Sonder - Notleistung mit A Lader als Bodenmotor ?

[niklas]

Originally posted by butch2k
Hohun, the 1750/1780PS curve is the one labelled 1 on the chart, this one match exactly with the other data i have for 1750PS.

It also goes along with the test report of the D9 with DB603 engine (the first D9), which also reached 570km/h with 1700-1750PS

And there´s no way to gain 70km/h with just 450ps. Your prop efficiency is already dropping, you´re in a speed region where the air in local parts reach Mach1. You need a lot more power.

niklas

[niklas]

In those charts no power setting is given that describes the Sondernotleistung.

What is given is the speed (indicated) for Notleistung on the first chart. Again, aroung 570km/h. So the 2nd chart shows the power setting for mw-50, which is ~2100-2200PS.

Those docs are the background for the speed chart going around, and they confirm my opinion that the speed chart is mainly a calculated one, which may base on real flight data and experience values, but is not the direct result of a flight test. Anyway the values are not optimistic.

The speed chart nevertheless is dated April45 and at this time no 1900ps power setting was used anymore except for AG engines up to 500m (emergency)

Please understand finally that the speed chart and those table do NOT show a 1900PS power curve. Or try to convince me how you want to gain 45km/h (from 570 to 615) with just 200PS-300PS more output.(1700-1900). Unpossible....

niklas

[HoHun]

Hi Niklas,

>In those charts no power setting is given that describes the Sondernotleistung.

On page 1, a combination of speed and power is given: 611 km/h at 1925 HP.

If these 1925 HP are "Sondernotleistung" or some other power rating is irrelevant - it shows that the Fw 190D-9 reaches more than 600 km/h on less than 2000 HP.

>Please understand finally that the speed chart and those table do NOT show a 1900PS power curve.

It's in the Focke-Wulf documents: 611 km/h - 1925 HP. Do you have any other explanation than "1900 HP power curve"? :-)

>Or try to convince me how you want to gain 45km/h (from 570 to 615) with just 200PS-300PS more output.(1700-1900). Unpossible....

Two mistakes: You keep using a reference point that you don't have any absolute values for, and you keep forgetting the exhaust thrust that becomes more and more important at higher speeds.

>The speed chart nevertheless is dated April45 and at this time no 1900ps power setting was used anymore except for AG engines up to 500m (emergency)

The speed chart I have is dated 11.3.1945, the same as page 1 of the speed calculations showing the 1925 HP for 611 km/h combination.

There are two speed curves in the chart with near that speed, "Sondernotleistung mit Ladedruckerhöhung, MW50 und 1,8 ata" (606 km/h) and "Sondernotleistung" (615 km/h). These are curves 2 and 4.

Regards,

Henning (HoHun)

[butch2k]

This is indeed calculated and quite optimistic data...

I have some real test data of WkNr 210043 taken at 4250Kg @1900PS/1.50ata/3250rpm showing a speed of 560km/h @SL and 660km/h @6500m.

[VO101_Isegrim]

Butch, any guesses on what the heck this Bodenlader thing could be? Do you know anything on it`s operational service (if there is such)? Or it is just plain mistery?

Totally OFF: Can you tell me what`s the radiator position in the K-4 test with 24.5m/sec climb rate ? I guess it`s half-open, can you confirm that?

[HoHun]

Hi Butch,

>I have some real test data of WkNr 210043 taken at 4250Kg @1900PS/1.50ata/3250rpm showing a speed of 560km/h @SL and 660km/h @6500m.

That's awfully slow, considering the radial-engined Fw 190A-5 achieved 549 km/h @ sea level and 668 km/h @ 7200 m/661 km/h @ 6500 m (data from US tests).

Since the radial engine has an obvious drag disadvantage, less power (1660 HP) and less exhaust thrust (ca. 65 kp), the D-9 with 1900 HP and ca. 110 kp should obviously be quite a bit faster unless something else is wrong with it.

Could it be that your test is from the initial stage of introducing the Fw 190D-9 into service? At that time, there were complaints that the aircraft didn't perform any better than the A-series, but as far as I know, these had been solved by 1945. Accordingly the question is: Can you tell us more about this source (or better yet, post the report somewhere :-)?

One discrepancy that can't be explained by a possible date difference is that 1900 HP are reached at 1.50 ata in your report, while according to Bbury's report, it takes "Ladedruckerhöhung mit MW50 und 1.80 ata" to reach a speed in the 1900 HP range.

Regards,

Henning (HoHun)

[BUG_EAF322]

Es ist mir ganz egalwas mit dem bodenmotor loss ist.

[butch2k]

The 1900PS setting was achieved with B4 w/o MW-50, and the 190D-9 was tested in combat condition meaning no polish/no fill.

The 4th curves on Bryan's report is not for 1900PS !!! it's the one for 2100/2150PS@1.78ata@3250rpm@SL (Sonder Notleistung).

[HoHun]

Hi Butch,

>The 1900PS setting was achieved with B4 w/o MW-50, and the 190D-9 was tested in combat condition meaning no polish/no fill.

The effect of filling/polishing was maybe 10 km/h, that's not enough to explain the difference.

>The 4th curves on Bryan's report is not for 1900PS !!! it's the one for 2100/2150PS@1.78ata@3250rpm@SL (Sonder Notleistung).

Actually, if you look at page 1 of the speed calculations:

http://jagdhund.freeyellow.com/FW190D-9/D9speedWeb_01.jpg

you'll see that the necessary power for 611 km/h is listed as 1925 HP. (First line of the table "Horizontalgeschwindigkeiten - Schwebeleistung im Schnellflug" - 'horizontal speeds - equilibrium power for high-speed flight').

Regards,

Henning (HoHun)

[Naudet]

Henning, the numbers Butch mentions fit well into the picture.
Also if you compare them to the flight test of Kurt Tank in the FW190D9.
Tank gives 580km/h SL and 686 km/h at 6,6km.
And i am pretty sure Tank flew a 1900PS D9 that was polished to a high glose.

Also Pilots of JG54 mentioned that high polish increased speed by about 20 km/h.
This would fill the gap.

Even if it were only 10 km/h as you mentioned, the differences between WK-Nr. 210043 and Tanks D9 could well come from series production variation.

I have read through the entire thread now.

I would like to add the following, according to my researches i have to share the opinion of both Niklas and Butch2K.
640 km/h need more power that 2240PS.
The chart Fw5232 has no speedcurve for 2240PS.
I am pretty sure the different D9 version would have performances compared to this short summarization.

Early D9 (or 1750PS D9)
Speed:
~550km/h SL
~650km/h 6.6km
Climb
~17 m/s SL

Mid D9 (or 1900 PS D9)
Speed
~570km/h SL
~685km/h 6.6km
Climb
~ 21 m/s SL

Late D9 (2100PS D9)
~600km/h SL
~690km/h 5.5km
Climb
greater 21m/s,
i assume something like 24m/s cause increased horsepower has much more
effect on climbrate than on topsspeed


This would mean between early D9s, which are just  slighty better than the
A8, and late D9s there is such a great performance difference as i.e. between
Spit IX and Spit XIV.

I am not completely sure about the climb rates, as i don't have the knowledge to calculate anything in aerodynamics.
Climbrate for 1900PS might well be just 19-20 m/s and for 2100PS something like 21-22m/s.

Also a look to the JUMO213 development history might bring some light on which poweroutput the curve of speedchart Fw5232 are based:
Designation Take off/Emergency power KW(PS) Comments
A-1 1285(1750) Zweiganglader
AG 1395(1900) Sonderausführung
B-0 1470(2000) C3-Kraftstoff
C-0 1285(1750) für Motorkanoneneinbau
C-1 1285(1750) Serie Sep. 1944
E-0 1375(1870) Höhenmotor, C3-Kraftstoff
E-1 1285(1750) Höhenmotor, Serie 1944
EB 1470(2000) Sonderausführung
F 1505(2050) Höhenmotor
J 1645(2240) Projekt mit 4 Ventilen
T 1285(1750) Projekt mit Abgasturbolader
S 1665(2400) Projekt für niedrige Volldruckhöhen

After finding this i think we can finally assign all 5 speedcurves of the
Fw5232 speedchart to a certain JUMO213 Version.
I think it will be like this:
Curve #1,#4 & #5 are for a JUMO213AG with MW50
Curve #2 is for the "Sondernotleistungs" setting of a JUMO213B-0
Curve #3 is for the projected JUMO213S, were the comment roughly translated
means "project for low full boost pressure altitude"
As document Fw5232 is a calculated chart, it would be logical to included
projected developement stages of the JUMO213, to show which performances can be
expected in the future.

[butch2k]

You've just said it Hohun, it's a calculated power.
Carefully look at the document, the power required is calculated according to the known aircraft parameters and speeds. That means that the speed curve have been drawn before the necessary power have been calculated. The curves probably comes from other test data.

The document probably served as a preliminary analysis to determine the delta between actual required power and calculated power.

I have seen the complete Jumo curves with power at height vs ata and fuel, and i can assure you that B4+MW-50 @ 1.78ata produce 2100/2150PS @SL not 1925.

Here is part of what i'm authorized to post here :

[HoHun]

Hi Lutz,

>I would like to add the following, according to my researches i have to share the opinion of both Niklas and Butch2K.

I can see how you arrive at the belief. However, the problem is, you don't have any hard numbers.

1925 HP for 611 km/h is a hard number.

>S 1665(2400) Projekt für niedrige Volldruckhöhen

Actually, the "Bodenmotor" is labeled "mit A Lader", so it's clear it has the Jumo 213A supercharger. If you look at the speed curves, it shows no loss in power above 8 km compared to the standard Jumo 213A with B4.

If the full throttle height of the Bodenmotor appears low, it's just because the boost is very high - at lower boost, its full throttle height is that of a normal 213A at the same boost.

>the Fw5232 speedchart

Fw 5232 is just the graph paper's ID :-)

Regards,

Henning (HoHun)

[HoHun]

Hi Butch,

Your charts are interesting because they put an absolute power number on the speed graph.

However, it would be important to know the date of the report - as I mentioned, the Fw 190D-9 didn't perform as expected initially, and the Werknummer quoted in the report seems to be an early one if I remember correctly.

>Carefully look at the document, the power required is calculated according to the known aircraft parameters and speeds.

By 1945, the aircraft parameters were known pretty well :-)

>The document probably served as a preliminary analysis to determine the delta between actual required power and calculated power.

Actually, the document served to calculate level top speeds and climb rates. The speeds are the results of the calculations, not the input.

>I have seen the complete Jumo curves with power at height vs ata and fuel, and i can assure you that B4+MW-50 @ 1.78ata produce 2100/2150PS @SL not 1925.

Are you sure that boost is in these curves? I have the Jumo 213A and E curves, too, and they don't specify any boost pressures - as Jumo didn't control boost but charge mass, it made sense to omit the (misleading) boost figures.

But as I said, I consider these values contradictory, too.

Regards,

Henning (HoHun)

[Naudet]

@Henning: We don't know which modifications the JUMO213S would have compared to the JUMO213A. It might well be that it just was that "Bodenmotor mit A-Lader".  As it was a project for low alts, it would make sense to use the A-Lader instead of the E-Lader for high altittude. Lets simply say it this way. We both can't be sure what is right, as a few parts of the puzzle are still missing.
And i tend to be a little cautious not to overestiminate the performance.
Btw this seems to be the same method Rechlin used, i.e. in flightest of WK-NR. 006 they achieved topsspeeds that varied by 10km/h and for the display of speed/climb graphs the lowest attained topsspeed was used, not the highest.


@Butch: Am i right if i think, that the little dots and crosses are the data from flight tests and the lines are than drawn over them?

Edit: About Fw5232, i know its the paper ID, but its easier to type Fw5232 than always "the speedchart from Bryans Website

[niklas]

Originally posted by HoHun


1925 HP for 611 km/h is a hard number.

And it isn´t unrealistic too. But you forget that this is the power that is necessary to pull the aircraft through the air and not the engine output

Just multiply engine power * prop efficiency

2240 * 0.8 = ~1800Ps

OR assuming that at those speed prop efficiency is already lower.
2240*0.7 = 1570 PS

adding exhaust thrust power, around 150kg
150kg*9.81*611/3.6 = 250kw = 300PS

1570+300 = ~1900PS
Not bad for a rough calcualtion eh?

Here you are....

niklas