It does.
Any source that confirms that 14K on the P.24 had 930 HP on 4000m?
Aerodynamics of high-winged fighters.
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It does.
As you've just proved, it does.
Thank you.
So it is 930 HP at 3770, not 4000. Re.2000 had 1000 HP at 4000m, it was still unable to make 540-560. The I-180-2 had 950 HP at 4500m, barely making it into the stipulated 540-560 km/h bracket.
I proved quite opposite.
It doesn't matter. The difference by values is negligible to explain the maximum speed difference of >100 kph. And yes - it was a challenge to reach 560 kph with 950hp, however it _was_ possible. The P.24F was 110(!!!!) kph slower with more powerful engine and (I guess) a better manufacturing quality.
Wonderful.
It was possible. It was also far easier achievable with a V12 in the nose, on a modern and streamlined airframe.
Trying to milk the fixed U/C, strutted high wing concept past 1935-ish was an own goal, and what an own goal it was.
I compared only _monoplane_ _fighters_ with _similar_ _radial_ engines. And I just want to know the reason of the observed maximum speed difference of >=100 kph. It is toooo much to be explained by strut/gear drag only.
Even a manic obsession with a high-mounted strutted wing has to be justified somehow.
If I'm reading the Table 2 right, just the struts + U/C on the P.11 were "worth" more than 47 km/h combined.
Ok, you have explained 43% of the difference. Where is the remaining 57%?
Am I your pupil?
Why did you post obvious information in response that doesn't answer the question I asked?
I have no problems doing that.
I don't think that's something to be proud of.
You can just ignore me - I swear I won't write a word in response to you in that case. I think it's a great option for both of us.
But we need rough estimates for clean build. Struts can increase drag of fighter around 10%. So it is 3.3% lower speed. I think that in real P.11c the biggest source of drag were wings.
As I wrote earlier it had very draggy wing and fuselage surface.
You should look at PZL P.1 The concept of high gull wing shines with V-12 engine. Less drag, better forward visibility.
The best airframe of this line was PZL P.8. It had better aerodynamics with better stressed skin technology for wings.
The most interesting high wing project is probably Z-17:
samolotypolskie.pl - PWS Z-17 "Sęp I"
Superb visibility. I think that this idea can be improved by using much longer, single struts functioning as an additional lifting surface. It could also fix problems with aeroelastic instability of forward-swept wing.
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If you simulate the behavior of a large complicated object you need a large complicated grid for simulations. I have no experience with CFD, but I used simulation software to solve heat transfer problems. Does size matter in this case? Or CFD algorithms use other principles?
3.3% amounts ~15-16 kph - it is too few even according the Table 2.
Ok, what exactly was wrong? Airfoil? Inductive drag? Fuselage surface - it was all-metal airplane, I can't imagine how it was possible to achieve such high friction drag. But I will agree if you give me an example.
350 kph with a 760hp engine? Even I-15 with 635hp M-25 was faster...
I am not so sure. Seems, the wings block the back/side view at the most dangerous angle ranges.
Ok, it was an interesting idea. But still I doubt any positive effect from struts.
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swampyankee
Chief Master Sergeant
- 4,002
- Jun 25, 2013
I could tell you "exactly what aerodynamics flaws in the P.24 caused..." about the same time as I get access to a) high quality drawings of the aircraft b) some high-end CFD software, c) a decent computer and, optionally, d) a wind tunnel. This is also presuming I get comparable data on the aircraft to which you're comparing it.
Actually, giving the data (and an appropriate consulting fee) to Dave Lednicer would be a much better idea.
GrauGeist
Generalfeldmarschall zur Luftschiff Abteilung
It's very well documented that Lavochkin and Gorbunov mated the engine/cowling from an Su-2 onto the front of a LaGG-3 airframe.
Prove otherwise.
I would appreciate any references to documents.
It's the presence, not the absence, that needs to be proven. I have not seen anywhere any mention of _documents_ about transfer of drawings from Sukhoi to Lavochkin. What was written in popular literature was often just unsubstantiated opinion. It is enough to look at the cowlings of the La-5 and the Su-2 to realize that they are quite different.
The question was studied not so long ago by Gennady Serov, he failed to find in the archives any mention of the transfer of the drawings to Lavochkin. But he managed to find the name of an employee from the design bureau of Shvetsov, who helped Lavochkin a lot with the engine cowling. And the "design" itself was carried out on an urgent basis, often based on sketches, not official drawings.
Gorbunov did not design any new versions of the LaGG, unlike Gudkov. He suggested a project of a dive bomber which was never built.
It was GUDKOV who designed the Gu-82 with a Su-2 type cowling. Perhaps even using Sukhoi's drawings. But not Lavochkin or Gorbunov.
Gu-82:
Su-2 M-82:
LaGG-5:
Attachments
675 hp without supercharger and ram effect. And don't forget that total wing area matters, it is 18m2 vs. 21.9m2.
With same engine power and ceiling it would be 394 vs. 367 kph - 27 kph adventage.
23% higher wing area in case of I-15, 21% higher third power of speed in case of P.8. No magic here. Quite equivalent airframes using struts, but P.8 prototype is ready 2 years earlier and not developed to production aircraft (without aerodynamic tweaks).
Why do you think that metal means faster? Actually wooden surfaces were usually much smoother in the era.
Metal allowed for easy stressed skin construction that was inherently water-proof, but there were stressed skin wooden airplanes too (perfected by Fokker, Mosquito is also a beautyful example). The biggest metal advantage is ability to scale production.
In polish fighteres there were rearview mirrors. Sudden attack from behind was impossible. And with eyes level aligned with wing surface the arc covered by wings is very minimal, you can see that wing part close to fuselage became very thin for the purpose of increased visibility.
And thats why idiot-engineers are using them all the time?
Strut lowers a weight at the expense of increased drag. If is a clear tradeoff!
For fast aircrafts with heavy (high total mass fraction) engines that tradeoff became not favorable (actually the important thing is mass of engine, propeller and fuel with all installations).
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There is no single dominant reason, just a lot small factors. The biggest are draggy technology of wings, Towend ring instead of naca cowling, fixed landing gear, struts.
It makes no sense to improve them one by one, new modern airframe was needed. Unfortunately before the war Polish Air Force was concentrated on bomber and multirole (failed) programs, so classic fighter of next generation was not ready on time.
Generally speaking PZL P.1 is an aircraft from 1929. Much improved P.8 is from 1931. Their brilliant constructor died in 1932 in air crash accident, unfortunately he was the only one who had authority "soft political power" to promote new modern technologies and ideas in air force.
P.7 is a radial engine variant, introduced in line in 1933. P.11c and P.24 are the following parallel development lines using newer and heavier engines (for single and double radials), with first deliveries in 1936. They didn't use the new improved and less draggy, smoother wing design of P.8! The lack of closed canopy and aerodynamic improvements in P.11c was a choice of customer, it is the same generation as P.24 with Bristol engines.
PZL.38 prototype (low wing monoplane with retractable landing gear) was ready in 1937, and it also had issues with wavy wing surface and lack of smooth riveting, that clearly lowered max speed by ~30 kph (there was a problem with aerodynamic tunnel correlation).
What aircraft of the two was without a supercharged engine?
