Fw 190: the good, the bad and the ugly

[kool kitty89]

In the case of XP-40Q, two radiators were relocated in the wings, hence the smaller 'beard' that now housed only one (oil?) radiator.

I thought the oil coolers were in the wing leading edges and the prestone radiators were either under the nose or under the fuselage (with the chin being an intake duct)

You yourself mentioned the LE oil coolers here:
http://www.ww2aircraft.net/forum/aviation/xp-40q-able-35878-post983430.html#post983430

The initial P-40Q prototype appears to have had the oil coolers grouped with the coolant radiators all under the wing center section.

I'm not sure if either configuration caused the wing center fuel tankage to be reduced. (or eliminated the belly rack)

The annular radiator circumvents the need to have the boundary layer splitter. In case we want a P-51-style radiator, one of the fuel tanks must go - not such a big problem, there is enough of space between the spars for fuel tanks, but still a work to be done.

You also loose the centerline bomb/drop tank rack, though less of an issue if you use the annular radiator (or BMW radial) on fighter-bomber versions.

The Jumo 213A and DB 603A/E were among the best 1-stage engines, once sorted out. Strong points being the ability to use 87 oct fuel and still perform, the shortcoming being greater weight and bulk, as well as lower power above 20000 ft than a decent 2-stage supercharged 700-750 kg (dry) engine, let alone with 2-stage 1000 kg engines.

One of my points was that the Jumo 211 should have had more room for growth (at least in high altitude performance) with a single stage supercharger before a 2-stage unit was worthwhile and that a 605AS featuring an intercooler would also be useful. (perhaps less useful on the 603A given the lower compression ratios used)

I am not sure how much smaller the "nose" was on the P-40Q. It just may have hidden better behind a bigger prop hub

It still looks a bit smaller, maybe not much smaller than the P-40C's scoop, but smaller than the P-40E/F/K/L/N's.

It does appear to be deeper too, extending to the belly section.

 

[tomo pauk]

I thought the oil coolers were in the wing leading edges and the prestone radiators were either under the nose or under the fuselage (with the chin being an intake duct)
You yourself mentioned the LE oil coolers here:
http://www.ww2aircraft.net/forum/aviation/xp-40q-able-35878-post983430.html#post983430

Indeed, in the 'Vee's for victory' such configuration (oil coolers in the wings) is mentioned.

The initial P-40Q prototype appears to have had the oil coolers grouped with the coolant radiators all under the wing center section.
I'm not sure if either configuration caused the wing center fuel tankage to be reduced. (or eliminated the belly rack)

The initial configuration was a messy job IMO. The late configuration looks fine, it will not cause any changes in fuel tanks, internal an external.

One of my points was that the Jumo 211 should have had more room for growth (at least in high altitude performance) with a single stage supercharger before a 2-stage unit was worthwhile and that a 605AS featuring an intercooler would also be useful. (perhaps less useful on the 603A given the lower compression ratios used)

I was trying to go for a 2-stage S/C as soon as possible. The Jumo 211J is already intercooled, and the 211 series have, along with Jumo 213, the lowest compression ratio among the major German engines, so it will have less problems with heated charge. Since it should be going in the Fw 190 instead of the BMW, the C3 fuel will provide plenty of boost under the FTH.

 

[GregP]

The nose on the P-40Q is nowhere near as deep as the nose on a P-40N.

In a sort of strange turn of events, the Allison required less radiator airfow than a Merlin, but more oil cooler airflow. I think the XP-40Qs had redesigned oil coolers that account for a lot of the smaller air intake. The Allison used engine oil to help cool some parts of the engien and gearbox moreso than the Merlin, so some of the heat generated was not required to be dissipated by the radiator. Ergo, it had bigger oil coolers or better oil cooler design and less coolant and radiator area required.

If you look in the radiator opening of a typical P-40N (or even a P-38H/J/L) you'll see two oil coolers on the outside of a center opening. The radiator on the P-40 is right there in the center opening. The P-38 routes the center air back to the boom radiator, but the oil coolers are right up front where they are on a P-40N.

 

[kool kitty89]

Indeed: P-40 Warhawk Technical

http://www.p40warhawk.com/Models/Technical/Nose/E-K-M-N_Lower_cowl_front.gif
http://www.p40warhawk.com/Models/Technical/E cowl.jpg

http://i225.photobucket.com/albums/dd148/tjlaven/P40E_1_13.jpg

http://img43.imageshack.us/img43/2537/curtissp40ekittyhawk1we.jpg


The oil coolers actually appear to take up more area than the coolant radiator.

The installation on the P-40B/C seems more streamlined, but that's probably just due to the coolers being physically smaller and the long-nosed V-1710-33 making the entire nose look sleeker. (at a glance, the radiator ducting does look like it benefits more from ram compression effect than the later P-40D/E/F/etc radiator, but that might be more aesthetics than results in practive)

http://legendsintheirowntime.com/Other/P40_Av_4008_cutaway_W.png

http://images.fineartamerica.com/images-medium-large/p-40-tomahawk-iib-science-source.jpg



On another note, short of going with a bubble canopy, the P-40 should have been rather simple to adapt to a bulged Malcolm Hood style canopy given it already used a sliding mechanism. (I'd think this change would be simpler than the modifications actually made to the P-40N ... no modified rear decking, just the original 'scalloped' glazing along with a new canopy hood -bulged, unlike the P-40N's)

 

[tomo pauk]

On the bread'n'butter P-40, there were two coolant radiators and one oil radiator, as it can be seen on the attached picture. On the XP-40Q, with 2-stage engine, The oil cooling requirements due to the auxiliary's stage hydraulic drive slippage heating should be increased, thus requiring the more capacious oil cooling system.

 

[tomo pauk]

In order not to clog the other thread, I'll quote here the two recent posts regarding the Fw 190, and add my comment or two.

...
The Fw190 was a very good fighter bomber , but as a fighter was totally outclassed in western Europe after early 1943. Terrible wing profile, bad engine, very high wingh loading.
...

Please explain further, as i consider the Wurger as the best fighter of WWII, being the most versatile airframe from WWII (as fighter) and the easiest to fly (HoTaS)
Outclassed after early43: by what? the spitty? the Poney? it depends of altitudes only. above 6Km yes until then it was still the most agile fighter, able to change azimuts no other airplane could follow and the speed of the allies were not greater, mostly equal. Then came the D-9....
Terrible wing profile: why do you think that? Like all wing designs it was a good compromise. Semi-laminar profile made for speed, the most rigid wing structure available able to cope with the tremendous rollrate without aerolasticity and the wing was still "active" at lower speed, not like the poney's wing that need high speed otherwise it stalls.
Bad engine: ???? 801D2 bad engine? no really? check the BMW production numbers and match it with the 190 airframes production numbers and all other planes that flew with those engines, you'll see they didn't build them like2 times the number of airframes. it's just like i'll say the pw2800 is a bad engine (from my pov, it is as it's too big and need large compressors or turbo pipings to run at decent power through the altitude range ,but technically it's very well build). the 801 evolved from41 untill to end from 1650ps to 2000ps without issues, keeping the same size, the same ease of maintenance and it's reliability.
Very high wing loading: like all high speed fighters, it also provides you a certain instability what is good for maneuvrability.

I certainly don't think that Fw 190 was outclassed in Europe after the early 1943. It did struggled against P-47D from Autmn of 1943 on, though, and was decidely falling behind the Merlin Mustang, Spit XIV, Tempest and P-47D from winter of 1943/44 on. Soviets were also catching up with Yak-3 and La-7.
The Fw-190D-9 was improvement to the breed, but nothing special vs. latest Allied fighters.
The NACA 230 series was never called 'semi laminar-flow' by anyone. Again - nothing special, but it was well liked and used in ww2. Pony's wings were of much lower drag, despite being thicker (Germans measured it, too, and came to the same conclusion), while offering plenty of space for big & protected fuel tanks, useful to heavy armament, while also housing the strong U/C.
BMW 801 have had such problems with reliability in the 1st year of servicce aboard of the Fw 190 that almost made RLM kill the whole Fw 190 project. Reliability and power went up from 1942 on, though. In comparison with R-2800, the BMW 801 comes as second best. Neither was a lightweight like the Hercules, ASh-82 or some Japanese engines.
About the high wing loading - it is both strong and weak point for a fighter.