Draining E in turns

[Angus]

Jeffrey Quill actually tested a 190.
He regarded it inferior to the Spit IX in all performance respect except:
a) climb at certain alt bands
b) roll rate

Wish I knew which 190, and which IX.

[mw]

Hi Nashwan:  There has to be a typo there somewhere.  I have a RAE curve for the 190 that shows about 2500 ft/min from  8,000 ft to 18,000 ft.  They did test it at 1.42 though, or at least estimate it, as there is a separate line for 1.42 with initial ROC 3,650 ft. , 3,000 ft/min from 10,000 ft to 19,000 ft.   The RAE curves I have follow closely the other two you charted. I know you've studied that subject in depth so I'll defer to your expertise.  Perhaps I'm missing some nuance of your argument, but that RAE curve you show is nuts!  

I believe the British also deliberately ignored some ratings to run the captured aircraft at settings they thought would be common in the future.

I know they based some of their comparisons on how they thought the enemy aircraft could perform in future, for example "Both the Me 109 G and the FW 190 A were originally, and in some cases still are operated at a reduced engine rating. Performances given correspond to the full engine ratings" from here.

[Nashwan]

I have a RAE curve for the 190 that shows about 2500 ft/min from 8,000 ft to 18,000 ft.

Does it give the engine ratings?

The figures I'm using are from a page out of an RAE report that Butch posted on the IL2 boards. It can't be a simple misprint, because they give figures of 3500 ft/min between 10 and 17,500 ft at 1.35ata, 2450 rpm, and also 2800 ft/min at 1.28 ata, 2350 rpm.

I suspect they've read the columns on a chart wrong, and it should be 3500 ft/min at 1.42 ata, 2700 rpm and 2800 ft/min at 1.35 ata, 2450 rpm.
That would seem to fit the other figures pretty well.

Perhaps I'm missing some nuance of your argument, but that RAE curve you show is nuts!

It is nuts, as far as I can see.  The only way I can see to get a shape like that is to increase the rpm/ata when you switch to high gear.

What I don't know is whether whatever led to that mistake in the RAE report, also affects the AFDU test, where they seem to have got some odd sustained climb rate figures against the Spitfires.

Probably not, and the figures the RAE reported were just a case of shifting all the results when compiling the tests, so the 1.42 ata figures were used for 1.35 ata, the 1.35 ata figures for 1.28 ata, etc. But it does raise at least the possiblity that when the AFDU say they were using 1.35 ata, 2450 rpm for the sustained climb tests for the 190, they might have actually used 1.42 ata, 2700 rpm. (which would explain a lot about the "sustained climb" figures they found vs the Spit Vb)

I know they based some of their comparisons on how they thought the enemy aircraft could perform in future, for example "Both the Me 109 G and the FW 190 A were originally, and in some cases still are operated at a reduced engine rating. Performances given correspond to the full engine ratings" from

Thanks, I knew I'd read something along those lines, but I searched for hours to find it without success a few weeks ago, and I had another quick look to see if I could find it before my last post.  I've got a bad habit of skimming things and missing the bit I'm looking for.

BTW, I really like the "what's new" feature

[Crumpp]

Nashwan,

Give me your email and I will send you and Angus the entire report on Faber FW-190A3.  The performance trails complete with Horsepower, climb, speed, etc...

You will find it very interesting.

Crumpp

[Nashwan]

Thanks Crumpp, I've been trying to find more info on Faber's 190 for some time.

Email is nashwantwo@yahoo.co.uk

[mw]

It looks to be your lucky day Nashwan, check your email

[gripen]

In another thread rose a question about the drag again:

Originally posted by Angus
Hello guys.
The drag of those two seems to fall short of each other, the 190 being smaller and cleaner if anything, and note, that in the real world it had a better finish.

The flat plate areas calculated for Cd0 are following:

BF274: 4,93
BS428: 4,68
BS534: 4,70
BS551: 4,80
EN524: 4,82
BS310: 4,98
MA648: 4,69
JF275: 4,77
JL165: 5,19

Fw 190A-8: 4,78

Basicly this means that four tested Spitfires had lower Cd0 than a filled and polished Fw190A-8. Generally both planes are in same ballpark.

gripen

[Crumpp]

Basicly this means that four tested Spitfires had lower Cd0 than a filled and polished Fw190A-8. Generally both planes are in same ballpark.

Lets compare the Spitfires with their contemprary FW-190 opponents:


Lets see and compare total drag @ 440fps at the Spitfires FTH altitude with the correct data:

BF 274 - 795.641828 @ 440 fps
Total Drag FW-190A5 -718.2845242@ 440 fps

BS354 - No data listed except the A/C was 7 mph slower w/50 bhp more output than the Merlin 66 @ (+18)

BS543 - 810.863789
FW-190A5 - 705.7484202

BS551 - 758.4823884
FW-190A5 - 704.890256

EN524 with 4 bladed prop - 765.4635575
FW-190A5 - 702.4712376

BS310 with 4-bladed prop - 793.0539968
FW-190A5 - 751.8834689

BS310 with 5 bladed prop - 794.0663191
FW-190A5 - 749.7161496

JL165 - done to death

MA 648 Merlin 66 (+18) SU Pump - 838.0549776
FW-190A5 - 804.8037275


BS310 - 792.6552588 Parasitic drag - 691.672177

FW-190A8 - 794.3964059 Parasitic drag - 606.4158622

At 315mph the total drag situation changes completely in the FW-190A8 favor.

JL165 vs FW-190A8 has been done to death, again in the FW-190A8's favor.

MA 648 is the ONLY Spitfire Mk IX to beat the FW-190A8 for drag and here is why:


quote:
--------------------------------------------------------------------------------
External equipment of the above four aircraft was similar with the exception that MA.648 had the new pattern of air intake.
--------------------------------------------------------------------------------

MA648 - 837.1701001 parasitic drag - 751.6212076
FW-190A8 - 869.2121249 parasitic drag - 709.9624067

The parasitic drag is always in the FW-190's favor but the total drag drops to within a few pounds of each other at 315 Mph but never swings in the FW-190's favor.

So ONE example of the Spitfire Mk IX with an experimental air intake beats the FW-190A8 in total drag. The others are behind their FW-190A contemporary the whole way.

That about covers the Spitfire Mk IX's vs. their contemporary FW-190 adversary.

Crumpp

[gripen]

Now if somebody just can bring evidence that the Fw 190A-5 was really that much faster than the A-8 at same power setting.

gripen

[Kurfürst]

Originally posted by gripen
Now if somebody just can bring evidence that the Fw 190A-5 was really that much faster than the A-8 at same power setting.

gripen

Hmm, that makes me wonder... why is any evidence is needed that the A-5 was faster than the A-8?

German docs themselves state that to start with. Add to that that it`s perfectly logical that the more draggy A-8 would be slower with the MG 131 bulges, increased weight, and the lack of l/g fairing due to mounting the bombrack...

Now all I have seen up to now shows the FW 190 made a better homework to convert engine power into speed. That means it was either less draggy and/or that it had a better airscrew. Something which I wouldn`t rule out either, practically everyone who seem to have some idea on the subject tells me how good German prop design was before/during WW2. The new report on JL 165 that Mike put on the site also suggest that the MkIX`s wooden airscrews had some problems with greater powers.

Besides I don`t understand why you guys even adding all those experimental/prototype Spits into the discussion...

Pray tell me why to compare the MK IX L.F. proty BS 543 with the experimental airscrew, the MA 648 with the experimental fuel pump? These hardly tell much of the drag state of the serialized Spitfire aircraft, considering both changes will effect the available thrust itself, which on the other hand you seem to believe to take as the same on all planes...

[gripen]

Well, the docs show over 20 km/h difference at same power setting despite the A-8 external surfaces are claimed to be "filled and polished", without ETC 501, wheel doors fitted...

gripen

[Crumpp]

Well, the docs show over 20 km/h difference at same power setting despite the A-8 external surfaces are claimed to be "filled and polished", without ETC 501, wheel doors fitted...

Been whooped to death.  Bad translation.  Original doc does not say that.  It says primed and painted.  

Crumpp

[gripen]

So where is the evidence?

gripen

[Kurfürst]

What Crummp said. How does the original German sounds like, Crummp?

Besides, Gripen, do you reeeally think 20 km/h is a lot? With all the extra drag of the A-8 added into the picture?

Hell, the non-retractable tailwheel on the 109G-6 alone meant -12 km/h...

[Angus]

And the Spitfire Mk VIII also had a retractable tailwheel.....