Ta152H1 high altitude speed

[TempestMKV]

I've made a mistake.

See this chart, on pink lines, boost is same. It's unwise to achieve high boost(such as 1.8-1.9ata) at 8km-10km because supercharger will eat lots of engine output.

So MW50 can NOT give Jumo213E more power than 1340PS between 8km-10km.

This issue is very simple:

Could MW50 and GM1 be turned on simultaneously?

If yes, Jumo213e output @9.8km=1700HP

If no, Jumo213e output@9.8km=1320HP , GM1 only available above 11km.

 

[TempestMKV]

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)

With 1320HP @ 9.8km,Ta152H1 is 35km/h faster than spitfireXIV.

With 1700HP @ 9.8km,Ta152H1 is ?km/h faster than spitfireXIV?

 

[TempestMKV]

This picture tells everything.
MW50 is completely useless above 6.8km with Jumo213E.

 

[delcyros]

MW50 is completely useless above 6.8km with Jumo213E.

I don´t think so:

To help it [Ta-152-H0] attain this speed it used the MW 50 water-methanol injection system mainly for lower altitudes (up to about 10,000 m or 32,800 ft) and the GM-1 nitrous-oxide injection system for higher altitudes, although both systems could be engaged at the same time.

Altough the gain by MW-50 boost was limited at the altitude in question, both GM-1 and MW-50 could be switched on simultaneuosly.

 

[Kurfürst]

This picture tells everything.
MW50 is completely useless above 6.8km with Jumo213E.

What, a picture drawn by you with colored pencils...? In which you actually erased the original speed curves for the Ta 152H?

I am speechless..

MW 50 was effective up the Jumo 213s full throttle height, up to which the supercharger was capable providing nominal manifold pressure that was around 9.8 km from the graph in static conditions, and about 1000-1500 meter higher in full throttle level flight because of ram.

In fact, MW 50 would effective even above full throttle height, it still added around 4% extra power because of its charge cooling properties, but at those altitude it was generally considered a waste of booster liquid for so little gain.

Using GM1 and MW 50 was probably possible on the Ta 152H at the same time (or perhaps not), but there would be little point in it. MW50 was used as a charge cooler, GM1 did the same trick plus it also delivered oxygen to the engine. So using MW50 next to it would be kinda superflous.

 

[Marshall_Stack]

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.

I have never heard this before. What I have always read, the speed of the Hellcat is around 376 mph and the Corsair (F4u-1) around 421 mph. They have the same engine, but the Corsair had a bigger prop and less fuselage drag. I always wondered if the Hellcat's speed was conservative but that is how it appears in the performance charts.

 

[Kurfürst]

Its called 'position error correction'.

 

[Soren]

This Tempest guy needs to grow a brain...

 

[TempestMKV]

What, a picture drawn by you with colored pencils...? In which you actually erased the original speed curves for the Ta 152H?

I am speechless..

MW 50 was effective up the Jumo 213s full throttle height, up to which the supercharger was capable providing nominal manifold pressure that was around 9.8 km from the graph in static conditions, and about 1000-1500 meter higher in full throttle level flight because of ram.

In fact, MW 50 would effective even above full throttle height, it still added around 4% extra power because of its charge cooling properties, but at those altitude it was generally considered a waste of booster liquid for so little gain.

Using GM1 and MW 50 was probably possible on the Ta 152H at the same time (or perhaps not), but there would be little point in it. MW50 was used as a charge cooler, GM1 did the same trick plus it also delivered oxygen to the engine. So using MW50 next to it would be kinda superflous.

If you can't provide enough boost such as 1.8ata, MW50 is almost useless, and that's why there is no "MW50" curve between 6.8km-9.8k. on the above chart.

In order to provide 1.8ata on 9km altitude, engine will have to pay a lot of output in driving supercharger(600HP?700HP?). Then what's the result ? High ata, high gross output, but smaller net output for a/c.

Trust german enginers in WWII plz, instead of forgeting to draw the curve of MW50(7km-10km), they knew exactly what is multi-stage air compressor driven by engine.

 

[Soren]

Oh my god

 

[TempestMKV]

Gross output=net output+ supercharger cost

FTH=full throttle height

Unlike Merlin or Griffon, Jumo213E can reach max. engine speed at sea level. Compared with SL and 3rd FTH, the engine's Gross output is same, but 3rd FTH net output is lower. Why? The supercharger eats some output of engine. The higher boost, the harder to maintain at high altitude.

For "Reiseleistung", supercharger eats 156 PS more than on SL; for "Hochzul", supercharger comsumes more 268PS, for "steig",more 327PS is scrafied, for "Start", need more 407PS to maintain same boost, same air quantity.

For "sonder" which is very high boost(1.8ata?), how much will be taken ? At least 500 PS! And 600 PS is not surprising.

"Sonder" provide 2050PS at SL, how much net output will be left at 3rd FTH? NO MORE THAN 1550PS! 1400PS is not surprising.

Some resources/people argure that Jumo213E can provide 1650 -1700PS with MW50 (1.8ata?)at high altitude (near 3rd FTH=9km< "start"'s 9.8km).They are just kidding us.


Also we can check the high altitude(8km-9km) output benifit from increasing the boost:

From "Reiseleistung/n=2400" to "Hochzul/n=2700", around 300PS is obtained, that's OK; from "Hochzul/n=2700" to "Steig/n=3000", more than 200PS is got, that's fine; from"Steig/n=3000" to "start/n=3250",however, only 80 PS is available!

From "start/n=3250" to "sonder/3250", how much benifit will we get between 8km-9km? Less than 80 PS? negative number? Probably.

 

[TempestMKV]

I don´t think so:


Altough the gain by MW-50 boost was limited at the altitude in question, both GM-1 and MW-50 could be switched on simultaneuosly.

Let's assume that both GM-1 and MW-50 could be switched on simultaneuosly although there are seldom original archives can prove it.

The GM1 only support three N2O flow rate, 3kg/min, 6kg/min,9kg/min.

If you turn on the least N2O flow rate(3kg/min) at 9.8km, you'll get 1420PS which is higher than "start u notleistung", therefore the boost is also higher than B4 can handle, so MW50 is needed.


If you turn on 6kg/min flow rate at 9.8km, net output will be 1580PS, at this point, Jumo213E is nearly making a all out effort because the Gross output= Net output + supercharger cost=1580+407PS=2000PS.

Pilots dare not turn on 9kg/min flow rate below 10km, otherwise engine will be overloaded.

Acording to Jumo213E chart, 3kg,6kg,9kg can be turned on between 11km-12km, 12km-13km,13km-14km respectively. I think that's the rule of using GM1.

GM1 is prcious, it can only last 17min on 6kg/min flow rate.

 

[DerAdlerIstGelandet]

This Tempest guy needs to grow a brain...

This is your final and last warning. One more and you are history.

All sides involved better keep this civil or you are going on a vacation. Soren, you have already been on a vacation, next one is permanent!

Do all parties understand?

 

[TempestMKV]

Therefore, above 6.8km, the "sonder" curve and "start" curve coincides. Ta152H1 turns on 3rd speed at 8km high, and reaches 3rd FTH at 9.8km, just like Ta152B which has different wings and no MW50.

The chart below proves my analysis.

 

[TempestMKV]

This is the comparation of Ta152H1/C1 (with MW50)and 21lbs spitfire XIV/21. They all entered WWII before VE day.

red line is 21lbs Spitfire XIV; green line is 21lbs spitfire21, btw, the spitfire21 is prototype, so production perhaps a bit slower. Anyway, the Ta152 and late spitfire share same speed.

If Ta152H1 turn on GM1 above 11km, late sptifire is much slower above 11000meters, but that's unfair unless spitfire equiped with loxygen. Furthermore, above 11km the IAS is quite small, around 250-300km/h, stall fight.....

 

[bada]

For "Reiseleistung", supercharger eats 156 PS more than on SL; for "Hochzul", supercharger comsumes more 268PS, for "steig",more 327PS is scrafied, for "Start", need more 407PS to maintain same boost, same air quantity.

For "sonder" which is very high boost(1.8ata?), how much will be taken ? At least 500 PS! And 600 PS is not surprising.

"Sonder" provide 2050PS at SL, how much net output will be left at 3rd FTH? NO MORE THAN 1550PS! 1400PS is not surprising.

.

and, please, explain how you did to calculate the power loss due the the compressor....based on what documents?
thanks.

 

[TempestMKV]

and, please, explain how you did to calculate the power loss due the the compressor....based on what documents?
thanks.

In order to calculate the compressor loss, I have to know the supercharger structure, the speed, compressing ratio, air temptarure, density, intercooler area/heat transfer coefficients, the air consumption mass....

Without those I can't bring accurate result, furthermore the test data is also different from theory result.

However, it is obviously that 1.82ata boost consumes more engine power than 1.5ata at 9000m.


When 2.03ata comes out, situation changes a little, although 2.03ata Ta152H1 faster than 1.82ata, the NET output of 2.03ata Jumo213E above 7km is still unknown, I prefer to not bigger than 1500HP.