Author Topic: Fw-190F8/U1 (Read 1744 times)

senna · « **Reply #30 on:** January 03, 2004, 06:06:38 AM »

To all that stuff you wrote on the A5, if its true.

:

From my own recolections, the standard A4 did not have MW50 on front line units. It had plumbing and provisions for it so may have had test numbers produced in Germany. Far as I know only a few were ever equiped with MW50 and they were used in a raid. The A5 did not have MW50 as I originally stated.

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Over that alt, it's impossible to run the engine at higher MP than the normal maximum (there's not enough air to do it), and so the MW50 does nothing other than cooling the mixture a bit, adding no power at all.

Actually its about 4% additional power due to charge cooling alone. Dont remember where I read that but I believe I read that somewhere on the internet.

RRAM · « **Reply #31 on:** January 03, 2004, 06:33:20 AM »

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Originally posted by senna

Actually its about 4% additional power due to charge cooling alone. Dont remember where I read that but I believe I read that somewhere on the internet.

4% seems a lot to me. Certainly charge cooling should have some effect, but 4% seems too much. And should increase slowly as altitude increases.

the link to where you read it should be helpful...try to find it, please

Badboy · « **Reply #32 on:** January 03, 2004, 12:43:17 PM »

Hi,

My source indicates that the entire F series Fw190 was able to carry upto 900 liters of external fuel in 3 x 300 liter drop tanks.

Badboy

HoHun · « **Reply #33 on:** January 03, 2004, 12:51:40 PM »

Hi Rram,

>Certainly charge cooling should have some effect, but 4% seems too much.

Why?

>And should decline slowly as altitude increases.

Why?

Regards,

Henning (HoHun)

RRAM · « **Reply #34 on:** January 03, 2004, 05:11:23 PM »

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Originally posted by HoHun
Hi Rram,

>Certainly charge cooling should have some effect, but 4% seems too much.

Why?

4% in a 1800hp engine gives around 80-90hp.- sounds a lot. Why do I say this?...erm...because it sounds a lot, I have no real data on the issue so... bassically I read the % and thought "huhm, too much for a simple cooling effect"

of course seems I'm totally wrong, so if you know something more about this topic, please go ahead and talk about it. I'm willing to learn

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>And should decline slowly as altitude increases.

Why?

that was wrongly written, my fault. I intended to say "should INCREASE", not "decline"

. I've edited it, now should be correct.

The reason is that there's cooler air as altitude increases. The charge should be hotter if the air coming into the engine is (for instance) at 20ºC than if it is at -30ºC. Cooler charge-> slightly higher output. As altitude increases, air temperature goes down, thus the effect increases slowly with the altitude.

I did read a small comment about this effect in a book some 2-3 years ago. Can't recall the name, tho

.

GODO · « **Reply #35 on:** January 03, 2004, 06:17:26 PM »

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Originally posted by GScholz
In what way? The speed figures matches up nicely with the figures GODO posted in that thread you linked to, and our 190A5 has the performance of a 190A4 with MW50!
I'd say that the A5 might actually be overmodelled.

GScholz, IMO, any debate about the impact of boost systems in plane performance should be focused in acceleration and climb, not just speed figures. And the actual acceleration of AH 190A8 is .... well ... is?

senna · « **Reply #36 on:** January 04, 2004, 02:20:41 AM »

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4% in a 1800hp engine gives around 80-90hp.- sounds a lot. Why do I say this?...erm...because it sounds a lot, I have no real data on the issue so... bassically I read the % and thought "huhm, too much for a simple cooling effect"

of course seems I'm totally wrong, so if you know something more about this topic, please go ahead and talk about it. I'm willing to learn

RAMM, check out the link below.

http://www.hitechcreations.com/forums/showthread.php?threadid=100036&highlight=fw190+mw50

hohun wrote

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>Was MW50 totally useless avobe 15k?

No. It still provided a charge cooling effect that gave a 4% power increase. The much more powerful anti-detonant effect was lost, however, as the supercharger couldn't sustain the boost to exploit it.

Turns out I read that right here on this BBS. lol

senna · « **Reply #37 on:** January 04, 2004, 02:28:50 AM »

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The reason is that there's cooler air as altitude increases. The charge should be hotter if the air coming into the engine is (for instance) at 20ºC than if it is at -30ºC. Cooler charge-> slightly higher output. As altitude increases, air temperature goes down, thus the effect increases slowly with the altitude.

Normaly when a fuel or fluid is injected into a high speed air stream, what happens is the liquid will atomize into tiny droplets. This atomization causes a temperature drop in the local air stream (aborbs the heat).

I could be wrong but in other engine applications, similar techniques are used.

GScholz · « **Reply #38 on:** January 04, 2004, 03:12:33 AM »

I've always felt that the 190's acceleration was off, but that's just a feeling not a fact.

MW50 is actually equally useful at any altitude. It's just that the supercharger can't exploit the anti-knocking benefits above its rated altitude, the cooling effect however should be equal at any altitude.

RRAM · « **Reply #39 on:** January 04, 2004, 05:55:03 AM »

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Originally posted by GScholz

MW50 is actually equally useful at any altitude. It's just that the supercharger can't exploit the anti-knocking benefits above its rated altitude, the cooling effect however should be equal at any altitude.

its cooling effects maybe were useful at all altitudes.

its antidetonating effects, nope. Over 18000 feet, it gave no advantages in that department at all.

so it's hardly "equally useful at any altitude". At high altitudes it was MUCH less effective.

So, if in Aces High the Fw190A5@21K has 10mph extra speed because a 4% power output increase, what about at 0 feet?... At sea level, MW50 gave the BMW801D a 20% output increase, from 1700 to 2100hp, so it should be a rocket...

Yet Aces High's Fw190A5 is 10mph SLOWER @ the deck than the german reports of a Fw190A5 running at 1.42 ata, but hits square on the speeds reported by the american tests.

In short: it makes no sense. Aces High's Fw190A5 has no MW50 at all. As I said,it's modelled after the american data on it, The captured Fw190A5 (with no MW50) attained that speed at that altitude during american tests. That's why it reaches 415mph@21500feet in Aces High.

Batz · « **Reply #40 on:** January 04, 2004, 09:04:00 AM »

No A-Series FW190 used MW50 operationally with the exception of maybe a few jabo a4s. The AH a5 doesn't have mw 50. The MW50 System integration into the BMW801 engine was troublesome.

Some a5s were tested with a system "erhöhte Notleistung" which is basically using normal C3 fuel as you would MW50. The system best altitude was 5500m. An A8 with a full rear tanks would reach 660 kmh, an A5 680.

This system was usable for 10 minutes like mw50. It was tested on a A5 in late August 43 and was serialized on the A8 by June 44 and on the A9 by January 45.

It was preferred to MW50 because it did not require any special installation to work. The F8 used basically the same system but was only used in the low SC gear, but not in the second stage. Thus it was limited to below 1000m.

The pic's Ram posted are more likely of the g series. Some "g8s" were field modded f8s. It’s conceivable that some may have retained their mg131s.

RRAM · « **Reply #41 on:** January 04, 2004, 09:43:33 AM »

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Originally posted by Batz
The pic's Ram posted are more likely of the g series. Some "g8s" were field modded f8s. It’s conceivable that some may have retained their mg131s.

I'm not sure that some G8s were field conversions from F8s...but the inverse was indeed true: when the G series were brought to an end, many G8s were converted to F8/U1s (as Senna's quoted describes).

BTW, MG131s were easily removed on the field, so any F8 converted into G8 should have it's cowl MGs removed. 190G series were long range deep penetration fighter-bombers. It didn't make any sense in trying to make a long range jabo, fitting it with as much fuel as possible, and then not erasing any superfluous weight that would cut its range. MGs were superfluous and so they were always deleted.

As far as I can tell, no operational Fw190G mounted cowl guns, but I'll be happy to aknowledge the opposite if you can prove your point

.

HoHun · « **Reply #42 on:** January 04, 2004, 10:49:22 AM »

Hi Rram,

>4% in a 1800hp engine gives around 80-90hp.- sounds a lot. Why do I say this?...erm...because it sounds a lot, I have no real data on the issue so...

The Jumo 213A gave 1680 HP @ 5.2 km @ 3250 rpm.

At a cubic volume of 35 L and a boost pressure of 1.42 bar, that gave an airflow of less than 1.66 kg/s. MW50 was added at 0.04 kg/s.

(Edit: There is some mistake in my calculations after that point. I'll have to have a closer look.)

Regards,

Henning (HoHun)

GScholz · « **Reply #43 on:** January 04, 2004, 01:43:20 PM »

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Originally posted by RRAM
its cooling effects maybe were useful at all altitudes.

its antidetonating effects, nope. Over 18000 feet, it gave no advantages in that department at all.

Why? Wouldn't MW50 be useful at say 20k if the engine had a rated altitude of 25k? If not then why?

HoHun · « **Reply #44 on:** January 04, 2004, 02:12:42 PM »

Hi again,

>The Jumo 213A gave 1680 HP @ 5.2 km @ 3250 rpm.

>At a cubic volume of 35 L and a boost pressure of 1.42 bar, that gave an airflow of less than 1.66 kg/s. MW50 was added at 0.04 kg/s.

That should give a temperature drop of about 40 K, from which without knowing the intake air temperature (after supercharging) I can't directly calculate the power gain.

It should be enough to justify a 4% power increase easily, though.

Regards,

Henning (HoHun)