German 'jet program' - how to do it?

[tomo pauk]

Depending on what one reads, there will be a list of issues/problems that prevented Germans from extracting the most from their early lead in the field of jet propulsion in ww2. What changes would've made their jet technology have a stronger effect on air war in Europe, if not the world? How to plug the gaps, matterial-wise? Any missed opportunities with regard to engines themselves? More emphasis to radial compressors vs. axial compressors? The best way to employ these engines? What the Allies can do against the greater threat?
I certainly don't expect German victory here, just curious about technical and operational consequences.

(hopefully we can move away from trumpeting the He 280)

 

[Capt. Vick]

Don't go to war, dominate the jet market...BE NICE TO EVERYONE!

 

[tomo pauk]

Unfortunately, the ww2 still unfolds, Jeff.

What Germany will need by ~1943 are: fighter, night fighter, bomber (attack aircraft still have a lot of mileage with piston engines, even if the jet engines do offer interesting possibilities).
Fighter - needs to offer a substantial performance increase not just against the current German fighters, but more importantly the current and perspective Allied fighters. A counter against fast & high flying recons is also needed.
NF - again the substantial performance jump is needed, especially once Germans are aware of Mosquito's abilities (both as a bomber and as a NF).
Bomber - actual materialization of Schnellbomber concept.

 

[Shortround6]

I think the main problem/s with the engines themselves were the turbine section and the burner cans.
The is a lot of ink about the different compressors but if the turbine blades crap out in 10-15 hrs the compressors are not the operational problem.
Like wise if the burner cans cannot maintain a stable flame front or burn through quickly the compressors are a side arguement

Large use of jets without significant increase in reliability/durability may not give a big increase in force effectiveness due to maintenance problems.

Best best for use would be day fighter and recon. Germans were getting deficient in recon. You cannot bomb what you don't is there and the Germans can't build enough jet bombers to make a real difference in any case. Even Tactical.

 

[tomo pauk]

Good call on the need for recon A/C, and short life of turbines (though methinks the engine life was 25 hrs in 1944?). Perhaps it migh've make sense to (re)design engines so they have disposable turbines, to be changed after 20 hrs, before the air-cooled turbine blades can be mass manufactured?

Otherwise, going on with jet engines entails a number of advantages and shortcomings. Apart from enabling performance superior to piston engine, jet propulsion does not require prop (saves on production time & resources, no problems with guns' choice, no added weight), no cooling system (means less weight & complexity), does not require hi-octane fuel nor ADI - even diesel will do. There is no torque reaction, while operation of jet engine is far simpler than that of piston engine & prop (makes a lot of difference for the low-time pilots). In words of British pilot, from Wikipedia:

"The main impressions of my first jet-propelled flight were first of the simplicity of operation. The throttle was the only engine control; there were no mixture or propeller levers, supercharger or cooling-gill controls and the fuel system had simply one low-pressure valve between the tank and the engine pump, and one high-pressure valve between the pump and the engine. There was no electric booster pump. Secondly the absence of vibration or the sensation of effort being transmitted to the pilot's seat was outstanding."

Disadvantages include the aforementioned low turbine life, need to 'nurse' the throttle, high fuel consumption that was further emphasized by fast that German jet aircraft were two-engined (Me 262 carried six times more fuel than Bf 109, or about two times as much as early P-38 or P-47D).

So my 1st actual suggestion is that Luftwaffe needs an 1-engined fighter - engine overhauls & swaps will be far more economical, and fuel consumption in day-to-day operations will not go through roof.

 

[pbehn]

The metallurgy and the ins and outs of WW2 jet design are way above my pay grade but as I understand it much politics were involved. Germany would be short of metals like nickel but not so short that they didn't exist, they just didn't have the highest priority needed. A jet engine wasn't going to win the war in the east.

 

[tomo pauk]

There was a suggested Fw 190 version with jet engine (type of engine unknown to me). Note the additional fuel tank between the engine and cockpit, fuel consumption was expected to be several times greater than of the BMW 801. Calculated top speed is above 800 km/h. From here.

The 'Jetfire' - Spitfire converted to jet power - what-if model is shown here (far better looking than the 'Jet-190').

 

[tomo pauk]

By mid/late war, Germans tried to incorporate more and more of materials that were easy to come by - steel, wood - in aircraft construction. Wood was used for wings of the Me 163, while people at Blohm & Voss criticized the Heinkel future He 162 for staying with 'classic' materials for most of the weight of airframe. The airframe of their straight-wing proposal P.211.02 was to be made, weight-vise, of 58% steel, 23% wood, and just 16% of 'light metal' (aluminium derivatives). Main bearing item was supposed to be made of two steel tubes (front/lower one doubling also as air intake for engine, the aft/upper doubling as fuel tank, and connected tail with rest of the aircraft), connected with 3rd sheet steel item. Thickness of steel was 1-2mm, depending on part. Wing was partially steel, partially wood. Main undercarriage was adopted from Bf 109. But, like all German jet aircraft, it was too late, only the steel part of fuselage was seem to be produced.
Against the jet conversion of the Fw 190, the 'proper' jets will have tricycle U/C (= better visibility for take-off; less problems for new pilots?).
Article about the P.211.02: link.

The jet 'version' of the Me 163 was proposed by Lippisch (who was also instrumental in making the Me 163 possible) - wiki.

Layout of the B&V P.211.02 (stahl = steel; holz = wood):

 

[tomo pauk]

Something I've bashed not a long time ago - fuselage from He 162, wings from Me 163. Call it MeH 162.5
(original He 162 for comparison to the right)

 

[Capt. Vick]

Hollow turbine blades, manufactured individually, each keyed to fit into the spinning hub.

 

[GrauGeist]

*IF* the RLM actually realized what Heinkel was showing them in August of 1939, when the He178 was being deminstrated to them, and backed the jet program (across the board) as a priority, then many of the late-war engine issues as well as airframe material supplies could have been resolved earlier, not when the program became a priority out of desperation.

 

[SaparotRob]

*IF* the RLM actually realized what Heinkel was showing them in August of 1939, when the He178 was being deminstrated to them, and backed the jet program (across the board) as a priority, then many of the late-war engine issues as well as airframe material supplies could have been resolved earlier, not when the program became a priority out of desperation.

What he said.

 

[Graeme]

*IF* the RLM actually realized what Heinkel was showing them in August of 1939, when the He178 was being deminstrated to them, and backed the jet program (across the board) as a priority, then many of the late-war engine issues as well as airframe material supplies could have been resolved earlier, not when the program became a priority out of desperation.

At the end of the day, I'm glad they were ignorant of the potentials - for the Allies sake.

 

[SaparotRob]

Ya' got that right!

 

[GrauGeist]

At the end of the day, I'm glad they were ignorant of the potentials - for the Allies sake.

I agree - although it would have made the Allies up their game in the way of jet development.

And we has some really cool ones in the works, too.

 

[tomo pauk]

And we has some really cool ones in the works, too.

And some real clunkers...

 

[GrauGeist]

And some real clunkers...

Yes indeed.

Along those lines, the P-59 was a sad tale of over-zealous secrecy, leading to errors and frustration.
The fact that it flew before the Me262 is impressive.

 

[GTX]

Something I did over a decade ago based on this sort of idea: A Simple Issue of Metals

 

[Acheron]

My two cents on the subject:
1st AFAIK, the jet engines could fly with considerable lower-quality fuels, while piston-engines, at least for high-performance fighters, required highly-refined fuels. IMHO a considerable issue for late war Germany.
2nd if Germany goes for jet fighters early enough to make an impact on the war, it will most likely be early enough for an allied counter-development to materialize. The amount of resources, including technical expertise, the US could throw at problems was incredible.

 

[Dimlee]

If all efforts are focused on Ar 234 alone since 1941-1942 and other programs are shut down in infancy, will it help the Luftwaffe in the long run? One base type in several variants: recon, fighter, bomber. I remember that Ar 234 did not excel as a night fighter but probably longer training would help?
Full disclosure: I'm somewhat "addicted" to this aircraft.