On Soviet turning time tests. Comments Please
- Thread starter Juha
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- #22
Hello MustangRider
Yes the essence of good tactic is to try to force enemy to fight with one's rules and to avoid situation in which one is forced to fight with enemy's rules.
Soren
that's why they usually posted very good pilots with good technical understanding, with ability to notice dangers to average pilots etc, as test pilots.
VG-33
I'll look what I have, nothing on Hurricane other than some general verbal comments, and Finns dumped Cauldrons immediately, they thought that it was unsuitable to our short a/fs.
Juha
Yes the essence of good tactic is to try to force enemy to fight with one's rules and to avoid situation in which one is forced to fight with enemy's rules.
Soren
that's why they usually posted very good pilots with good technical understanding, with ability to notice dangers to average pilots etc, as test pilots.
VG-33
I'll look what I have, nothing on Hurricane other than some general verbal comments, and Finns dumped Cauldrons immediately, they thought that it was unsuitable to our short a/fs.
Juha
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- #23
Hello VG-33
Gladiator, at low level: 10-11 sec, radius ca 90m
Fokker D.XXI, only verbal with warning that the plane went easily to spin if one pulled too hard in strongly banked turn which could be easily stopped if pull was easied immediately and with some use of ailerons.
Morane, at full throttle, entry speed 320km/h IAS, end speed not given: 16 sec, 4G, radius 265m. At 180km/h IAS it was possible to achieve smallest radius, radius not given.
On Curtiss only that it was very manouvrable and that one could pull so hard in turns that he blacked out, meaning lost sight but not consciousness, if I understood correctly the pilot's comment.
Juha
Gladiator, at low level: 10-11 sec, radius ca 90m
Fokker D.XXI, only verbal with warning that the plane went easily to spin if one pulled too hard in strongly banked turn which could be easily stopped if pull was easied immediately and with some use of ailerons.
Morane, at full throttle, entry speed 320km/h IAS, end speed not given: 16 sec, 4G, radius 265m. At 180km/h IAS it was possible to achieve smallest radius, radius not given.
On Curtiss only that it was very manouvrable and that one could pull so hard in turns that he blacked out, meaning lost sight but not consciousness, if I understood correctly the pilot's comment.
Juha
drgondog
Major
The Mustang 'e' was closer to .85 and its wing/wing body had much less total drag than the spit.
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- #25
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- #27
Hello Soren
power has some effects in Soviet tests, look Spitfires
heavier Spitfire F Mk IX with more powerful engine- 17,5 sec, lighter Spitfire Mk VB - 18,8 sec.
But you are right that Soviet info for ex on 109G-14 with MW50 in use would be interesting.
Juha
power has some effects in Soviet tests, look Spitfires
heavier Spitfire F Mk IX with more powerful engine- 17,5 sec, lighter Spitfire Mk VB - 18,8 sec.
But you are right that Soviet info for ex on 109G-14 with MW50 in use would be interesting.
Juha
Thank you for the link. In high attack angles fuselage give some extra-lift, of course. And side lift could be considerable too, if in step banking turns if pilot manage to use rudder. For planes like Gee-Bee, or I-16 if used fuselage side lift was considerable and so for a lot of aerobatical planes ower days.
But AFAIK, the championship was the Polikarpov I-15 Tchaîka.Inclinated at 90% it could gave some 300-400 kgf extra force and fly or even climb (only with it's fuselage side lift) without any use of it's wings !
Back to our Spitfire, have you got it's "e" value from real experiment's or wing tunnel results?
Regards
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It mainly seems you don't know what you're talking about.
ToT P-39D: 19s / P39D-2 17.7s
LaGG 5 with forced Shvetsov 82 give 35-40 km/h more, takes 0.8 min less in climb to 5km and 3s in ToT than at it's nominal work. Etc, etc...
VG-33
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drgondog
Major
VG - I do not have the e for a Spit but I would believe it is higher than a Mustang or Laag or Yak or Me or FW. While the elliptical wing does not guarantee e ~1 it should be higher than a trapezoidal wing all other factors near equal.
The problem with these theoretical discussions (and attempts to explain away the anomalies experienced in flight tests) is that both Reynolds numbers and associiated parasite drag components differs along the entire flight path as the a/c increases bank angle and slows down.
The low drag/high power ships retain enegy better and power available exceeds power required for longer periods.
The oswald efficiency factor is useful only for the induced drag component of total drag in the free body force balance - therefore it begins to have more significant relevance as the ship is pulling high g and slowing down. Once again, the wing body effect of high AoA and curvilinear flight introduces very hard to predict factors (i.e spanwise flow, assymetric flow about the fuselage, asymmetric flow through the propeller plane, etc) which are not accounted for by simply plugging Cd0 from wind tunnel tests into the Force balance equations...
Even wind tunnel tests for CL of the airframe are not 100% reliable for Induced drag calculations in curvilinear flight.
Why thank you VG-33!
So much for keeping it friendly
Oh well I tried.. I'm outta here, believe in what ya want pal..
Why thank you VG-33!
So much for keeping it friendly
Oh well I tried.. I'm outta here, believe in what ya want pal..
Sorry, i didn't want to hurt you. Anyway: Show us a soviet document where you don't see influence of the weight to power ratio on overhall flying datas.
Regards
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The Spitfire Mk.IX was 300 kg heavier than the Mk.V correct ? And featured how much more power ? 200 hp ? Thats a 0.3 sec improvement for an a/c with 300 kg more weight and 200 more hp.
The Bf-109G10 was just as heavy as the G-2, yet it featured over 400 more horsepower, now that would yield atleast a 1 sec improvement if you ask me. So that's a 19 sec turn time for the G-10 acording to Soviet charts. Using the same method the 150 more hp of the K-4 would bring this time down to 18.8 sec for the K-4. (This is all for while running with MW-50 ofcourse)
Now I must admit that actually does make sense.
The Bf-109G10 was just as heavy as the G-2, yet it featured over 400 more horsepower, now that would yield atleast a 1 sec improvement if you ask me. So that's a 19 sec turn time for the G-10 acording to Soviet charts. Using the same method the 150 more hp of the K-4 would bring this time down to 18.8 sec for the K-4. (This is all for while running with MW-50 ofcourse)
Now I must admit that actually does make sense.
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- #34
Hello Soren
Spits, Mk IX was some 380kg heavier, the power difference depended on boosts, maybe 200 hp is a good guess for a Soviet test, in west the difference was bigger, up to ca 450hp (higher octane fuel)
But but 109G-2 weighted a bit under 3050kg, K-4 3400kg and I doubt that G-10 was much lighter.
Juha
Spits, Mk IX was some 380kg heavier, the power difference depended on boosts, maybe 200 hp is a good guess for a Soviet test, in west the difference was bigger, up to ca 450hp (higher octane fuel)
But but 109G-2 weighted a bit under 3050kg, K-4 3400kg and I doubt that G-10 was much lighter.
Juha
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The weight of the K-4 was 3,364 kg, and the weight of the Bf-109G-10 was 3,148 kg IIRC. Which is abit heavier than the 3,050 kg of the G-2, that's true. Anyway a 18.8 sec turn time for the K-4 seems very reasonable for a 525 hp increase in power while weight increased only by 286 kg.
IIRC Gene (Crumpp) arrived at a similar result, the K-4 being very close to the Spitfire IX in sustained turn rate on his charts.
IIRC Gene (Crumpp) arrived at a similar result, the K-4 being very close to the Spitfire IX in sustained turn rate on his charts.
drgondog
Major
Gene and Henning have the same approach Soren - with the same limitations when modelling high g turns.
Unless Gena has changed his model - it was for a specific weight, altitude and horsepower input and Cd0 was a calculated value derived from the Thrust Hp and Induced Drag calculations. That is satisfactory for top speed level flight but will diminish in relevance in a high speed turn in which the energy gradually (or rapidly) bleeds away as the bank increases and approaches near stall AoA.
The P-51B and D were only very slighly inferior in turn compared to P-40N and P-39Q so the values of the USSR for the P-51A are interesting but not reflective of the Merlin equipped P-51. AFAIK, the P-51B/C were never flight tested against the P-40E or P-39D by USAAF Flight Test Evaluation at either Eglin or Wright Patterson.
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- #37
Soren
I recomend that You take a look on Kurfürst site and look the flight test data, Germans gave the weight of 3400kg for K-4 and 3050kg for G-1, which was the high altitude version of G-2, and some kgs heavier.
On power, look the speed of G-2s in Soviet tests, they probably used 1,42ata, so G-10 had 325hp more and K4 from 325 to 525hp more depending on manifold pressure. If you want to play safe, use the Finnish data, 1,3ata and 22sec, so G-10 had 490 hp more power etc. Was K-4 really over 200kg heavier than G-10, if so no wonder that there are stories that LW pilots prefer G-10 over K-4, but I must admit that I doubt that big weight difference between G-10 and K-4.
Juha
I recomend that You take a look on Kurfürst site and look the flight test data, Germans gave the weight of 3400kg for K-4 and 3050kg for G-1, which was the high altitude version of G-2, and some kgs heavier.
On power, look the speed of G-2s in Soviet tests, they probably used 1,42ata, so G-10 had 325hp more and K4 from 325 to 525hp more depending on manifold pressure. If you want to play safe, use the Finnish data, 1,3ata and 22sec, so G-10 had 490 hp more power etc. Was K-4 really over 200kg heavier than G-10, if so no wonder that there are stories that LW pilots prefer G-10 over K-4, but I must admit that I doubt that big weight difference between G-10 and K-4.
Juha
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Got the original docs on the K-4, and the weight is exactly 3,364 kg fully loaded (3,400 kg must be a rounded value from somewhere else), that is stated on Kurfursts site as-well. And an increase in power of 525 hp for an increase in weight of just 280 kg would definitely cut more than a second off the turn the time, so I think it reasonable to be in the area of 18.8 to 19 secs. (The K-4 featured some important aerodynamic touch ups compared to earlier 109's as-well, reducing drag a lot)
Bill,
Maybe at high altitude the P-51B D were close to the P-40N P-39Q in turn performance, but at low alt I'm quite sure both the P-39 P-40 were a good deal superior. We need only look at the lift to weight ratio here to get a clue on that.
Bill,
Maybe at high altitude the P-51B D were close to the P-40N P-39Q in turn performance, but at low alt I'm quite sure both the P-39 P-40 were a good deal superior. We need only look at the lift to weight ratio here to get a clue on that.
drgondog
Major
Here is the USAAF tests of P-51A versus P-40F and P-39D
P-51 Tactical Trials
The operative phrase is none of these tested had an appreciable advantage over the other in turn performance..
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- #40
Soren
Frankly, is this example of your adverticed unbiasment. First you forget the weight growth of 109, even water-methanol has its weight plusits tankage etc. K-4 was aerodynamically cleaner than G-6 but
Quote:" The K-4 featured some important aerodynamic touch ups compared to earlier 109's as-well, reducing drag a lot"
Which of these are the elements which reduced K-4's drag a lot when compared to G-2: the bigger oil cooler, wing bulges, Morane antenna, fuselage bulge over MG 131 breeches, while aerodynamically better than those in G-6 they were still there, antenna of direction finder, higher tail. Only easily seen improvements were the lack of the normal radio mast in late K-4s and outer wheel wells doors, which anyway were removed at least from some a/c in service.
Juha
Frankly, is this example of your adverticed unbiasment. First you forget the weight growth of 109, even water-methanol has its weight plusits tankage etc. K-4 was aerodynamically cleaner than G-6 but
Quote:" The K-4 featured some important aerodynamic touch ups compared to earlier 109's as-well, reducing drag a lot"
Which of these are the elements which reduced K-4's drag a lot when compared to G-2: the bigger oil cooler, wing bulges, Morane antenna, fuselage bulge over MG 131 breeches, while aerodynamically better than those in G-6 they were still there, antenna of direction finder, higher tail. Only easily seen improvements were the lack of the normal radio mast in late K-4s and outer wheel wells doors, which anyway were removed at least from some a/c in service.
Juha
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