The Argus-Schmidt pulsejet was incapable of launching the V-1 by itself so a steam-driven piston got it moving off the launch ramp at an appreciable speed which gave enough forward energy to open the duct flaps and commence the pulse detonation cycle. The V-1 firing on the ramp does not mean it was operable. It was fired for exactly 7 seconds to warm it up to operating temperature. Afterwards, T-Stoff and Z-Stoff were remotely pumped into the steam generation vessel. Robert, are you quite sure about that T-Stoff and Z-Stoff? I thought that was the deadly stuff they used in the 163. Potassium Permanganate comes to mind for the V1. (But considering that I was wrong on the ski-sites, I may well be wrong here) T-Stoff is an 80% concentration of hydrogen peroxide and Z-Stoff could well have been the name for Potassium Permanganate. Can't remember off-hand and will have to check. T-Stoff was concentrated hydrogen peroxide while Z-Stoff was either: a)Z-Stoff C, calcium permanganate or b)Z-Stoff K, sodium permanganate The V-1 combo was T-Stoff with Z-Stoff K for steam generation. The Me-163 used T-Stoff with C-Stoff (see below). A-Stoff: Liquid oxygen B-Stoff: Hydrazine hydrate (92%) + water (8%) C-Stoff: 50/50 mix of hydrazine hydrate + methanol F-Stoff: Titanium tetrachloride N-Stoff: CIF3 SV-Stoff: Nitric acid + nitrogen dioxide (RFNA) Thanks again, Robert. Very useful. Mike -- M.J.Powell |
#60
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Eunometic ) wrote:
: (Eugene Griessel) wrote in message om... : Alan Minyard wrote in message . .. : On 18 Jan 2004 21:48:27 -0800, (robert arndt) wrote: : : Merlin Dorfman wrote in message ... : Eugene Griessel ) wrote: : : ... : : : Mmmmm - the steel piston which ran in the tube of the V1 launch ramp : : and was powered by steam was quite a a long object. About 16 foot or : : somewhere thereabouts. It would be interesting to see how this worked : : in a curved steel tube. : : Is there a Web resource that explains how the V1 was boosted : into the air? Was the pulse jet engine capable of being started on : the ground or was it started after the missile had attained a : certain air speed? : Thanks. Thanks for the many answers. .... : compression detonation. Post war a US company called Hillier : experimented with these and these are the basis of the pulse jets seen : on "Junkyard Wars". Could this be Hiller? IIRC Stanley Hiller built a small copter with a pulse jet on the tip of each (of 2) rotor. The Hiller Museum in San Carlos, Calif., has a picture of the Hiller Hornet at http://www.hiller.org/exhibits/copter-news-v3n8/images/hiller-hornet.jpg, saying it had ramjets, but I'm not sure this is correct, or another copter may have had the ramjets. |
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