Ta152H1 high altitude speed

Discussion in 'Flight Test Data' started by TempestMKV, Dec 24, 2008.

  1. TempestMKV

    TempestMKV Member

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    At 10000 meters, ie 33000feet, Ta152H1(with GM1) engine output should be around 1740 HP, max speed should be about 470-475m/h.

    On the other hand, P47M R2800-57 output @ 10000m/33000feet is nearly 2800HP while maxspeed is 473m/h.

    Anyone can explain how could Ta152 achieve same max speed with 1000HP smaller than P47M? Martian technology?

    Furthermore, at 30000 feet/ 9000m:

    P47M max. speed 469km/h 2800HP
    Ta152 max. speed 465km/h 1400HP- with MW50, without GM1

    2800HP vs 1400HP, same speed. Why?
    [​IMG]
     

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  2. TempestMKV

    TempestMKV Member

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    As water-cooled engine, 21lbs spitfire XIV output is 2050HP @SL just same as Ta152 @SL. 21lsb Spitfire XIV is slightly faster than Ta152 @SL.

    At 9000m, both Ta152 with MW50 and spitfire XIV outputs are 1400HP or so. However, Spitfire XIV max speed is 443m/h while Ta152 is 465m/h!


    Great Martian technology of Ta152!
     
  3. HoHun

    HoHun Active Member

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    Hi Tempest,

    >Anyone can explain how could Ta152 achieve same max speed with 1000HP smaller than P47M? Martian technology?

    Exhaust thrust.

    Regards,

    Henning (HoHun)
     
  4. kool kitty89

    kool kitty89 Well-Known Member

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    Not to mention they were completely different aircraft with different drag characteristics, the Ta 152 being roughly 4,000 lbs lighter and with a much grater frontal area.

    If you look at the P-47 alone, compare the P-47M to the XP-47J. The XP-47J was a bit lighter, but not hugely, it used the same engine and airframe, and similar propeller but managed 507 mph in testing at 34,300 ft. The key difference? The XP-47J utilized a tight fitting, streamlined engine cowling with a large, conical spinner with a cooling fan. This dramaticly reduced the aircraft's parasitic drag. (similar cowlings were used by the Fw 190A, pretty much all BMW 801 installations, the Hawker Tempest II and Sea Fury, the J2M Raiden, several prototypes in the US, and I beleive the Soviet La-5/7)
     
  5. delcyros

    delcyros Well-Known Member

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    Hi TempestMKV,

    You encountered a systematic error in Your data´s for the P-47M. Your data´s show no engine output difference at allfrom 0 to 5000 to 32000ft for the R-2800-57. This is likely the cause for the difference. I may be wrong but can´t imagine any piston engine to have no change in poweroutput at altitude this way or another.
    Just as a pointer to check that aspect, hope this helps,
    Delc
     
  6. Kurfürst

    Kurfürst Banned

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    I guess long span wings, and having an inline engine in an airframe strongly resambling a fighter instead of a locomotive with an enormous radial also helps. 8)
     
  7. Kurfürst

    Kurfürst Banned

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    Its normal, the curve is like this because the P-47's turbocharger - it doesn't take any power to run from the engine itself, so no increasing supercharger power requirements with altitude. The downside is as HoHun noted, lack of thrust gained from exhaust, and the bulk of the turbo system.
     
  8. runningdog

    runningdog Member

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    Aeroplanes is aeroplanes, they don't always do what you expect them too, a bit like folk I suppose...........
     
  9. Njaco

    Njaco The Pop-Tart Whisperer
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    :)

    Thats it right there!!!
     
  10. TempestMKV

    TempestMKV Member

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    That makes sense.
    BTW, anyone can provide Griffon65's output above 9000m?
     
  11. kool kitty89

    kool kitty89 Well-Known Member

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    Another good example is comparing planes like the P-51 and P-38, P-51H to P-47M, or He 162 to the Me 262, the Me 262 has roughly double the thrust but is also much larger, while the performance is fairly similar. (the He 162 actually faster with the emergency overrev of the BMW 003E)

    The P-51H's case is particularly good as it's fairly comparable in size to the Ta 152 (though closer to the 190), but a bit lighter and with smaller wings and no cockpit pressurization. (the Fw 190D-11/13 with the same engine as the Ta 152 -minus the GM-1 would be very comperable to the P-51H and still much different than the P-47)

    Again, they're just different aircraft with different characteristics.
     
  12. TempestMKV

    TempestMKV Member

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    .....I am intersted in "Spitfire XIV HF with critical height=30000feet, plus liquid oxygen" which is possible in history.
     
  13. TempestMKV

    TempestMKV Member

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    This is the output chart of Ta152H1(Jumo213E) and 21lbs spitfire XIV(Griffon65).

    The pink line is of SpitfireXIV; and red line is supplementary of output with Gm1. There are 3 flow rates of Gm1, so 3 lines; the blue line indicates the Ta152 output if the 3rd speed is broken which sometimes occurs. LOL


    As we can see, at sea level, spit and Ta152 share same engine output and same max. speed, however, at 30000 feet, Ta152H is 35km/h faster than spitfireXIV while spitfire's output is greater. So the Ta152's max speed of [email protected] is quite suspicious. I prefer that's the result of Gm1 or under no weapon condition.

    BTW, it's no use of turning on MW50 above 7k altitude.The max. speed with MW50 at 9000m is just ridiculous.

    Jumo213E's 2-stage 3-speed supercharger shares same performance with Griffon's 2-stage 2-speed......

    If Britain brought out Spitfire XIV HF or liquid oxygen, the GM1 would be overcome above 10k meters, what a bad news for Ta152!

    Above10k, 17min GM1 operating is Ta152H1's only hope; below 10k, both Ta152 and Dora are outperformanced by 21lbs boost Spitfire XIV.
     

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  14. HoHun

    HoHun Active Member

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    Hi Tempest,

    >As we can see, at sea level, spit and Ta152 share same engine output and same max. speed, however, at 30000 feet, Ta152H is 35km/h faster than spitfireXIV while spitfire's output is greater. So the Ta152's max speed of [email protected] is quite suspicious.

    Exhaust thrust.

    As long as you don't understand that, all your assertions are just nonsense.

    Regards,

    Henning (HoHun)
     
  15. TempestMKV

    TempestMKV Member

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    Then tell me why Exhaust thrust can't help Ta152H1 at seal level?

    Does Spitfire XIV have no Exhaust thrust?

    Furthermore, I'll amend my opinion, Let's see this chart.

    The A, B, C points stand for the three FTH (full throttle height) where pilot push 100% throtle and just get max boost pressure.

    The red lines indicate the Jumo213E engine is on Max. boost, so between 8k-10k meters, Jumo213E in on Max. boost with MW50, and below 11k meters, pilots dare not turn on GM1,otherwise, the boost exceeds enigine's ability ...

    Conclusion: at 32500feet/9848m ,no GM1 turning on, Jumo213E can NOT acheive 1740HP.
     

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  16. delcyros

    delcyros Well-Known Member

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    Kurfürst, thanks for the hint. I stand corrected about the crit altitude performance. Just still think that it´s worth to see an actual poweroutput graph for the R-2800-57 with boost levels involved.

    "There are reports that XP-47J actually attained 507 mph at an altitude of 34,300 feet. 2,800 hp is 133% of rated power. At military power (100%), the XP-47J could sustain 470 mph. 435 mph was attained at 81% of its rated power (1,700 hp). All performance figures were obtained at 34,300 feet."

    That sounds comparable to me: 2100 hp @ 34.3000ft giving 470 mp/h on the XP-47J while
    2.100 hp(GM-1, at Kampf- u. Steigleistung) @ 38.000ft, giving 462 mp/h on the Ta-152H

    It´s possibly not perfectly comparable as the considitions are unknown but it appears to be indicative for beeing in general congruence. You should ask the question what happened to the P-47M that it´s performance was reduced so appreciably?
     
  17. Kurfürst

    Kurfürst Banned

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    I don't really think so, you seem to be comparing the Griffon 65's output with 400 mph of ram - which will push the curve to the right, ie. like having a higher rated altitude - while the the Jumo 213E power curve is static (0 mph).

    Apples and oranges...
     
  18. HoHun

    HoHun Active Member

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    Hi Tempest,

    >Then tell me why Exhaust thrust can't help Ta152H1 at seal level?

    I'm not going to ram down knowledge down the throat of a struggling loudmouth who already has his mind made up. My time is too precious for that.

    If you seriously want to learn, ponder the question what is different between an engine at its full throttle height and an engine way above its full throttle height, even if the two have the same shaft power at that height ...

    Regards,

    Henning (HoHun)
     
  19. DerAdlerIstGelandet

    DerAdlerIstGelandet Der Crew Chief
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    Keep the thread civil people...
     
  20. mad_max

    mad_max Member

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    Anyone here think about the density of air at 30-35-40k affecting drag characteristics?

    Engine volume and the engines efficiency at various alts. will also play a roll.

    As for exhaust thrust the Jumo will have more than the turbo Pratt, but the Jug still has exhaust thrust.

    Also at those high speeds the instruments of the days were questionable. Even
    the position of the pitot tube could add or subtract speed. Just look at the Navy study
    between the F4U and the Hellcat. Ended up both had basically the same speeds.
     
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