Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
All other things being equal (eg geometry, mass density) the vibrational frequency is a function of the modulus of elasticity. That's only about 10% different for mild steel and stainless. The harmonics shouldn't be an important issue.Neat info there, but not so relevant to the 004A. Those didn't make use of just standard Krupp stainless steel alloys but specialized high temperature alloys containing significant amounts of even more scarce metals like cobalt and molybdenum. (the latter is exceptionally good at increasing creep strength)
So Jumo 004Bs might have been able to be built without resorting to mild steel, but they'd likely still have had problems with turbine vibrations (due to differing harmonics in the alloys used) as well as air cooling of the turbine blades. (vibration issues were more serious in terms of preventing mass production, otherwise the early 004B variants using solid cromadur -krupp stainless steel- blades with air cooling jets/channels at the hub alone could have been in production much earlier)
Even if the Luftwaffe had 1,000 Me262s fully equipped with all the fuel they needed, endless ammo supply, all the qualified pilots to fly them and an endless supply of parts, the Allies still would have overwhelmed them with the 1,000 plus bomber stream and hundreds of fighters on escort rotation and the rest on CAP missions....That would have been more than adequate to destroy the USAAF bomber force even if only half could get into the air at any given time?
Even if the Luftwaffe had 1,000 Me262s fully equipped with all the fuel they needed, endless ammo supply, all the qualified pilots to fly them and an endless supply of parts, the Allies still would have overwhelmed them with the 1,000 plus bomber stream and hundreds of fighters on escort rotation and the rest on CAP missions.
And this was each day...
You are not factoring in attrition.The Me 262s took out something like 500 Allied aircraft,mostly USAAF bombers. If the LW was able to get an average 200 (six times actual) 262s in the air each day, we could expect the USAAF to lose in the order of 2000+. With that sort of attrition rate they would have packed up and go home:
"...Meanwhile, the losses to the bomb groups continued unabated. During the week prior to Black Thursday, the Eighth Air Force lost nearly 90 bombers on three missions. It was obvious to everyone, including the Germans, that not even America's vast resources could sustain such losses indefinitely."
"As expected, bomber crew morale began to falter as the losses piled up. The situation was aggravated somewhat by the Luftwaffe tactic of targeting one particular bomb group for heavy losses or, if possible, extinction, The 100th Bomb Group (BG) earned the nickname 'Bloody 100th' after it lost 12 out of 13 aircraft following an October 10 Munster mission, while the 492nd BG, a B-24 outfit, was nearly wiped out after becoming a 'marked group' the following year."
"Joseph W. Baggs, 384th BG lead bombardier, recalled that as early as August only eight of the group's original crews were left. Four days before Mission 115, the 381st BG's medical officer wrote that 'morale is the lowest that has yet been observed...'
World War II: Eighth Air Force Raid on Schweinfurt | HistoryNet
Also if Germany had not tried to pursue the counterproductive V2 project (see previous posts), much more resources would have been available for fighters. More 262s would have meant fewer 88mm flak guns required and hence release for anti tank duty. (10,000 were dedicated to anti aircraft duty).
The vicious circle would arguably been broken, and with it Allied air superiority.
The Me 262s took out something like 500 Allied aircraft,mostly USAAF bombers..
The Me 262s took out something like 500 Allied aircraft,mostly USAAF bombers. If the LW was able to get an average 200 (six times actual) 262s in the air each day, we could expect the USAAF to lose in the order of 2000+. With that sort of attrition rate they would have packed up and go home:
"...Meanwhile, the losses to the bomb groups continued unabated. During the week prior to Black Thursday, the Eighth Air Force lost nearly 90 bombers on three missions. It was obvious to everyone, including the Germans, that not even America's vast resources could sustain such losses indefinitely."
"As expected, bomber crew morale began to falter as the losses piled up. The situation was aggravated somewhat by the Luftwaffe tactic of targeting one particular bomb group for heavy losses or, if possible, extinction, The 100th Bomb Group (BG) earned the nickname 'Bloody 100th' after it lost 12 out of 13 aircraft following an October 10 Munster mission, while the 492nd BG, a B-24 outfit, was nearly wiped out after becoming a 'marked group' the following year."
"Joseph W. Baggs, 384th BG lead bombardier, recalled that as early as August only eight of the group's original crews were left. Four days before Mission 115, the 381st BG's medical officer wrote that 'morale is the lowest that has yet been observed...'
World War II: Eighth Air Force Raid on Schweinfurt | HistoryNet
Also if Germany had not tried to pursue the counterproductive V2 project (see previous posts), much more resources would have been available for fighters. More 262s would have meant fewer 88mm flak guns required and hence release for anti tank duty. (10,000 were dedicated to anti aircraft duty).
The vicious circle would arguably been broken, and with it Allied air superiority.
...
Some perspective on the numbers.
The first allied aircraft was shot down by an Me 262 in July 1944, the last on 8th May 1945, a total of 10 months for the 445 claims.
In July and August 1944, just 2 months, German flak shot down more 8th and 15th AF aircraft (475) than the Me 262 did in its entire 10 months of operations.
The Me 262 was no more a game changing, war winning, weapon than the 8.8cm flak cannon was.
Quality wasn't the issue (the decline in quality was more due to worsening war conditions than anything) it was sheer time/engineering resources to get functional engines into mass production. In 1942 it SEEMED like the 004 was nearing mass production, but a bunch of unexpected problems came from resonance issues when using different materials (the thermal and mechanical stress issues with using mild steel and stainless steel in the construction without rare/proprietary turbine alloys -and LOTS more stainless steel for the combustion chambers and such, were all expected, it was the vibration issues that caught them off guard).All other things being equal (eg geometry, mass density) the vibrational frequency is a function of the modulus of elasticity. That's only about 10% different for mild steel and stainless. The harmonics shouldn't be an important issue.
...The dominant factor in preventing quality engines was the inadequate supply of nickel and to a lesser extent chromium; design issues were definitely there such as poor fuel control (leading to overheats and flameouts) but it's hard to blame the engines lack of refinement since the overheats due to fuel overdosing could have been tolerated with better alloys. A vast engineering effort went into reducing the nickel requirements of the engine down to about 6.0 kg/unit. On its own this distracted much talent away from the basics. The pioneer in jet engines in Germany and effectively the world was Heinkel and one reason they failed to get orders was that they were not as far down the path of reducing nickel consumption as the other manufacturers.In retrospect, rather than building around 1400 poor-quality machines, they should have limited production to 500 high-quality units.
A case in point is the combustion chamber cans. There were six of these arranged as a ring around the shaft, they were initially made of a heat and corrosion resistant high nickel and chromium content austenitic alloys (basically a fancy stainless steel). In order to reduce demand for these metals the cans were made out of ordinary carbon steel with an aluminium oxide coating (effectively ceramics). Thus these can needed to be replaced at least every 25 hours. In fact the cans often burned through. Even eliminating the nickel but retaining the chromium would have improved this enormously. Another case in point is the translating exhaust cone which was also of ordinary steel and distorted under heat and stress to block the engine.
Re: Me 262 Mythology
That would have been more than adequate to destroy the USAAF bomber force even if only half could get into the air at any given time?
I may have mentioned it before, but the Me262s weren't warmed up on the ramp, they were towed out to the line by a vehicle and started as their turn came in the que, having just enough spin-time to get the engines up to temp before T/O.
I may have mentioned it before, but the Me262s weren't warmed up on the ramp, they were towed out to the line by a vehicle and started as their turn came in the que, having just enough spin-time to get the engines up to temp before T/O.
Was that to save fuel or engine life.
For fuel conservationWas that to save fuel or engine life.
When the engines start, you have to watch the pyrometers (exhaust temp) stabilize and then bring the engine RPMs up to level.In many if not most turbine engines, there is little "warm-up" time needed unlike a recip. Cool down during shut down - different story.
This is from Zeno - the POH developed by the AAF for captured Me 262 operation. Although there is a paragraph about "warm up" and ground test, there is no specific warm up parameter, the only requirement was ensuring the exhaust temp didn't exceed 650 C.
http://zenoswarbirdvideos.com/Images/Me262/262PilotHandbook.pdf