Focke Wulf light fighter

[spicmart]

Misspoke above -The simple equation for ROC is (T*V - D*V)/W

So, in yor example, the lighter of the two FW 190s assuming all else equal, will have a better rate of climb.

Where the W/L comes into play for your example is when parasite drag of the two are equal, but the wing area is different - is that for the same veocity the larger wing/smaller CL in this comparison - has less Induced drag, which influences the above equation.

The devil in the details is that for same airfoil and wing construction, the profile/parasite drag should be lower for the smaller wing area version perhaps offsetting higher Induced drag.

Thanks for clarifying!

 

[tomo pauk]

The regular 190 wing is rather thick up front which could to house the gun and the UC.
I wouldn't adopt anything from Messerschmitt fighters, too risky. Would rather trust an inhouse FW design or ask Heinkel or NAA for that matter...

(my bold)
Back to this tidbit.
He 100 was probably the closest to a light fighter that LW might've gotten. Obviously, it is not a FW I'm not sure how viable would've been the mating of the wing design from the He 100 on a FW-designed fuselage (whether the modified one from Fw 190, or hopefully, something new), but potential for a low-drag and low-weight fighter was certainly there.
No need to mention that surface cooling is out of the question.
What might the l-w fighter looked like, and what to do with it? With a DB 601E or the down-rated 605A, it should've been no worse than the MC.205 or the Yak-3 (but better at higher altitudes than the Yak). With more power, eg. with the 605AM, it should've been as capable as the Yak-3 with the VK-107 engine (but with the far better reliability of the engine). Guns - for the extra light version, three sped-up MG FFMs with belt feed, and, for the West, replace the motor cannon FFM with MG 151/20 or with MK 108; no MGs what so ever.

 

[tomo pauk]

Well, that's the Dora as-is, not a hypothetical lightweight one to compare with your 605 powered one. Sure, the Dora can't be lightened as much due to the heavier engine, but already if you save 300kg in structural weight you're on par with your 605 powered version in terms of power /weight. And it'll almost surely be faster due to more power with very similar drag.

I've missed this post.
Saving 300 kg just from the structural weight is not an easy task on such as small aircraft, whose structural weight (ie. mostly the weight of the fuselage and wings) was already small. Eg. the whole wing assembly was just 1/3rd of the weight of the powerplant section, and we still have less firepower power than the 190As or the DB-605-powered 190s.
We can recall that l-w 190s proposals by Fw included cutting the weight of non-structural members, like removal of cowl MGs, wing cannons, respective ammo, protection for the pilot and fuel, but never the structural weight.

Now, the big advantage of the 601/605 powered version is that it can be available much sooner than the versions that need to wait for the 603 or 213 to be available, by which point the LW has to a large extent ceased to exist as a significant force. But the RLM might refuse to go ahead with a bf109 alternative with the same engine. I think it was only after using a radial that Tank's fighter plans were looked on favorably by the RLM, as the DB engine supply was already spoken for. But assuming that hurdle can be overcome, might make sense to just cancel the 801 outright and have BMW run shadow factories for 601/605 production.

BMW 801 was with it's shortcomings, like that of the weight, fuel consumption, size (= will add drag vs. a powerful V12), and manufacturing time and cost. So in hindsight, having BMW to make DB 601/603/605 indeed has merit. The decision needs to be made a few years before the ww2, though.
Tank picked the BMW 139 to power his new fighter due to the promise of ~40% more power vs. the DB 601A back in 1938, as well as the expected low weight of the powerplant, while counting on lowering the drag via smart installation and taking advantage of the extra exhaust thrust vs. the 601A. Another drag reduction measure was the choice of the wing size, that was even smaller than what the 109 had. Cantilever tail, retractable tailwheel, fully covered U/C - the 1st Fw calculations hoped for 680 km/h (!!) with a 2750 kg aircraft (!).

However, the 820 kg BMW 139 was dumpster fire, and was replaced with the very heavy, if more reliable 801, the Fw 190 grew in size and weight, and the rest is history

 

[spicmart]

(my bold)
Back to this tidbit.
He 100 was probably the closest to a light fighter that LW might've gotten. Obviously, it is not a FW I'm not sure how viable would've been the mating of the wing design from the He 100 on a FW-designed fuselage (whether the modified one from Fw 190, or hopefully, something new), but potential for a low-drag and low-weight fighter was certainly there.
No need to mention that surface cooling is out of the question.
What might the l-w fighter looked like, and what to do with it? With a DB 601E or the down-rated 605A, it should've been no worse than the MC.205 or the Yak-3 (but better at higher altitudes than the Yak). With more power, eg. with the 605AM, it should've been as capable as the Yak-3 with the VK-107 engine (but with the far better reliability of the engine). Guns - for the extra light version, three sped-up MG FFMs with belt feed, and, for the West, replace the motor cannon FFM with MG 151/20 or with MK 108; no MGs what so ever.

It was the He 100 (did it have a laminar flow wing?) I was thinking of when I pondered about a German fighter in the extralight class of fighters like the Yak-3 which is touted the supreme dogfighter of the war. The Yak-3 with Vk-108 would be the opponent to beat (He 100 with DB 605D).

Yak fighters were all very light. They must have sacrificed something for that, something German designers deemed important...

The Yak-9U with VK-107 in the chart you posted is comparable your lw fw 190 but weighs 350 kg at least less.
An Fw 190 (large/small wing) with ASh-82-FN would have been interesting, too.

 

[tomo pauk]

It was the He 100 (did it have a laminar flow wing?) I was thinking of when I pondered about a German fighter in the extralight class of fighters like the Yak-3 which is touted the supreme dogfighter of the war. The Yak-3 with Vk-108 would be the opponent to beat (He 100 with DB 605D).

Thing to note might be that German V12s were in general better engines than the Soviet V12s, if we look at combination of power at any altitude, weight penalty, and reliability. The VK-107 and -108 were very unreliable, and very late.

Yak fighters were all very light. They must have sacrificed something for that, something German designers deemed important...

Not just what German engineers deemed important.
In general, firepower was meh, especially for standards of 1944-45, engine series was light and again well behind the curve (on same fuel, a Merlin III in 1939 is better even than the 105-PF2), fuel quantity was low, the drop-tank facility was not there. Soviet attempts in producing LR fighters resulted in over-weight and under-performing aircraft.
It might be argued that Yakovlev's engineers made probably the best game possible with the weak hand they were dealt, but making a good game with an excellent hand usually netted a much better end product. Soviets in general have had problems in making production aircraft to perform as good as the prototypes.

The Yak-9U with VK-107 in the chart you posted is comparable your lw fw 190 but weighs 350 kg at least less. Was it a "better" fighter (1-on-1) then?
An Fw 190 (large/small wing) with ASh-82-FN would have been interesting, too.

Yak-9U with a working VK-107 was, at least on the paper, about as good as the Fw 109D-9 with MW 50 or with C3 fuel. It carried one cannon less, and also less fuel. Again, the VK-107 was the Achiles heel.
'My' 190 lite should have the DB 605ASM (if not the 605D) in the nose by the time Yak-9U/107 is available. That is some 1550-1600 HP vs. 1300 at 6 km, and 1800-1850 HP at low level vs. 1600-1650.
(similar like P-51D vs. 109D-9?)
Better firepower for the 190, too.
We'd be getting a pretty even fight down low, with 190 lite getting the upper hand as the height increases? If the DB 605D can really push 2 ata with C3 + MW 50 for 2000+ HP, the 190 should be coming ahead at all altitudes.

An Fw 190 (large/small wing) with ASh-82-FN would have been interesting, too.

Soviet engine reverts the weight spiral, so in theory it is a good move (bar the thing that Germans can barely land their hand on a fully functioning 82-FN).
If Germans can have G&R start making the 14R, that can help to turn the weight spiral of the complete aircraft down, too.

 

[Shortround6]

Thing to note might be that German V12s were in general better engines than the Soviet V12s, if we look at combination of power at any altitude, weight penalty, and reliability. The VK-107 and -108 were very unreliable, and very late.

As Tomo has noted, very late. The VK-106 and VK-107 were in development in 1940. Then things get grey. They don't get developed in time forcing continued use of the VK-105. Even in 1946 production is stopped and restarted due to production/quality problems. Most sources don't say much more than that. I have no idea if in peace time they wanted better reliability/engine life over what they accepted in war time or if the new engines didn't mean wartime standards. If you are having trouble in 1946 the chances of them being useful in 1944 are about nil.

If Germans can have G&R start making the 14R, that can help to turn the weight spiral of the complete aircraft down, too.

Again the GR 14R is sort of vaporware.
1944 book (and who knows were they got the information, the forward was written in Jan 1944 so the GR factory was still in German hands and would be for months)
gives the following.
Displacement..................38.7 L
CR........................................6.8 : 1
Supercharger ratios.....6.5 : 1
............................................9.0 : 1
Weight.............................1805lbs
fuel rating.........................92 octane
BMEP.................................213lb/sq/in

take-off.............................1590hp/2600rpm/46.5in(1180mm) hg boost
rated power.....................1,660hp/2600rpm/3300ft(1000m)
..............................................1,580hp/2600rpm/16400ft(5000m)
Cruise.................................1,320hp/2400rpm/6,900ft(2100m)
...............................................1,230hp/2400rpm/19,700ft(6000m)

Take-off power is done with 100 octane gasoline.

The power down low might be do-able.
The power in high gear is pretty unbelievable. That has got to be about the best 2 speed supercharger ever built.
Find another engine that gains 13,100ft (4000meters) and still makes 95% of its best low gear power.
They kept claiming similar high altitude power in the post war years.

I have no information on what kind of wonder supercharger they were using, like a Szydlowsky-Planiol or something else?

 

[tomo pauk]

Again the GR 14R is sort of vaporware.
1944 book (and who knows were they got the information, the forward was written in Jan 1944 so the GR factory was still in German hands and would be for months)
gives the following.
Displacement..................38.7 L
CR........................................6.8 : 1
Supercharger ratios.....6.5 : 1
............................................9.0 : 1
Weight.............................1805lbs
fuel rating.........................92 octane
<snip>

Take-off power is done with 100 octane gasoline.

The power down low might be do-able.

As before, I'd put greater credit to the German war-time data. Unlike the mr. Wiklinson, they were supposed to have the actual engine on the test stand to draw a pretty accurate picture of what the 14R-04/-05 were capable for.
We might perhaps add another 5-6% to account to RPM going from 2400 to 2500 rpm for the emergency/all-out power - talk something worse than the BMW 801D in the low gear, but similar in the high gear?
(still worse than the 801E or S)

The power in high gear is pretty unbelievable. That has got to be about the best 2 speed supercharger ever built.
Find another engine that gains 13,100ft (4000meters) and still makes 95% of its best low gear power.
They kept claiming similar high altitude power in the post war years.

I have no information on what kind of wonder supercharger they were using, like a Szydlowsky-Planiol or something else?

I don't buy the max power in the 2nd gear as listed in the Wikinison's book, , too.
They might've gotten the S/C right, though. An unit that is with curved inducer vanes, of sizable diameter (certainly more than the 280mm impeller of the 14N) and without the much clogged elbow intake. Nothing of a wonder when compared with Merlin's S/C, but more refined than what the BMW 801A/C/D or Hercules used?