Turbojet powered cruise missiles

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Yes, it is difficult to say to what extent the following were results of intentional "failures" of the ADGB or real successes of the LW: Rommel's weekly situation report issued on 5 June (page 229): "Air reconnaissance showed no great increase of landing craft in Dover area. Other harbours of England's south coast not visited by reconnaissance aircraft." The report continued "Survey urgently needed of harbour moorings on the entire English south coast by air reconnaissance." Once the Invasion got under way efforts were made to photograph UK harbours and the kentish port of Ramsgate was covered by 5/123 (7th June 1944 Sortie F29/44, pilot Uffz Kallenberger, Height 750m; photos 753 and 754 used in report on the shipping there.
 
The problem is that even knowing that the ports of the South Coast were full of vessels and knowing that an invasion was imminent doesn't tell you where the landings will be made.

The German High Command was obsessed with the Calais area. As late as 18th May, in an evening situation report at the Berghof the report for the West was all about beach reconnaissance. The only one sceptical of the Pas de Calais region being the intended invasion area was Hitler himself.

"Today there were two reconnaissance missions - rather we can't call them missions. They were attempts to locate obstacles of the coast and to photograph them. A patrol of the 18th Luftwaffe Field Division on the left wing eastward of Calais noticed some movement. An exchange of fire occurred. First we thought they were our own forces, clashing with each other. But flash bulbs, spades and American flashlights were found, one man was wounded, so we have to assume that Americans had tried to photograph the obstacles. Likewise two British officers were captured at the mouth of the Somme. They had gone in with a rubber dinghy and, according to interrogation completed so far, had been dropped by a British motor torpedo boat."

The date is important. The actual reconnaissance of the real intended invasion beaches had been completed just two days earlier, so these 'raids' must have been part of Operation Fortitude. It was also just one day after the date for D-Day, initially June 5th, had been set by Eisenhower.

Cheers

Steve
 
The problem is that even knowing that the ports of the South Coast were full of vessels and knowing that an invasion was imminent doesn't tell you where the landings will be made.

Very true

The sailing distance from the Solent to Normandy and to Pas e Calais is pretty similar. Starting the invasion from Dover would mean loading ships in sight of the Germans.
 
Also due to ULTRA we knew what they thought they knew. This is an excerpt from a report for the Prime Minister dating from May '44. It shows what the German reconnaissance had achieved and exactly what they knew.

Catalogue reference: HW 1/2784 (May 1944) in the National Archives.

DDay_Ultra_zpsis1lrmho.gif


Cheers

Steve
 
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There was a turbojet program for the V1.

A Porche design, the 109-005 and a BMW design, the P3006. Both 2 hour life disposable. The 109-005 designer was Max Mueller, who had joined from Heinkel Hirth.

The V2 required 280 man-hours to build, maybe 400 with autopilot. A BMW 003 required 700 hours, less than a piston engine, a disposable engine less again. A turbojet powered V1 would not cost much more than a pulse jet V1. German manned jet engine designs were preparing 2 hour life disposal steel turbine blades if they ran out of refractory alloys.

The V1 also known as the Fiesler Fi 103, Kirschkern (Cherrystone, its code name) was to be guided.
Standard propulsion was the Argus Reed Valve Pulse Jet. Speed was 390mph at low altitude. Improvements in the engine let experimental V1 achieve 515mph at low altitude in Feb 1945; almost impossible to intercept except for by a clipped wing Meteor III with Derwent V,ie Meteor IV. The engines that were testing late 44 would have knocked piston fighters, Meteor III P-80A out.

Control of the V1 was by a pneumatically powered gyroscopic autopilot whose course was set by magnetic compass. A propeller anemometer drove a 25:1 gearbox which turned a threaded rod that moved a nut along its length. The nut initiated switches which sequenced the flight.
A modification which allowed in flight course changes was introduced. The V1 now flew a dog leg path to prevent the use of radar plots to back track to the V1 launch site.

A radio beacon was provided in 1 in 50 launches of the V1 called Ewald I so as to track several missiles and then, having the deviations of the missiles, to adjust subsequent launches. Towards the end of the V1 campaign 1 of 2 V1s carried Ewald I suggesting that the Germans had begun to suspect the double cross system that British Intelligence used to spoof the German aim points.

The double cross system involved using double agents reporting incorrect impact data to the Germans.
For V1 impacts the wrong location was reported.
For V2 impacts the correct time but a selective location of a impact was reported.
Arado 234 equipped with timed cameras could record the impact points, although used over Europe they did not seem to be used over Britain. Erich Sommer returned in an recon Arado 234 a few years after doing so in a Ju 86. There were several ground based systems in development to track actual impact points.
The disposable turbojet allowed a longer range; increased speed and its lack of vibration did not disturb the guidance system.
Ewald I guidance couldn't alter the path of the V1 once launched. However a second generation system called Ewald 2 could.

Ewald II was designed to be jam resistant. Neither missile nor ground station emitted a signal for most of the flight. At a coordinated time the V1 would emit a coded pulse which was received by 3 ground stations. The difference in arrival times between the three stations allowed a simultaneous equation to be calculating the missile position. A course correction was then sent to the missile, which had a decoding device based on an endlessly circulating loop of magnetic tape with a high frequency bias. It couldn't be spoofed and jamming and drowning out the signal would have been difficult. The ground stations had been built. In theory this midcourse system could be used near the target for terminal accuracy. A further development was to add a system that allowed up to 5 slave V1's to follow the Ewald II guided V1.

There were two terminal homing warheads "Raddischien" or Radish for homing on the allied radar and guidance beacons (tested on a BV246 glide bomb) and MAX-P for homing on to allied microwave systems that might be used in the V1.

A V1 with turbojet, extra fuel and Ewald II guidance might have been launched against Britain from bases in Germany. The range of a radio guidance system is determined by the radar horizon: the higher one goes the further the horizon.
Willy Messerschmitt wrote to Gerhard Fieseler, congratulating him on his work, and saying that while he didn't want to interfere he would be pleased to help by sending over his engineers. The designer of the Fi 103 was Robert Lusser who had designed the Bf 109 with Willy Messerschmitt.
Willy Messerschmitt ventured that as the USA could build 4.8 million cars annually that Germany should be able to build 1.2 million V1s per year; 100,000 monthly.

(Had relations been better and Jeremy Clarkson willing 1.2 million free Volkswagens could have been sent over instead.)
The reason these weapons were called "Vergeltungs Waffen" or Reprisal Weapons and were used before the introduction of accurate guidance was the from 1941/42 the British strategy of "Area Bombardment" whose purpose was "Dehousing" and "Demoralisation". These terms are the terms used in the British policy and strategy documents.
This was new though not unexpected. Up until that time if the RAF bombed the airport at Berlin or Siemensstadt or the Luftwaffe bombed say the Docklands in London or Portsmouth which were bringing in munitions and supplies or the machine tools and engine parts factories in Coventry the target was an military target or had direct economic or military logistic consequences. The damage to nearby suburbs and housing either collateral damage or damage deemed necessary as part of taking out the targets value since housing and the occupants of the nearby housing were generally closely unavoidably associated in that activity and in housing adjacent to the walls of the factory as were the roads, rail, bridges and other infrastructure within the immediate vicinity.
Area Bombardment, as Arthur Harris plainly explained in his memoir about the targeting bombing of Lubeck, meant that no specific target was chosen, the geometric centre of the city was chosen and destroyed by concentrating in enough bombs, incendiaries in a short enough time to create a fire storm. The true meaning of the terms 'dehousing' and 'demoralisation' should be clear.

This marked a complete change, it was the British, at the urging of Lord Cherwell (Lindeman) and Churchill that first did it. These decisions were taken just as systems such as Oboe, H2S were promising to give alternatives (hence disquiet in the British camp). Those taking the anti German side will point to cities such as Rotterdam, Guernica, and Coventry but in each case there had been a specific military purpose. Rotterdam had been surrounded by German troops who had to keep moving (to get to the coast and prevent a possible British counter attack) and negotiations had gone on for 2 days while ultimatums had passed several times. No one sends in their lads to get killed in street to street fighting walking into well bunkered enemy with ambush positions without a prior bombardment. Street fighting is messy to say the least.

Coventry Ordnance Works produced 25% of Britain's aircraft, even more of its machine tools other armaments. The night bombing opperation "Moonlight Sonata" using x-geraet blind and marker bombing destroyed it and 1/3rd of Coventry's Armaments factories, damaged another 1/3rd. There were sadly about 580 dead. While every life counts and causes pain it's clear that the human cost was equal to a modern Jumbo Jet collision rather than the horror of tens of thousands dead civilians (mostly women, children old men, fighting age men were at the front) that came to be normal. Having said that, Goebbels's propaganda about Covencation didn't help.
Area bombardment didn't start the killing and bombing of civilians but it raised the number killed by two orders of magnitude. since civilians were now no longer collateral damage but the primary target itself.
Thus Germans didn't initiate a policy of Area Bombardment or even bombing of civilian industrial targets but they did initiate retaliation beginning with the Baedecker Raids after the Area Bombardment of Lubeck and Rostock. The Germans didn't initially assumed it was an attack on cultural areas. The initial V1 and V2 campaigns were area bombardment campaigns that were to be bargaining chips and eventually more accurate weapons campaigns
that could hit a a large factory.

The V2 was more costly than the V1. Whereas a V1 might cost 400 man hours to make the V2 was costed at 10,000, though it was to drop to 4000 hours per unit after the 10,000th V2. V1's would also drop, long range versions had a wooden nose cone.


V2 guidance improvements involved gyroscopes, accelerometers, better ball bearings, fluid bearings, introduction of a gimballed gyroscopic platform with lateral accelerometers and a system which used beam riding and Doppler, the "wireless canon barrel" . Both aiming for 500m accuracy.

The A4b, the winged V2, added both range and the ability to be targeted to 180m. It was to be a midcourse guidance inertial system but initially they would glide to the target area such that at 15,000m altitude the missile would do a pull up, connect with the radar signal then a final vertical dive to the target. Guidance was by three giant Wassermann radar aerials laying on the side to obtain 0.01 degree accuracy.

A workforce of 10,000 could theoretically produce 100 V2s per week whereas the same workforce producing V1s would produce 1000.
A 4 engine bomber such as a Lancaster cost 20,000 man hours. It might survive 50 missions i.e. 400 man hours per mission. A crew of 7-10 would consume between 280 to 400 hours in the week between their 50 missions just recovering, briefing and training. There would be maybe 100 man hours per mission in maintenance and as much again in provision of spare parts, ammunition, rescue services. For each mission flown there would be dozens of hours per man in training.

Hence a manned bomber mission would be costing 800 man hours not counting airfield defence, training etc, radar jamming aircraft.
 
I was on a team that restored a pulsejet for the Planes of Fame. We had 10 people researching the V-1 not including the 3 team members and we never uncovered a 515 mph V-1 of any sort.

So, I'd be interested in that if you could point me to a source that I can obtain and study. I see the 390 mph above but wartime production V-1s usually cruised more around 360 - 375 mph as far as we could uncover from German documents.

If you want to see our results, search Goolge Video for Chino Pulsejet. We also filmed one night run and it is interesting. There was no manual and it took us about a year to figure out how to start it and then another month and a half before we figured out how to get it from idle to full power. We ran it on both 87 Octane unleaded and 100 Octane unleaded. It preferred 87 Octane fuel and ran just fine. 2.2 gallons per minute at idle and 3.3 gallons per minute at full power. We only ran ours untl the internal temperature got to 1,100°F and then shut it off to save the reed pedals. That gave us about a 1.5 minute run while standing still and the temp was down by some 300°F when we ran down the runway at maybe 25 mph. Interestingly enough, the small forward speed combined with the new cowling we made increased thrust by about 25%. We had a thrust measuring setup on the test stand using a spring with a know spring constant and a linear hydraulic cylinder to get the spring compression. We calibrated it to about ±1%. The principle in that restoration was Robin Scott. Bob Velker and I helped Robin for about the last 6 months and all the duration of the time we discovered how to start and operate it.
 
Koopernic
where you got your quote? The first use of H2S was about one year (Jan 43) after area bombing decision. "Coventry Ordnance Works produced 25% of Britain's aircraft" Really? Lübeck had a port and production connected to U-boats, Rostock had a port and two aircraft factories, Arado's and Heinkel's. Was that so different from e.g. Bristol, which had a port and an a/c factory (Bristol) and was heavily bombed during 40-41 Blitz? Or didn't British have "cultural areas", only Germans? To what are you aiming at?
 
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From what I read when the (accurate) results from the transponders disagreed with the (inaccurate) on the ground reports they believed the false reports, presumed the transponders were not working and stopped using them.
Yes, which is why checking recon results with the transponders against the reports from intelligence agents would potentially expose the nature of the double agents in play. (in spite of the firm insistence that such was impossible)

That would be a far bigger and more valuable revelation than anything regarding accurate reports on V1 bombing impacts.



A Porche design, the 109-005 and a BMW design, the P3006. Both 2 hour life disposable. The 109-005 designer was Max Mueller, who had joined from Heinkel Hirth.

The V2 required 280 man-hours to build, maybe 400 with autopilot. A BMW 003 required 700 hours, less than a piston engine, a disposable engine less again. A turbojet powered V1 would not cost much more than a pulse jet V1. German manned jet engine designs were preparing 2 hour life disposal steel turbine blades if they ran out of refractory alloys.
Typo there with the V2, but otherwise very neat. I'd missed wiki's small article on the 005 until now: Porsche 109-005 - Wikipedia, the free encyclopedia
It's notable that thrust output is very similar to that of the much earlier HeS 3, granted the diameter of the latter was much greater at some 930 mm (36.6 inches) slightly smaller and a good deal lighter than the Gnome Rhone 14M. (interesting that the HeS 6 is very close to the 14M's weight and dimensions, at least from the limited information I've seen -considerably smaller than Whittle's designs, though not lighter)

I believe the 004B had managed a bit more than 1/2 the man-hours for construction than the 003's 600~700 hours (around 375 hours -50 of those going to assembly of the final unit).


Heinkel was never focused on producing a cheap, potentially disposable engine though, be it for missiles, expendible aircraft, or conventional aircraft with very high engine replacement rates. (or perhaps even not THAT high of replacement rates, but likely not of the high performance and low frontal areas and weights Heinkel was dreaming of for a cutting edge, record setting high speed fighter -look at the He 100 itself, not so big on compromise for practical applications balancing the raw speed/performance for useful producabality and flexibility -not just the exotic high speed variants, but the fact that no simple/conventional conservative alternatives were implemented in parallel on the early prototypes -like using a completely conventional cooling system)

The HeS 30 was an outstanding design that met or exceeded those lofty aspirations and made the HeS 3 and 6 look extremely poor (and the Jumo 004 not much better) by comparison. Abandoning the experimental but still very workable early designs, hoping for the HeS 30 and then rushing to develop the somewhat hacked together compromise of the HeS 8 as a drop-in replacement on the He 280 airframe conceived around the HeS 30 engine specifications.

The V1 also known as the Fiesler Fi 103, Kirschkern (Cherrystone, its code name) was to be guided.
Standard propulsion was the Argus Reed Valve Pulse Jet. Speed was 390mph at low altitude. Improvements in the engine let experimental V1 achieve 515mph at low altitude in Feb 1945
I'd not heard that at all before, either the higher thrust or higher test speed. Do you have any more specifics? That's the sort of performance gain I'd expect to see with a decent thrust augmentor (or cowling to similar effect -using ram air ducted around the hot section of the engine, deriving energy from the waste heat before being exhausted along with the combustion jet -in practice, a simpler, lighter thrust augmentor attached just aft of the exhaust nozzle is more effective at low speeds, simpler and lighter -the ram effect of a longer sleeve type duct/cowl may be more significant at higher speeds). Sleeve type ducts have the added advantage of working as heat shields around the very hot body/exhaust pipe of pulse jets. (significant for say, underwing mountings)

Simple augmenters can easily increase static thrust by 50%, so a major improvement in acceleration and speed would be likely. (they also tend to dampen vibration, noise, and visible flame)

I'd thought the Germans overlooked this mechanism, something somewhat surprising and confusing but not impossible. If they had tested alternate nozzle/exhaust, cowl, and ducting configurations, I wonder why they weren't adopted for production. Perhaps the ones they attempted were successful but relatively complex to manufacture? (other relatively simple modifications like flaring the exhaust nozzle significantly improve harmonic combustion stability and ease of starting)

Valveless Pulsejets 1.5 By Bruno Ogorelec
This is a rather fascinating article on the subject, albeit mostly focusing on valveless designs. (including one quite interesting pulse-ram jet hybrid design by Messerschmitt from the early 1970s)



The disposable turbojet allowed a longer range; increased speed and its lack of vibration did not disturb the guidance system.
Ewald I guidance couldn't alter the path of the V1 once launched. However a second generation system called Ewald 2 could.

There were two terminal homing warheads "Raddischien" or Radish for homing on the allied radar and guidance beacons (tested on a BV246 glide bomb) and MAX-P for homing on to allied microwave systems that might be used in the V1.

A V1 with turbojet, extra fuel and Ewald II guidance might have been launched against Britain from bases in Germany. The range of a radio guidance system is determined by the radar horizon: the higher one goes the further the horizon.
All very interesting, though I still wonder if improved guidance systems could have been developed earlier if the vibration/thrust/fuel consumption limitations of the pulse jet engine hadn't been a constraining factor. (plus development of a reliable, reasonably well performing pulse jet -in practice it's more an art than engineering and involves to this day a lot of trial and error rather than calculated engineering -best option with starting from scratch is to make dozens of prototypes all at once with minor to major differences across the board, some variables even chosen at random to study the behavior ... and then hope the results scale up well) Valve design was probably the most consistent, conventional mechanically engineerable component of the As 014.

Aside from that there's the question of practical use compared to similar area bombing using manned aircraft and not-quite-as-disposible engines. If nearly impossible to intercept, then the losses should be low, and bombing from relatively high altitudes and speeds with mediocre precision targeting is practical for area bombing. (while still being much more accurate than the initial V1 -and possibly operational considerably sooner) The overall cost of resources for manufacturing the expendable engines+missiles and the fuel used compared to bombs+aircraft+engines+pilots (possibly used in a single pilot fighter-bomber-like type configuration) and overall cost of materials expanded per ordinance delivered within the target area. (and desired psychological effect -would the idea of MANNED aircraft managing to invade British airspace yet be impossible to intercept be even more demoralizing? -or at least that logic appealing to German military planners)

Aside from even developing a dedicated bomber ... simply adding provisions for bombs on Heinkel's jet fighter could have been a very appealing prospect. (2500-2600 lbf of thrust from a pair of HeS 6 derived engines, wing/landing gear configured to allow the larger engines ample clearance -AND leave more room under the fuselage for bombs/drop tanks- and enough range to manage the round trip from France to Britain while also useful in fighter-interceptor configuration and in direct competition with Bf 109 and Fw 190 fighter/fighter-bomber development)

Plus, a 4-engine jet bomber could easily have engines in paired nacelles with greater strength for potential shallow dive bombing operations. (or a hypothetical 3 or 4 engine heavy fighter)

I may have to compile these ideas and move them to a separate thread, but I suppose the point here would be:
would cruise missiles be more effective than conventional jet bombers? (particularly given using less strategic materials saves little/not at all on engine manufacturing/assembly costs, only on material costs -and the metals needed for stainless steels used in Heinkel's designs were already being used in heavy quantities in piston engines of the time)



Area Bombardment, as Arthur Harris plainly explained in his memoir about the targeting bombing of Lubeck, meant that no specific target was chosen, the geometric centre of the city was chosen and destroyed by concentrating in enough bombs, incendiaries in a short enough time to create a fire storm. The true meaning of the terms 'dehousing' and 'demoralisation' should be clear.
Indeed, similar strategies to what RAF Bomber Command had formally adopted under Harris. (targeting material -civil and military, intellectual, and physical/bodily labor forces and infrastructure)
 
The He280 was intended to have the HeS8 as it's powerplants...and the ones tested and demonstrated with the HeS8 performed to all expectations. It was the HeS30 that was supposed to replace the HeS8

The RLM was actually impressed with the He280 and intended to acquire at least 300 units BUT the RLM also got involved with the engine development and insisted on development of the HeS011 instead. It was this meddling that spelled the doom of the He280 as the HeS011 was having serious development problems and cost a great deal of time when the HeS8 was nearly "bug" free and the HeS30 development was coming along behind the HeS8.
 
Koopernic
where you got your quote? The first use of H2S was about one year (Jan 43) after area bombing decision. "Coventry Ordnance Works produced 25% of Britain's aircraft" Really? Lübeck had a port and production connected to U-boats, Rostock had a port and two aircraft factories, Arado's and Heinkel's. Was that so different from e.g. Bristol, which had a port and an a/c factory (Bristol) and was heavily bombed during 40-41 Blitz? Or didn't British have "cultural areas", only Germans? To what are you aiming at?

Lubeck was a coastal city, so of course it had a port. There was a medium size slipway that repaired Baltic Sea fishing vessels. It sometimes handled repairs to smaller mine sweepers. No U-boats that I know of.

Coventry Ordinance works, I believe the correct statement should be produced parts for 25% of Britain's aircraft.

The first multicavity magnetron that the Germans got their hands on was from a December 1942 crashed Stirling near Rotterdam. The magnetron was analysed but subsequently bombed and destroyed but by then another had been captured in January 1943. Gee and Oboe (accurate to the radar horizon) were available well before this time.

The point is Lubeck's population was targeted and bombed not the slipway or the Draeger works for medical gases which also did rebreather cartridges for frogmen. the slipway wasn't specifically targeted with the nearby civilians killed as a result of collateral damage due to aiming limitations or a desire to destroy nearby transportation. The civilians themselves were as much if not more the target.

I won't go there, to justification of Area Bombardment, in accepting this policy one goes down the path of over emphasising the kind of equipment that soon precludes any other possible method. It's fine when you can get away with it with impunity but this isn't always the case. The use of orbiting aircraft to relay oboe like signals is a trivial computing problem at a time the coreolis force was factored in to artillery.

Bomber command maintained a list of legitimate targets in cities that were subjected to Area Bombardment as defence against possible war crime charges by its aviators. The only specific criminal act that would be chargeable came under an Artillery officers duty of care under the Hague conventions, he should take care not to hit civilians. Crawling artillery barrages against un evacuated towns were illegal as far as I can see and so one can extrapolate was Area bombardment.

Below a "AWACS" Vickers Wellington which might have been used to use a compass pointed aerial to provide oboe pulse signals transmissions and reception to targets area far greater than the normal radar horizon. The timing pulses would need to be corrected to allow for the movement of the aircraft around a base station but the British electronics engineers were rather good at timing circuits.

Radar2.jpg
w7.jpg
 
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I was on a team that restored a pulsejet for the Planes of Fame. We had 10 people researching the V-1 not including the 3 team members and we never uncovered a 515 mph V-1 of any sort.

So, I'd be interested in that if you could point me to a source that I can obtain and study. I see the 390 mph above but wartime production V-1s usually cruised more around 360 - 375 mph as far as we could uncover from German documents.

If you want to see our results, search Goolge Video for Chino Pulsejet. We also filmed one night run and it is interesting. There was no manual and it took us about a year to figure out how to start it and then another month and a half before we figured out how to get it from idle to full power. We ran it on both 87 Octane unleaded and 100 Octane unleaded. It preferred 87 Octane fuel and ran just fine. 2.2 gallons per minute at idle and 3.3 gallons per minute at full power. We only ran ours untl the internal temperature got to 1,100°F and then shut it off to save the reed pedals. That gave us about a 1.5 minute run while standing still and the temp was down by some 300°F when we ran down the runway at maybe 25 mph. Interestingly enough, the small forward speed combined with the new cowling we made increased thrust by about 25%. We had a thrust measuring setup on the test stand using a spring with a know spring constant and a linear hydraulic cylinder to get the spring compression. We calibrated it to about ±1%. The principle in that restoration was Robin Scott. Bob Velker and I helped Robin for about the last 6 months and all the duration of the time we discovered how to start and operate it.

Speed reached 830kmh (514.6mph) with versions that had both engine and aerodynamic refinements. One probably needs to start thinking about area ruling at 500mph. Without the aerodynamic refinements maybe 780 to 800kmh.

"The A4 (V2) and the German, Soviet and American Rocket Program"
By Claus Reuter

The A4 (V2) and the German, Russian and American Rocket Program by Claus Reuter (eBook) - Lulu
You might try Reuter, Claus Reuter for the author though C Reuter seldom works.

I obtained mine from LuLu books as a downloadble pdf.
Reuter was an engineer with the V1 and V2 program directly involved in developing V1 guidance.

The reason this tome is somewhat obscure is that a/ he is an engineer and the detail is thick at times and b/ he supports the German view point, which comes through. It is an invaluable source. Worth it just for the explanation of how a pulse jet works.

"In 1939 the German Air Ministry decided to have jet engines developed. Each of the German aero-
engine factories was asked to work on different technical solutions of this task. The Argus Motoren
Gesellschaft, Berlin, were asked to develop a pulse jet. Curiously enough, this task was formulated as
follows:

"Take a test tube, put in some drops of gasoline, shake the tube and ignite its open end. The mixture
will not burn continuously, but in rhythmic pulses."
(Don't try at home, use in laboratory environment with PPE)


v1Speed2.jpg
v1speedB.jpg
v1EwaldIIGudiance.jpg
 
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If you want to see our results, search Goolge Video for Chino Pulsejet. We also filmed one night run and it is interesting. There was no manual and it took us about a year to figure out how to start it and then another month and a half before we figured out how to get it from idle to full power. We ran it on both 87 Octane unleaded and 100 Octane unleaded. It preferred 87 Octane fuel and ran just fine. 2.2 gallons per minute at idle and 3.3 gallons per minute at full power. We only ran ours untl the internal temperature got to 1,100°F and then shut it off to save the reed pedals. That gave us about a 1.5 minute run while standing still and the temp was down by some 300°F when we ran down the runway at maybe 25 mph. Interestingly enough, the small forward speed combined with the new cowling we made increased thrust by about 25%. We had a thrust measuring setup on the test stand using a spring with a know spring constant and a linear hydraulic cylinder to get the spring compression. We calibrated it to about ±1%. The principle in that restoration was Robin Scott. Bob Velker and I helped Robin for about the last 6 months and all the duration of the time we discovered how to start and operate it.
Neat! I'd seen the Chino pulse jet demonstrations before, but hadn't realized the nature of the cowling.

This video in particular shows it well:
View: https://www.youtube.com/watch?v=WCsKs2NhdWg
It appears to be similar to typical NACA cowlings used on radial engines.

Any idea if propane was tried during early test-start-ups? (liquid fuel starting can be really problematic ... propane seems to be the go-to fuel for easy starting and test-runs before things are smoothed out -or as a starting fuel, and MUCH safer than the acetylene Germans used)

The paler flame (and slightly bluish tinged orange flame in the night video) seems to point towards leaner/more complete combustion than a lot of other V-1 tests and similarly sized pulse jet designs.


Aside from that, I do wonder if using an even longer cowling that shrouds the entire exhaust pipe (or particularly one extending beyond the exhaust nozzle -acting a venturi to draw air through the cowl/duct even when static) would be even more effective in improving thrust.

I mused on it in much greater detail in my previous post, but seeing the Chino jet in action, I can pretty easily say the concept is basically that sort of cowl combined with the simple thrust augmentor explained here:
View: https://www.youtube.com/watch?v=Ab5DU15O9s8
This design seems to use a cowl/duct extending all the way to the exhaust nozzle, but it ends short of the exhaust nozzle itself. I'm not entirely sure why.

In fact, I'm now wondering if the As 044 wasn't just a scaled up 014, but derived its added thrust from improved cowling/ducting design instead. (which implies superior fuel consumption as well) And perhaps it's the 044 that was tested on the faster V-1 variant?





It's interesting to note (and I only just discovered this when searching for some of these relevant pulse jet articles that Boeing is currently developing an embedded cowl/duct augmented valveless pulse jet engine rather seriously.

View: https://www.youtube.com/watch?v=chmmUF9fPSE

Not sure if there's any particular recent advancements that favor this, the basic concept (with or without valves) seems kind of obvious to at least experiment with. If that video's accurate, they also seem to be using the cup type valveless arrangement (I'd have thought the pulse/ram jet transition arrangement would be preferable -also has merits when used purely for pulse configuration, but I'm sure they have reasons -I assume Messerschmitt's patents on that type would have long since lapsed at this point too).


On the general topic of pulse jet efficiency:

View: https://www.youtube.com/watch?v=b0KJwa5iWTY


View: https://www.youtube.com/watch?v=rbn8qvjjAW4

Though a lot of the hobby jets are simplified by using propane as fuel, or easily vaporizing and smokeless fuels like methanol. (or sometimes methanol/nitromethane blends, similar to small two-stroke glow-plug engines)




The He280 was intended to have the HeS8 as it's powerplants...and the ones tested and demonstrated with the HeS8 performed to all expectations. It was the HeS30 that was supposed to replace the HeS8
See my reply here: http://www.ww2aircraft.net/forum/av...s-ww2-jets-39511-post1200914.html#post1200914
 
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The Anthony Kay book on German Jet engines provides some information on inductor ramjets which could achieve a static thrust. The liquid fuel was heated to high pressure and injected by a nozzle, this induced airflow which brought in air. At some point you used the ramjet tube itself to heat heat the fuel. It was rather hard to control the temperature of the fuel. Propane as a fuel made sense in that the V1 used compressed air to pressurise the main fuel tank and to blow fuel into the engine. Why not used propane, which was available as a by-product of the synthetic oil plants. Compressed air was used to spin the gyros of the V1's guidance system as well as operate its flight surfaces. If there was a battery needed, it provided minimal power.
 
Lubeck was a coastal city, so of course it had a port. There was a medium size slipway that repaired Baltic Sea fishing vessels. It sometimes handled repairs to smaller mine sweepers. No U-boats that I know of.

Coventry Ordinance works, I believe the correct statement should be produced parts for 25% of Britain's aircraft.

In fact I doubt even that, IMHO COW during WWII produced mostly large gun turret mountings for the navy, too heavy stuff for a/c.

The first multicavity magnetron that the Germans got their hands on was from a December 1942 crashed Stirling near Rotterdam. The magnetron was analysed but subsequently bombed and destroyed but by then another had been captured in January 1943. Gee and Oboe (accurate to the radar horizon) were available well before this time.

AFIK the Rotterdam Gerat (H2S ground-mapping radar)was salvaged from a Stirling which crashed near Rotterdam on 2 Feb 43

The point is Lubeck's population was targeted and bombed not the slipway or the Draeger works for medical gases which also did rebreather cartridges for frogmen. the slipway wasn't specifically targeted with the nearby civilians killed as a result of collateral damage due to aiming limitations or a desire to destroy nearby transportation. The civilians themselves were as much if not more the target.

Was that in practice much different from targeting Bristol harbour, which didn't have any strategic significance in 40s (Avonmouth and Portishead had, but they were seen as separate targets by the LW), which was straight in the middle of a historical city, surely a "cultural area" if Bristol would have been a German city. In fact the 4 first Blitz raids against Bristol killed 600 civilians, the 4 raids against Rostock killed 204. In Lübeck 312 or 320 died, the highest casualty figure for the first four Bristol raids was 200.


Bomber command maintained a list of legitimate targets in cities that were subjected to Area Bombardment as defence against possible war crime charges by its aviators.

How it was that British thought that the LW used the same ruse during 40-41 Blitz



Below a "AWACS" Vickers Wellington which might have been used to use a compass pointed aerial to provide oboe pulse signals transmissions and reception to targets area far greater than the normal radar horizon. The timing pulses would need to be corrected to allow for the movement of the aircraft around a base station but the British electronics engineers were rather good at timing circuits.

IIRC AWACS Wimpys were used in 1945, a bit later than Lübeck and Rostock attacks
 
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There's some serious BS regarding bombing above. The British did target cities and not specific targets in area raids. Harris is on record as saying acreage destroyed was more important than individual factories etc.

The German raids of the Coventry type were also area raids, attempts to burn the city rather than destroy specific targets, whatever they may have produced. The crucial clue is in the make up of the ordnance dropped by the bombers. A high percentage of incendiary almost always equated to an area raid (or area type raid as the USAAF coyly called them)

The reason that the Luftwaffe did not create a firestorm, which is a particular physical phenomenon, is because they only managed one of the two most important criteria to achieve this. Bombing has to be concentrated in space and time. The Luftwaffe could certainly concentrate their bombing in space but they were 'shuttle bombing'. The aircraft employed carried relatively light loads and returned to bases in France to re-arm before returning. The bombing of Coventry took hours. By contrast the initial 5 Group raid on Dresden, which created the firestorm, took only 25 minutes to drop 881 tons of ordnance (43% by weight incendiary)
It was not for want of trying that the Luftwaffe failed to create the kind of devastation Bomber Command later would. It was for lack of suitable aircraft and enough of them.

The first loss of a Gee equipped aircraft was 12/13 August 1941 when one of the trial Wellingtons was lost over Hannover. This was seriously bad luck as the first trial had only been on the previous night. The first raid generally considered to be the first 'Gee led' raid was that on Cologne on 13/14 March 1942.

First operational trial of Oboe was a raid on Brest on 7/8 December 1941. Stirlings of Nos. 7 and 15 Squadrons carried the new system. I don't know when the first set was lost.

Cheers

Steve
 
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Yes, which is why checking recon results with the transponders against the reports from intelligence agents would potentially expose the nature of the double agents in play. (in spite of the firm insistence that such was impossible)

That would be a far bigger and more valuable revelation than anything regarding accurate reports on V1 bombing impacts.

That is correct except that whenever any investigation was performed the Germans preferred not to believe the unbelievable, enigma couldnt be broken and so it wasnt and all german agents couldnt be turned so they werent. In terms of all the evidence going one way a few bomb craters would not prove or dis prove anything. The Germans had ample evidence that their codes were being broken and that their agents had been turned, they chose to ignore all of it.
To me the only possible effect on the war the V1 could have had would be bombarding the beachhead at Normandy. Reading here the intense activity being done to launch V1s from Aircraft as the allies were overrunning the launch sites shows a sort of collective detachment from reality.
 
Hi KoolKitty,

If they made the missile a lot larger, it would then be about the size of a manned aircraft. That would mean it would probably slow down unless it was very carefully designed and powered. The faster piston planes were using a Daimler-Benz engine (or radial) that cost an order of magnitude more to produce than a pulsejet. So ... while the guidance options might have been more, I doubt: 1) they could have afforded the 1-way engines and 2) that the number "new larger V-1s" that got through would be nearly as many as the smaller, faster, real V-1s that really did get through.

I have never yet seen a "what if" that could be answered to the satisfaction of most. It's probably better to deal with the real V-1 and investigate alternative electronics than to redesign the missile. However, you'd have to know what was available and when to make an eductaed alternative proposition. I'm an electrical engineer and I know the technology, but not exactly when it was made available since it was all there when I started college (in a different discipline to start with) as well as a host of digital devices that would have been great for the WWII purposes but weren't yet invented during WWII.

Going back to when we restored a pulsejet, the breadth of what they knew was impressive, but we weren't really sure exactly what was available to them ... all we got the was design documents of what they actually produced. Those documents did not include alternative guidance solutions from the time. So I think that without detailed knowldge of exactly what techologies they had it would be extremely difficult to second-guess the German engineers of the time ... at least for me to do it.

We know they had no GPS and no digital devices. They DID use a vane amemometer (the little prop on the fornt) to measure time / distance. I'm thinking, but not concluding, that they did the best they could with what they had at the time. I'm not too sure how it could have been made more accurate simulaneously with still being autonomous.

With all the fighters patroling and shooting down all the V-1s they could, I'd think a pathfinder plane to drop transmitters would have had a very low survival probability, but I could be wrong there. I'd hate to try to punch through the lines of defending Spitfires, Tempests, and Typhoons, P-51s, etc. that were intent on shooting down V-1s. If the pathfinder didn't make it, then the surviving V-1s would ALL miss or would revert to the existing guidance system. If they all missed it would be a monumental waste for Germany and if they used the default guidance, then who would volunteer to commit virtual suicide to make them slightly more accurate?

So I'll decline to speculate what they might have done better. I really like that fact that they managed to get it to fly a dogleg to try and hide the lunch site. That alone says a lot about the clever thinking that went into the V-1.

So, you might be right above, but I won't try to conclude anything about alternative V-1 designs. If I had to design one now, it would be a lot better, but I have a few years of technology from which to draw that they didn't have. Even brushless servo motors would have been a big step forward.
 
We seem to be concentrating on the higher speed of the V1s making them harder to intercept by aircraft.
I've got to agree on that.
But weren't most of the V1s brought down, destroyed by antiaircraft fire ?
How much difference would the extra speed mean to the effectiveness of the proximity fuses of the AA ?

But did the Germans know what was bringing down most of their V1s ?
 

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