Author Topic: Fw190A-8: acceleration? (Read 4626 times)

Crumpp · « **Reply #15 on:** February 10, 2006, 10:31:52 AM »

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Apparently the extra fuel was very often needed.

No the rack was needed for the 300 liter drop tank.

The Zusatzkraftstoffbehälter im rumpf moved the CG the beyond it's normal rearward limits. This is why the oil cooler armour was increased in the FW-190A9 to ballast the nose and restore the CG limits.

All the best,

Crumpp

TimRas · « **Reply #16 on:** February 10, 2006, 11:27:25 AM »

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Originally posted by Krusty
The A-5 we have is from allied testing of a 190G that was ballasted with weight

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Originally posted by Crumpp
The FW-190A8 is modeled off of TD 284.

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Originally posted by Grits
Add to that the fact that our A-8 is overweight

Several unsubstantiated claims. AFAIK, HTC have not revealed exactly what data it has used for modeling any of its planes (And I doubt it will).

To claim something is overweight you must know:
a) How much it does weight in the model (help file weight may or may not be right).
b) How much it should weight.
So Grits, show some numbers.

Fw190A-8 in AH2 is modeled as "clean", effect of the rack is 6mph at SL (352/346mph). I know, I tested, so perhaps this is the only fact of AH 190A8 performance in this thread so far.

Krusty · « **Reply #17 on:** February 10, 2006, 02:21:35 PM »

TimRas it's been mentioned in several 190 threads over the past -- oh, say, years (not been keeping track, myself) -- that the 190A5 we have is modeled from a 190G that was ballasted to represent an A-5. You see, G's don't have cowling guns, so they put the weight of the guns back into the cowling (ballasted), but didn't know any better, because the 190G and the 190A-5 fly fairly different, due to several factors.

So basically our "A-5" doesn't fly much like a real A-5, from what I understand.

Hell, I personally think the 190s need a LOT of work, but I don't expect it any time soon. They redid the entire 3D modelling and still can't fix the flight model problems, so I suspect it'll be another 5 years before any more changes are made. That doesn't stop me from hoping, though.

justin_g · « **Reply #18 on:** February 10, 2006, 02:36:32 PM »

#1 & #2 are fact.

A-5 performance is a match for USN G-3 trial in climb & speed.

Community members provided A-8 docs to HTC(gatt & vermillion were involved, iirc) some of which are available here.

Crumpp · « **Reply #19 on:** February 10, 2006, 03:30:49 PM »

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I am puzzled by the (apparently) ridicuolus acceleration of our 190A-8. Try a clean A-8 with 75% fuel, climb to 20K (at default climb speed), then hit autolevel and WEP, and measure the time it takes to get to 375mph. Rack or not, it seems weird.

They have way too much drag I suspect. Since HTC is modeling them off skewed data the numbers do not match.

Using flight tested data we can get a CD(tot) of .21 for the FW-190A5 and .22 for the FW-190A8 in clean configuration.

Which should be pretty close as the germans were the only ones in WWII AFAIK to windtunnel test motor installations.

I am sure someone will come join the thread and point that out as an error. But according to the Royal Air Force Ministry of Aircraft productions fact finding mission

All the best,

Crumpp

Grits · « **Reply #20 on:** February 10, 2006, 03:51:23 PM »

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Originally posted by TimRas
b) How much it should weight.
So Grits, show some numbers.

I dont have them anymore, but Crumpp sent me some documents that showed the A-3, A-5, and A-8's weights in empty/standard combat/max weights. The weight listed on HTC's sight for the A-8 (if that is what its modeled at) was significantly higher than that document showed. Sorry I dont remember the exact numbers, but if you must know them, Crumpp can show them if he wishes. Bottom line is I was satisfied the A-8 is very overweight if its modeled at the HTC listed weight.

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Fw190A-8 in AH2 is modeled as "clean", effect of the rack is 6mph at SL (352/346mph). I know, I tested, so perhaps this is the only fact of AH 190A8 performance in this thread so far. [/B]

The A-8 is double penalised because it is not modeled clean, its modeled on a plane that had the ETC rack but listed as "clean". So, add the DT/ETC rack and you have a plane modeled in its "clean" form with the ETC and added another ETC racks worth of drag.

niklas · « **Reply #21 on:** February 10, 2006, 03:59:19 PM »

The A-8 was slower than a A-5 by 12km/h at same power settings. This according to a fw190 report. Reasons:
- Mg131 Bulges larger
- no polished finishing but smooth painting (not as good)
It´s still listed with 555km/h or so.

niklas

gatt · « **Reply #22 on:** February 10, 2006, 04:18:16 PM »

THX Crumpp fo rthe first attempt to reply about the possibility of very low acceleration of AH2's 190A-8.

Crumpp · « **Reply #23 on:** February 10, 2006, 04:55:10 PM »

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which is in the region of 200-300kg

It's 166Kg's difference between an FW-190A8 fighter variant and an FW-190A5 fighter variant with a 22.7% power increase in the A8's favour.

As a ballpark figure for top speed, according too Francis H. Dean, each 1000lbs gives about 2 mph speed reduction.

If you calculate the FW-190A8's CD(tot) using TD284 data it comes out to .0259.

That is a 15% increase in drag. Hitech was calling a 25% increase in drag of the FW-190A5 over the new type prototype FW190V5g as being "Fishy".

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- Mg131 Bulges larger

Larger intakes on the FW-190A8 when fitted with an Erhöhte Notleistung für Jäger system.

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- no polished finishing but smooth painting (not as good)

That is a mistranslation. It happens when dealing with German and I have seen native speakers argue over the meanings of the some of the idiomatic or specific jargon.

In the original German, it is a normal finish for a Luftwaffe aircraft.

All the best,

Crumpp

Crumpp · « **Reply #24 on:** February 10, 2006, 04:58:50 PM »

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THX Crumpp fo rthe first attempt to reply about the possibility of very low acceleration of AH2's 190A-8.

Np,

It is just about impossible to have a discussion on these boards anymore about the history or development of a particular aircraft without somebody turning it into a totally silly plane comparision thread.

All the best,

Crumpp

Grits · « **Reply #25 on:** February 10, 2006, 06:25:39 PM »

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Originally posted by Crumpp
It's 166Kg's difference between an FW-190A8 fighter variant and an FW-190A5 fighter variant with a 22.7% power increase in the A8's favour.

So, on HTC's page for the A-5 they list it at 8586lbs (3893kg's). If the FIGHTER variant of the A-8 is only 366lbs (166 kg) heavier than the A-5 it should weigh 8949lbs (4059kg) but it doesnt, it is listed as 9682lbs (4391kg). Thats 733lbs (332kg) more than the difference between the fighter versions of the A-5 and A-8 should be. The actual difference in the A-5 and A-8 in AH (if the HTC pages are actually the modeled weights) is not 366lbs (166kg) like its supposed to be its actually 1096lbs (497kg)!! Where did the extra 733 pounds come from?

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Originally posted by justin_g
The normal loaded weight on the HTC plane page = 9682lbs(4393kg), TD 284 weight charts give loaded weight = 4391kg to 4400kg.

What is "normal" weight? That chart for TD 284 is already known to list the speeds of the plane as "clean" when it in fact had the ETC rack on it, is it not logical to assume that they also have the weight wrong? What is the weight of an ETC rack? I doubt that rack can account for the 733lbs extra weight, so something else is wrong.

Crumpp · « **Reply #26 on:** February 10, 2006, 07:13:31 PM »

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So, on HTC's page for the A-5 they list it at 8586lbs (3893kg's)

They get that from EB-104's test. The USAAF tested at their combat weight which IIRC is 60 percent fuel. It's a common practice as no aircraft actually fights at it's take off weight.

The United States Forces will commonly use empty service weight to compare realitive weight creep. Using that yardstick, the FW-190A8 gains 54Kg over the FW-190A5. The rest of the "weight gain" is consumables.

If you compare Rechlin flight-tested at 3850kg combat weight you will find that EB-104 is 2.5% pessimistic at low altitude and less than 1 % pessimistic at 2nd gear supercharger FTH. It gives good agreement within 3%, it is just about as close to the 3% edge as you can get below FTH.

It's the 10mph at lower levels that hurts.

As the aircraft gets heavier of course it gets even faster at lower altitudes but losses on the FTH.

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What is "normal" weight?

Here is the weights and CG limits for some of the FW190 series.

FW-190A2 and FW-190A3 Weights:

Leergewicht - 2900Kg

Rüstgewicht - 3141Kg

Fluggewicht - 3855 kg ohne MGFF

- 3978kg mit MGFF (Fabers FW-190A3 set up)

Schwerpunktslagen x is .55m bis .75m hinter Vorderkante wurzelprofil.

FW-190A4

Leergewich - 2900Kg

Rüstgewicht - 3148Kg

Fluggewicht - 3862Kg ohne MGFF

- 3985Kg mit MGFF

Schwerpunktslagen x is .55m bis .75m hinter Vorderkante wurzelprofil.

FW-190A5

Leergewich - 2960

Rüstgewicht - 3312Kg

Fluggewicht - 4088Kg Focke Wulf flight testing determines there is no difference in aircraft performance with or without wing armament. All fighters now produced with full wing armament.

Schwerpunktslagen x is .50m bis .73m hinter vorderkante wurzelprofile.

FW-190A6

Leergewicht - 3000Kg

R�stgewicht - 3365Kg

Fluggewicht - 4189Kg

Schwerpunktslagen x is .52m bis .73m hinter vorderkante wurzelprofile.

FW-190A8

Leergewicht - 3050Kg

R�stgewicht - 3438kg

R�stgewicht - 4272Kg

mit Zusatzkraftstoffbeh�lter im rumpf - 4392Kg

Schwerpunktslagen x is .48m bis .69m hinter vorderkante wurzelprofile.

Mit Zusatzkraftstoffbehälter im rumpf schwerpunktslagen ist .74m hinter vorderkante wurzelprofile.

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leitwolf says:
"Leergewicht" => empty weight
"Rüstgewicht" => fully armed and equipped plane without ammo/fuel/pilot (unsure on what constitutes a "Rüst"weight tho)
Fluggewicht => T/O weight
"Schwerpunktslage .55m bis .75m hinter Vorderkante Wurzelprofil." => center of gravity 0.55m-0.75 behind the leading edge of the wing measured at wingroot
"mit Zusatzkraftstoffbeh�lter im rumpf" => when using internal aux fuel tank (probably referring to the [optional] internal fuel tank on A-8's [for C3 injection or increased range])

All the best,

Crumpp

Grits · « **Reply #27 on:** February 10, 2006, 09:31:23 PM »

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Originally posted by Crumpp
the FW-190A8 gains 54Kg over the FW-190A5. The rest of the "weight gain" is consumables.

So where do you think they get the extra 1096lbs? Thats a heck of a lot, but I suppose it could all be fuel?

Krusty · « **Reply #28 on:** February 10, 2006, 10:34:30 PM »

The 190a8 was supposedly the best of the pre-Dora 190s. It was the most agile, the best performing, and the most fearsome when fighting allied planes. However in AH it is a flop. Funny how AH is alone in its modeling of the A8, vs all the other games that have ever existed.

I think weight is a part of it, yes. However I think the instability is a larger part of it.

justin_g · « **Reply #29 on:** February 11, 2006, 12:24:26 AM »

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Originally posted by Crumpp
It's 166Kg's difference between an FW-190A8 fighter variant and an FW-190A5 fighter variant with a 22.7% power increase in the A8's favour.

I'm gonna have to call you on that one...

From your own numbers:

FW-190A5
Fluggewicht - 4088Kg

FW-190A8
Fluggewicht - 4272Kg
with 115lt tank - 4392Kg

Dunno where you got 166kg from

4272kg - 4088kg = 184kg
4392kg - 4088kg = 304kg

Hmm, 184-304kg difference - sounds alot like what I said in the first place...