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03-28-2007, 04:21 PM
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#76 | | Senior Member
Join Date: Jan 2007 Location: Montrose, Colorado
Posts: 1,882
Country: | A note on the FW 190 although by the (famous or infamous) Eric Brown RN. Mind you, he called the FW the superb creation of Kurt Tank. "Stalling speed in clean configuration was 127 mph. The stall came suddenly and virtually without warning, the port wing dropping so violently that the airplane almost inverted itself. This proved to be the fighter's Achilles heel, for if it was pulled into a "g" stall in a tight turn, it would flick into the opposite bank and, unless the pilot had his wits about him, into an incipient spin." This was the A4 and sounds like what the Navy was reporting in the comparison between FW, Hellcat and Corsair. |
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03-29-2007, 10:58 PM
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#77 | | Senior Member
Join Date: Mar 2006 Location: Southern California
Posts: 1,105
Country: | Quote:
Originally Posted by Soren
For an engineer, maybe, for an aerodynamicist, no.
It supports nothing as its just simple calculated guesswork.
Check up on how much of an effect just wing AR has on the lift and drag produced by a wing.
| So, what you are saying here is that a Ta-152H fully loaded (high wing loading) will be just as agile as a Ta-152H with only a light load (low wing loading). I think an engineering equation for performance would include wing loading in some form. I am surprised that an aerodynamists equation would not. Aerodynamics is certainly amazing!
Don’t you think that it is interesting to note that Tank did not use this magical wide wing on the Ta-152C. In fact, with some agreeably shaky measurements from pictures, it looks like the C has a similar aspect ratio as the Fw-190A. You don’t suppose he thought that it would be more efficient at lower altitudes, do you. Quote:
Power ? What about actual thrust ?? | Surely, you are not implying that thrust is not a function of power, are you?  Maybe that is one of those arcane aerodynamic concepts. I suspect that if I had an engine that produced 2400 hp (mil?) and you had an engine that produced 1400 hp (Sondernotlesitung) at a given altitude, I could figure out how to generate a significant more thrust than you could. That, by the way, is the hp difference between the F4U-5 and the Ta-152H at 25,000 ft. Let me follow your logic here. You have data that shows the Ta-152H is significantly more maneuverable than the Fw-190A (was it in trim?), and there is a report from the Navy saying the F4U-1 was “much more maneuverable” than the Fw-190A (and some significant out of tolerance condition not documented in the test report (which would probably be a court marshal offense)) and concluded the Ta-154H was more maneuverable than the F4U-5?
Let’s see now:
A (Ta-152) > B (first Fw-190)
C (F4U-1) > D (second Fw-190)
B (first Fw-190) > D (second Fw-190)
Therefore
A (Ta-152) > B (F4U-5)
Must be some of that aerodynamic logic that is above engineering level.
I still have problem believing that an out of trim condition would not have been noticed and corrected by the flight test pilots. They reported the plane was very easy to fly and dogfight and speed recorded was similar to that officially given to the Fw-190A. For an experienced pilot the plane talks to him, an out of trim aircraft feels out of trim immediately, a test pilot would likely feel that like a professional voice coach picking up an out of tune note from a student. Quote: |
Davparlr, the F4U-4 isn't going to climb faster than 12.2 m/s at 8.8km (29,000 ft), at WEP it climbs at ca. 12.19 (2400 ft/min) at 8.8km (29,000 ft).
| Ouch! You got me on that one.  I misunderstood the chart. However, I am not willing to cede the rate of climb to the Ta-152H over the F4U-5 at this altitude. At 25,000 ft. the F4U-5 is generating about 550 more hp, uh, I mean, a lot more thrust  , than the F4U-4. So it is reasonable that the F4U-5 could easily exceed the F4U-4 performance at 29,000, especially since it is design to be a higher altitude fighter. Equaling the Ta-152H climbing ability at this altitude is certainly within reason. |
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03-29-2007, 11:55 PM
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#78 | | Senior Member
Join Date: Oct 2005 Location: Limburg
Posts: 871
Country: | Quote: |
Don’t you think that it is interesting to note that Tank did not use this magical wide wing on the Ta-152C. In fact, with some agreeably shaky measurements from pictures, it looks like the C has a similar aspect ratio as the Fw-190A. You don’t suppose he thought that it would be more efficient at lower altitudes, do you.
| Interesting thought!
Kris
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03-30-2007, 09:44 PM
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#79 | | Junior Member
Join Date: Mar 2007
Posts: 2
Country: | The question wasn't which piston engine performed better in combat, it was which is the best piston engine aircraft. For me its the F8F, P51H and the T-152 in that order |
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03-31-2007, 02:02 AM
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#80 | | Minister of Whoopass
Join Date: Jul 2004 Location: Long Island Native in Mississippi
Posts: 12,541
Country: | Yea, but combat experience is a plus in considering the choices...
__________________ "Boyington was a Drunk, but He was a Drunk We'd Follow Straight Into Hell..."
-- Lt. William Northrop Case |
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03-31-2007, 03:10 AM
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#81 | | Senior Member
Join Date: Nov 2006 Location: Serbia
Posts: 203
Country: | These are all really great fighters especially Mustangs and Messerschmit, but what about Russian fighters like Lavochkins La-5,7 and Yak fighters??? These were also great fighters of the war outperforming all fighters in the skies, both Allied and German.  |
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03-31-2007, 07:32 AM
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#82 | | Senior Member
Join Date: Feb 2005
Posts: 4,292
| Davparlr,
Power is good as it allows to withhold RPM's in maneuvers betters, but actual thrust is determined by the Engine + Prop. The Dora features another prop than the Anton, the Ta-152H features another prop than the Dora - the Ta-152's prop does infact produce approx. 70 kg more thrust than the Dora's.
As to the effect of wing AR, well it goes for low as-well as high altitude. The reason you want a high AR wing for high alt a/c is that you need as efficient a wing as possible in terms of lift produced pr. amount of drag - this is in order to be able to maneuver well at very high altitudes.
And about wing-loading, well it doesn't matter unless your comparing two identical a/c at different weights, what matters is lift-loading and that is CL dependant.
And as to why the Ta-152C featured a smaller wing, well that was for purely one reason - Speed. The engine was different as-well (DB-603), giving different performance at altitude. Two different designs.
You see the logic appears when you look abit closer.
Best regards 
__________________ We have built a total of about 1250 of this aircraft (Me-262), but only fifty were allowed to be used as fighters - as interceptors. And out of this fifty, there were never more than 25 operational. So we had only a very, very few.
- Adolf Galland |
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03-31-2007, 09:40 AM
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#83 | | Senior Member
Join Date: Oct 2005 Location: Limburg
Posts: 871
Country: | So was the Ta 152C better at low and medium altitudes than the Ta 152H? I know it was faster. Was it also better?
Kris
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03-31-2007, 09:41 AM
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#84 | | Senior Member
Join Date: Sep 2006 Location: Jacksonville, NC
Posts: 3,026
Country: | Quote:
Originally Posted by Soren Power is good as it allows to withhold RPM's in maneuvers betters, but actual thrust is determined by the Engine + Prop. The Dora features another prop than the Anton, the Ta-152H features another prop than the Dora - the Ta-152's prop does infact produce approx. 70 kg more thrust than the Dora's. | Sure, thrust is output of engine and propeller efficiency... Power is good for much more than holding RPM during maneuvers.
Generally speaking, for props:
Vy is going to be at utilization of max excess power. At L/D max
Vx is goingg to be at max thrust excess. AoA greater than L/D max
Obviously, the two are both contributors to the thrust generated by prop A/C. But there are so many factors going into the A/C design and performance, that single measurements never tell the whole story.
__________________ If the Army and the Navy ever look on heaven's scenes, they will find the streets are guarded by United States Marines |
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03-31-2007, 09:51 AM
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#85 | | Senior Member
Join Date: Mar 2006 Location: Southern California
Posts: 1,105
Country: | Quote:
Originally Posted by Soren Davparlr,
Power is good as it allows to withhold RPM's in maneuvers betters, but actual thrust is determined by the Engine + Prop. The Dora features another prop than the Anton, the Ta-152H features another prop than the Dora - the Ta-152's prop does infact produce approx. 70 kg more thrust than the Dora's. | There is no doubt prop efficiency is important to convert hp into thrust much as tire design converts auto engine hp into thrust. I don't have much argument here except hp is important. You can never generate a lot of thrust will little hp, no matter how good your prop is. Quote: |
And about wing-loading, well it doesn't matter unless your comparing two identical a/c at different weights, what matters is lift-loading and that is CL dependant.
| I have trouble with this. CL is not the purpose of a wing. The purpose of a wing is to generate lift. Lift is inversely proportional to CL but proportional to wing area. The absolute lift advantages in CL in one wing can be offset by increases in wing area of another.
If you keep hammering me on the aerodynamic stuff, I will have to go dig up my old aero and aerothermopropulsion books. Then, watch out, I will be a expert in how many and what gage of bracing wires are required to pull 3 "gs" without losing the upper wing or how much castor oil you have to wipe off your goggles if you run a 80hp gnome rotary engine for 45 minutes. Quote: |
And as to why the Ta-152C featured a smaller wing, well that was for purely one reason - Speed. The engine was different as-well (DB-603), giving different performance at altitude. Two different designs.
| Yes. The Ta-152 suffers from speed at lower altitude when compared to the planes such as P-51H, F4U-5, Tempest II, and even slower than the P-51D below 15k. If you were driving on the freeway (autobahn) at 70 mph (113 km/hr), then a car zipped by at 103 mph (165 km/hr), that would be an F4U-5 passing your Ta-152 at SL, then a car zoomed by at 110 mph (177 km/hr),that was P-51H, and finally one flashed by at 116 mph (187 km/hr), that was a Tempest II. Of course the engine is a big factor. Quote:
You see the logic appears when you look abit closer.
Best regards | Quote:
A (Ta-152) > B (first Fw-190)
C (F4U-1) > D (second Fw-190)
B (first Fw-190) > D (second Fw-190)
Therefore
A (Ta-152) > B (F4U-5) | Oops, You caught me on another error  . I screwed up on the flow, the last line should read
A (Ta-152)> C (F4U-5)
So lets see. Say, A=5, B=3, C=7, and D=2
we have:
5>3 So far so good
7>2 Looking good
3>2 We're on a roll
Therefore:
5>7 Uh Oh. Logic doesn't hold.
Last edited by davparlr : 03-31-2007 at 09:56 AM.
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04-02-2007, 04:27 AM
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#86 | | Senior Member
Join Date: Feb 2005
Posts: 4,292
| Davparlr,
This doesn't happen often with you but I'm going to have to ask you what exactly you're talking about ?
Wing area is no more important than CL. A large wing with a low CL can easily be matched by a smaller wing with a higher CL. And as it is a higher AR increases CL while Cd0 is lowered, this is good for instantanous maneurvers but since it also gives a higher L/D ratio it proves important in sustained maneuvers as-well.
As to Horsepower, well more is always good, however the engine has also got to be efficient for its volume - and nomatter the engine if the design of your a/c isn't clean to begin with.
As to the Ta-152H vs F4U-5, well considering the Ta-152H is more maneuverable and most likely climbs faster plus is only slower on the deck, I see it as quite superior to the F4U-5 - esp. considering the fights in the ETO weren't as often carried out on the deck.
PS:
Ta-152H-1 SL speed = 597 km/h (374 mph)
Ta-152C-1 SL speed = 617 km/h (386 mph)
This isn't slow compared to the F4U-4 or -5..
__________________ We have built a total of about 1250 of this aircraft (Me-262), but only fifty were allowed to be used as fighters - as interceptors. And out of this fifty, there were never more than 25 operational. So we had only a very, very few.
- Adolf Galland
Last edited by Soren : 04-02-2007 at 04:31 AM.
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04-02-2007, 08:54 AM
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#87 | | Senior Member
Join Date: Jul 2005
Posts: 292
| Quote: |
A large wing with a low CL can easily be matched by a smaller wing with a higher CL.
| It can match the lift, but at the expense of a lot more drag.
The coefficient of induced drag:
Cdi = (Cl^2) / (pi * AR * e)
The higher the wingloading, the higher the CL you have to pull to maintain the same turn. The higher the CL, the higher the drag (note how CL is squared in the equation) Quote: |
The reason you want a high AR wing for high alt a/c is that you need as efficient a wing as possible in terms of lift produced pr. amount of drag - this is in order to be able to maneuver well at very high altitudes.
| Which is also why you want as low a wingloading as possible. |
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04-02-2007, 05:52 PM
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#88 | | Senior Member
Join Date: Mar 2006 Location: Southern California
Posts: 1,105
Country: | Quote:
Originally Posted by Soren Davparlr,
This doesn't happen often with you but I'm going to have to ask you what exactly you're talking about ?
| Actually, I keep asking myself that quite often. After pondering my thought process a bit, I think I figured it out. We were discussing wing loading verses CL and I think my mind started jumping around. Now, let me try this and see if it makes any better sense. Wing loading determines how much force each square foot of wing must provide. If a plane is twice as heavy as another with the same wing area, each square foot must generate twice the lift at a given load, like flying level or at a given turn rate. Now the F4U-5 has 25% more wing area than the Ta-152H (314 sqft vs. 251). If the wing loading was the same, then the efficiency of the Ta-152H wing would be superior (each square foot lifting the same load with a more efficient wing). However, this is not the case. Each square foot of wing area on the F4U-5 does not have to generate the lift that each square foot of the Ta-152H has to generate for a given load. The Ta-152H wing must be more efficient in order to provide the equivalent lift (lift is a function of wing area). This should be true given the AR of the two aircraft (we don’t know both CLs). What we don’t know is whether the efficiency of the Ta-152H wing is enough, not only to balance the wing area advantage of the F4U-5, but to exceed it in performance.
We do know that both the F4U and F6F, like the Fw-190, were noted for their maneuverability. Both Navy aircraft successfully fought an enemy whose aircraft were also noted for their maneuverability. Quote: |
Wing area is no more important than CL. A large wing with a low CL can easily be matched by a smaller wing with a higher CL. And as it is a higher AR increases CL while Cd0 is lowered, this is good for instantanous maneurvers but since it also gives a higher L/D ratio it proves important in sustained maneuvers as-well.
| There is no doubt that high AR provides more lift at lower drag, hence its use in applications like the B-24 and B-29. However, even a lower AR wing can produce an equivalent lift if you are willing to accept the drag increase. You can accept a drag increase if you have the thrust to overcome the additional drag. I contend that the F4U-5 (and -4) had more than enough thrust, as compared to the Ta-154H, to overcome the additional drag generated by its lower AR. Quote: |
As to Horsepower, well more is always good, however the engine has also got to be efficient for its volume - and nomatter the engine if the design of your a/c isn't clean to begin with.
| Hmmm, the radial used in the F4U was a pretty efficient engine, for a radial, and certainly was known for its power to weight ratio, which, with a sufficiency of fuel supplies, is more important. And, it is also known for its brute power. As for being clean, I’d say that the Ta-152H is cleaner as it goes about the same speed as the F4U-4 at SL but uses less power (neither compares well with the P-51B or D). Again, brute power can trump a lot of faults (e.g. F-4 Phantom). Remember, the fastest piston powered aircraft in the world is a radial powered aircraft. Quote: |
As to the Ta-152H vs F4U-5, well considering the Ta-152H is more maneuverable
| This cannot be stated as fact. It is quite possible that the F4U-5 is equal to or better than the Ta-154H in maneuverability below 30k Quote: |
and most likely climbs faster plus is only slower on the deck
| since I don’t have the climb data for the F4U-5, I cannot agree or disagree. Also, the F4U-4 is faster, or equal to, the Ta-152H up to 25k. It is reasonable the assume the F4U-5, which is 30 mph faster at SL and 20mph faster at 30k than the F4U-4, is faster over this entire range from SL-25k, significantly, over both the F4U-4 and Ta-152H Quote: |
, I see it as quite superior to the F4U-5 - esp. considering the fights in the ETO weren't as often carried out on the deck.
| This is thread is for the greatest fighter ever. Since I am sure that, by far, most combat in WWII occurred below 25k feet, this area must be weighed heavily. Quote:
PS:
Ta-152H-1 SL speed = 597 km/h (374 mph)
Ta-152C-1 SL speed = 617 km/h (386 mph)
This isn't slow compared to the F4U-4 or -5..
| The 30 mph advantage the F4U-5 has over the Ta-152H at SL and probably up through 30k is significant. Remember the 70 mph cruise down the freeway and being passed by someone going 100. You would probably say, “that guy’s going fast!” |
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04-03-2007, 12:53 AM
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#89 | | Senior Member
Join Date: Feb 2005
Posts: 4,292
| Quote:
Originally Posted by Hop It can match the lift, but at the expense of a lot more drag.
The coefficient of induced drag:
Cdi = (Cl^2) / (pi * AR * e)
The higher the wingloading, the higher the CL you have to pull to maintain the same turn. The higher the CL, the higher the drag (note how CL is squared in the equation)
Which is also why you want as low a wingloading as possible. | Sorry Hop, but thats flawed thinking in a massive scale.
Just like CL Cdi is a coefficient, which means it needs to be multiplied by A (Area), and since the smaller wing is, well.. smaller, the slightly higher Cdi doesn't mean anything - esp. not if the AR is higher.
So no Hop, its not a lower wing-loading you want, its a low lift-loading and a high L/D ratio.
__________________ We have built a total of about 1250 of this aircraft (Me-262), but only fifty were allowed to be used as fighters - as interceptors. And out of this fifty, there were never more than 25 operational. So we had only a very, very few.
- Adolf Galland |
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04-03-2007, 01:13 AM
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#90 | | Senior Member
Join Date: Feb 2005
Posts: 4,292
| Quote:
Originally Posted by davparlr Actually, I keep asking myself that quite often. After pondering my thought process a bit, I think I figured it out. We were discussing wing loading verses CL and I think my mind started jumping around. Now, let me try this and see if it makes any better sense. Wing loading determines how much force each square foot of wing must provide. If a plane is twice as heavy as another with the same wing area, each square foot must generate twice the lift at a given load, like flying level or at a given turn rate. Now the F4U-5 has 25% more wing area than the Ta-152H (314 sqft vs. 251). If the wing loading was the same, then the efficiency of the Ta-152H wing would be superior (each square foot lifting the same load with a more efficient wing). However, this is not the case. Each square foot of wing area on the F4U-5 does not have to generate the lift that each square foot of the Ta-152H has to generate for a given load. The Ta-152H wing must be more efficient in order to provide the equivalent lift (lift is a function of wing area). This should be true given the AR of the two aircraft (we don’t know both CLs). What we don’t know is whether the efficiency of the Ta-152H wing is enough, not only to balance the wing area advantage of the F4U-5, but to exceed it in performance. | Considering the climb rate advantage at all alts and the much shorter take-off run I'd say that its quite clear that the Ta-152H's wing more than made up for the smaller wing area. Quote: |
We do know that both the F4U a | | | |