Draining E in turns

[gripen]

Originally posted by Crumpp
No that performance graph EXACTLY matches the Focke-Wulf comparison flight test's conducted for the Ta-152 development program.

So they might have used the same calculated curve for comparison.

Originally posted by Crumpp
The German text describing the condition of the planes reads, "Surface fixed and painted" on the FW-190A8.

This might mean same as filled and polished in other words, do you speak german?

Originally posted by Crumpp
Unless you have different report, the US Navy test was an FW-190A5 NOT an FW-190A8.

Well, same airframe, same ratings and almost same results given the difference in the surface finish.

Originally posted by Crumpp
My guess is it did not like the US AVGAS that had a lower aromatic content than the German aviation fuels.

So apparently you have no evidence that the problems at high altitude was caused by US avgas.

Originally posted by Crumpp
Gripen's Horsepower rating for the BMW-801D2 is only 10 hp away from the full throttle height horsepower rating at over a 600 ft. below full throttle height. Using a straight edge on the chart IMO 1730 is more accurate.

Just read the graph at 4500 ft => 1770 ps

Originally posted by Crumpp
The faster you go the more the total drag swings in the FW-190A's favor. The parasitic drag always favors the FW-190.

Also seems to me that the FW-190 also has less braking forces per mass acting on it.

So I would say David Lednicer's conclusions were correct.

You are continously using the below average JL165 data set, please use the JF275 data set.

Originally posted by Crumpp
You sure you want this version?

That's with tropical equipment.

gripen

[gripen]

Originally posted by Crumpp
Using the horsepower rating Gripen provided.  It would be nice to have full disclosure and receive a copy of this chart.

...

Engine Horsepower (bhp at test alt) - 1945

Actually that is the output I calculated assuming 2050 hp output at the first FTH with RAM. But as noted above the real output at the 1st FTH is about 2020hp using the exactly same chart as Crumpp, so we can see that at 2800ft the JL165 and the JF275 had engine output roughly 2020 hp with RAM. And by measuring rate of the power decrease above the first FTH we can calculate that at 4500ft the output was roughly 1922 hp with RAM.

Regarding the E drain in the turn, the real subject of this thread, here is the forward acceleration comparison in the level turn under various g loads at 300 mph and at 4500 ft calculated with the mass of the planes.

JF275
0g 1,551 m/s2
1g 1,452
2g 1,156
3g 0,662
4g -0,029
5g -0,917
6g -2,004

JL165
0g 1,516 m/s2
1g 1,422
2g 1,140
3g 0,670
4g 0,011
5g -0,835
6g -1,870

Fw 190A-8
0g 1,078 m/s2
1g 0,923
2g 0,458
3g -0,317
4g -1,403
5g -2,798
6g -4,503


gripen

[Crumpp]

Actually that is the output I calculated assuming 2050 hp output at the first FTH with RAM. But as noted above the real output at the 1st FTH is about 2020hp using the exactly same chart as Crumpp, so we can see that at 2800ft the JL165 and the JF275 had engine output roughly 2020 hp with RAM. And by measuring rate of the power decrease above the first FTH we can calculate that at 4500ft the output was roughly 1922 hp with RAM.

Your right, Just rechecked the chart and I missed the line.  So I have the Spitfire going at FTH level speed for less Horsepower than it actually took at a higher altitude than it actually occurred!  Let me fix that:

I just went with the listed full throttle height on Table IV and plugged in the full throttle height horsepower.  From there I used the same charts for the FW-190A8 to find the speed an horsepower output at the same altitude.

http://www.fourthfightergroup.com/eagles/jl165.html



FW-190A8 1.42ata@2700U/min

Step A - Enter Aircraft dimension Data
Wing area S (sq. feet)   196.96
Airplane weight, lbs (as tested)   9418
Wing span, ft   34.45
   
Step B - performance #s at a known altitude
    
    
Altitude (feet)   2800
Maximum speed (at test alt.- mph)   348
Engine Horsepower (bhp at test alt)   1720
Stall speed (mph, at test alt)   110

Speed (fps)
440

CL
0.225749

D(p)
988.1947

D(i)
130.1717

CL^2
0.050963

CD(tot)
0.026807

Drag (tot)
1118.3664

thrust (lb)
1682.389

excess power (bhp)
564.0221

P.E.
0.782506

Spitfire Mk IX Merlin 66 (+25)

Step A - Enter Aircraft dimension Data
Wing area S (sq. feet)   242
Airplane weight, lbs (as tested)   7400
Wing span, ft   36.1
   
Step B - performance #s at a known altitude
    
    
Altitude (feet)   2800
Maximum speed (at test alt.- mph)   364
Engine Horsepower (bhp at test alt)   2050
Stall speed (mph, at test alt)   90


Speed (fps)
440

CL
0.144365

D(p)
1071.918

D(i)
71.46502

CL^2
0.020841

CD(tot)
0.022306

Drag (tot)
1143.3834

thrust (lb)
2005.172

excess power (bhp)
861.789

P.E.
0.782506

And of course the faster you go the more it moves to the FW-190's favour.  So Lednicer was right about the drag.

Regarding the E drain in the turn, the real subject of this thread, here is the forward acceleration comparison in the level turn under various g loads at 300 mph and at 4500 ft calculated with the mass of the planes.

Probably not exact Gripen but close enough to see that unless the FW-190 is pulling 4 g's or more it's energy bleed is not as bad as the Spitfires.

Crumpp

[Angus]

Bringing some nice anecdotal stuff into the fire
Pilots account from a mission where Spitfires having a party were jumped by 190's and 109's.

"While scanning the sea, I suddenly saw the shadows of a large number of aircraft on the water, though I could not see the actual aircraft. They were very low down and making for Tunis - Rommel's final reinforcements.
I called up Ian Gleed on the R/T and reported them.
"Can't see them from down here," he replied. "You'll lead on and we'll follow you."
My section followed me down and we soon sighted about eighteen  Savoia 82's, three-engined transport aircraft. I selected one for attacking, but my machine was moving too quickly and I overshot.
Throttling back, I attacked another, closed right up and skimmed over the top of him as he went into the sea, broke up and disappeared in masses of spray with the engine cowlings bouncing over the waves.
I had time to shoot down another, which practically landed on the sea; and then a mixed formation of escorting Focke Wulfs and Messerschmitts appeared on the scene and jumped us.
   Just as I was about to attack another Savoia I glanced back and a Focke Wulf on my tail. And then, suddenly, the air seemed to be filled with Focke Wulfs. I saw one or two Spitfires leaving the area, and Ian Gleed's no.2 bale out while his aircraft went down in flames. I had the Focke Wulfs to myself. This seemed to be it.
   With the engine flat out I flew over the sea, twisting, turning, dodging, gaining a bit of confidence when I found my Spit 9 could turn inside the Focke Wulfs, nearly blacking out sometimes with high G. Finally, in desperation and to get more height to fight, I put the aircraft into a steep climb and after what seemed a life-time found myself alone again."

This pilot flew an unknown mark of Spit IX, sqn is 92 RAF, date 16 apr 1943.
Anyway, I've seen more accounts of this climbing evasive, pilots all so far quite reliable.

Enjoy all

[Charge]

So those 190s had no energy left to zoom after foolishly trying to beat an IX in a turnfight.

Nice story.

-C+

[gripen]

Originally posted by Crumpp
FW-190A8 1.42ata@2700U/min
..
Altitude (feet)   2800
Maximum speed (at test alt.- mph)   348
Engine Horsepower (bhp at test alt)   1720

Actually the speed chart gives roughly 564 km/h (350 mph) at 2800 ft and the output chart gives 1760 ps (1736 hp) at 2800 ft with RAM.

Originally posted by Crumpp
Spitfire Mk IX Merlin 66 (+25)
..
Altitude (feet)   2800
Maximum speed (at test alt.- mph)   364
Engine Horsepower (bhp at test alt)   2050

The output is still wrong, the correct is about 2020 hp. And why not the JF275 data set? It did 374 mph at 2800 ft.

At 2800 ft the flat plate areas are following:

JF275: 4,92 for Cd and 4,77 for Cd0
JL165: 5,34 for Cd and 5,19 for Cd0
FW 190A-8: 5,14 for Cd and 4,78 for Cd0

The JF275 (without filling and polishing) does still better than the Fw 190A-8.

gripen

[Angus]

It was Neville Duke flying the Spitty.

[Crumpp]

The output is still wrong, the correct is about 2020 hp. And why not the JF275 data set? It did 374 mph at 2800 ft.

Actually the speed chart gives roughly 564 km/h (350 mph) at 2800 ft and the output chart gives 1760 ps (1736 hp) at 2800 ft with RAM.

According to the chart it is 2050hp but I will change it your numbers once again.

For the FW-190A8 you need to recheck that. The FTH for the BMW801D is only 1755 hp RAM and we are 2200 feet below that height.

Why not the J275?  Sure I would be glad to run it.

As soon as my questions about it are answered.  See above post's because I need some information on it otherwise I am just making a guess.

That is a totally different Spitfire however that never saw service in the European Theater.

With your new numbers the total drag runs out to be:

Spitfire Mk IX Merlin 66 Total Drag at 440fps - 1127.240025
FW-190A8 Total Drag at 440fps - 1102.340435

I will post the complete set of numbers later.

The JF275 (without filling and polishing) does still better than the Fw 190A-8.

The FW-190A8 is not filled and polished either.  If you would like a copy of the original German I would be glad to provide it.  It says "surface fixed and repainted" which is very different from filled and polished.  This has been covered before.

1.  Since you have not requested a copy of the original report that I offered you must either be:

a - Not reading my post's.
b - Deliberately attempting to inflame.

Which is it?

Crumpp

[Crumpp]

I put the aircraft into a steep climb and after what seemed a life-time found myself alone again."

Great Story Angus!

Some points that struck me.

1.  The confidence in which the 190 pilots closed and "mixed it up" with the Spitfires.  They did not make clumsy passes and then extend beyond visual range to reverse.  They got in tight and fought.

Anyway, I've seen more accounts of this climbing evasive, pilots all so far quite reliable.

2.  In a sustained climb the later Mk IX's ruled.

3.  Absolutely, Pilots are telling the truth about actual events.  However it is told from one person's perspective and may not neccessarily represent the total reality.

 

With the engine flat out I flew over the sea, twisting, turning, dodging, gaining a bit of confidence when I found my Spit 9 could turn inside the Focke Wulfs, nearly blacking out sometimes with high G. Finally, in desperation and to get more height to fight, I put the aircraft into a steep climb and after what seemed a life-time found myself alone again."

Empty sky syndrome, we talked about this phenomen before and is quite common amoung fighter pilots.  Without accounts from the otherside it is inconclusive.  Sounds like it erupted into a massive dogfight and he was lucky to survive.

I have some great stuff coming on JG2 who was flying FW-190's in North Africa around that time period.  When it gets here I will see if there is anything interesting noted on these dates.

Crumpp

[gripen]

Originally posted by Crumpp
According to the chart it is 2050hp but I will change it your numbers once again.

I wonder how you can read 2050 hp for +25 lbs from this chart?

Originally posted by Crumpp
For the FW-190A8 you need to recheck that. The FTH for the BMW801D is only 1755 hp RAM and we are 2200 feet below that height.

I wonder how you can read something else than 1760 ps (2700rpm and 1,42ata) at 2800 ft (853,44 m) from this chart?

Originally posted by Crumpp
Why not the J275?  Sure I would be glad to run it.

As soon as my questions about it are answered.  See above post's because I need some information on it otherwise I am just making a guess.

That is a totally different Spitfire however that never saw service in the European Theater.

Well, the JF275 had the Merlin 66 so it had standard wing tips ie the wing area was 242 sqft.

The main aerodynamic difference between the Spitfire IX and VIII was the tailwheel and the Spitfire VIII saw  service in Italy, I think even USAAF used it there

Originally posted by Crumpp
With your new numbers the total drag runs out to be:

Spitfire Mk IX Merlin 66 Total Drag at 440fps - 1127.240025
FW-190A8 Total Drag at 440fps - 1102.340435

Well, you don't need to calculate anything more with the JL165  data, remember your own words above:

"I am using the best available data I have and applying the same standard to both A/C."

The JL 165 had the largest flat plate area of all tested Spitfire IXs and for one reason or another you continously use it.

Originally posted by Crumpp
I will post the complete set of numbers later.

Just post relevant numbers (preferably flat plate area), posting the whole set is plain waste of bandwidth.

Originally posted by Crumpp
The FW-190A8 is not filled and polished either.

According to the chart in your source page it had "External surfaces: Filled + polished".

Originally posted by Crumpp
If you would like a copy of the original German I would be glad to provide it.  It says "surface fixed and repainted" which is very different from filled and polished.  This has been covered before.

1.  Since you have not requested a copy of the original report that I offered you must either be:

a - Not reading my post's.
b - Deliberately attempting to inflame.

Which is it?

It is c

c - get some web space and put the scanned picture there and link it directly to this thread so every one can check the thing.

gripen

[Crumpp]

According to the chart in your source page it had "External surfaces: Filled + polished".

Give me your email addy and I will send it too you.  If you can read German you will immediately see it.

As to your C - I don't have any web space and I am not putting all my document out for public consumption yet.

I am however being nice enough to offer it to you and others on this BBS.

Why do you constantly take a crappy attitude?  Are you in fear for some score in the game?

I have been trying to just have a discussion with you about this but you ALWAYS turn nasty the moment you shown to be mistaken about anything.

Lets review:

You call into question the Oswald factor calculations and were wrong.

It is not just JL275, I have posted calculations for EVERY Spitfire Mk IX listed on that site.  They all confirm David Lednicers data.  Even with the density and speed corrections the data does not change much at all.  The actual numbers vary but the results are the SAME.

I have made EVERY change you have requested.  The above calculations with ALL the changes you wanted!!  The conclusions remain the SAME.

All in all you are still running about 50 percent like the rest of us.

 

I wonder how you can read 2050 hp for +25 lbs from this chart?

I wonder how you don't!  AND I made the changes!

I wonder how you can read something else than 1760 ps (2700rpm and 1,42ata) at 2800 ft (853,44 m) from this chart?

I wonder how you don't! And I made the changes!

The main aerodynamic difference between the Spitfire IX and VIII was the tailwheel and the Spitfire VIII saw service in Italy, I think even USAAF used it there

Not according to every reference I have found on the Spitfire Mk VIII.  It was a non-pressurized version of the Mk VII with extended wings.  Later versions were fitted with the standard wings.  It was also the first version fitted with a teardrop canopy and a 6 bladed counter rotating propeller according to some sites.

It was never deployed to the Northern European Theater.  Many sites agree it was the best performing Spitfire version produced however by the time it came into service the Mk IX was well in place and it simply was not produced in any numbers.

The discussion was on David Lenicers data with your contention being the Spitfire always had less drag than the 190.  That is simply not true.  He was correct not you.

http://www.btinternet.com/~lee_mail/spitfire2.html

FW-190A8
Step A - Enter Aircraft dimension Data   
Wing area S (sq. feet) - 196.96
Airplane weight, lbs (as tested) - 9418
Wing span, ft - 34.45
   
Step B - performance #s at a known altitude   
   
   
Altitude (feet) - 2800
Maximum speed (at test alt.- mph) - 350
Engine Horsepower (bhp at test alt) - 1736
Stall speed (mph, at test alt)- 110

Drag total = 1112.002143@ 440 fps
parasitic drag = 981.8304509


Spitfire Mk IX Merlin 66 (+25)
Step A - Enter Aircraft dimension Data   
Wing area S (sq. feet) - 242
Airplane weight, lbs (as tested) - 7400
Wing span, ft - 36.1
   
Step B - performance #s at a known altitude   
   
   
Altitude (feet) - 2800
Maximum speed (at test alt.- mph) - 364
Engine Horsepower (bhp at test alt) - 2020
Stall speed (mph, at test alt) - 90

Total Drag = 1127.240025@ 440fps
parasitic drag = 1055.775


Crumpp

[Crumpp]

Here is JB 275's drag numbers at 2800 feet FTH (2020hp).


Total drag = 1051.19806 @ 440 fps
parasitic drag = 972.4078707

FW-190A8

Drag total = 1112.002143@ 440 fps
parasitic drag = 981.8304509


Again it has practically the same amount of force acting on a lot less mass.  It will only have an energy retention advantage when both planes are pulling several G's.



For the Spitfire Mk IX Merlin 61 we have in AH:

Step A - Enter Aircraft dimension Data   
Wing area S (sq. feet) - 242
Airplane weight, lbs (as tested) - 7480
Wing span, ft - 36.1
   
Step B - performance #s at a known altitude   
   
   
Altitude (feet) - 15400
Maximum speed (at test alt.- mph) - 380.5
Engine Horsepower (bhp at test alt) - 1565
Stall speed (mph, at test alt) - 90

Total Drag - 795.641828 @ 440 fps

Parasitic drag - 687.4074265

FW-190A5

Step A - Enter Aircraft dimension Data   
Wing area S (sq. feet) - 196.96
Airplane weight, lbs (as tested) - 9052
Wing span, ft - 34.45
   
Step B - performance #s at a known altitude   
   
   
Altitude (feet) - 15400
Maximum speed (at test alt.- mph) - 394
Engine Horsepower (bhp at test alt) - 1420
Stall speed (mph, at test alt) - 110

Total Drag -718.2845242@ 440 fps

Parasitic drag - 540.0383219


Crumpp

[Angus]

Without getting involved into the calculations:
"Not according to every reference I have found on the Spitfire Mk VIII. It was a non-pressurized version of the Mk VII with extended wings. Later versions were fitted with the standard wings. It was also the first version fitted with a teardrop canopy and a 6 bladed counter rotating propeller according to some sites. "

There were "Specialized" high alt versions of the Mk VIII, already in the med. I can check out dates, but I have no more detail about i.e. pressurized or not etc.
There were pressurised Spits, but what model, I do not know. There were also two-pilot  VIII and IX's actually.
None were supplied in the N European theater to my klnowledge, but some in the med, and the rest in SE asia. They may have been used to test some G-Suits down there actually, for they could pull very high G's for a long time, - more than any hardware available.
They were shipped to the med and se Asia because they were all "tropicalized" as far as I know. The filter design was far superior to the slowing-down Vokes filter.
And they did have a retractable tailwheel, and were cleared for 25 boost.
I never heard about the canopy or the counter-prop, but I'll check out from books as well as the ultimate roll rate of the final Spit series.
(digging for my book all over the house)
Anyway, best of luck and good night
Angus

[Crumpp]

Thanks Angus!

Good night bro.

Crumpp

[Nashwan]

Spitfire The History has a few details on JF 275's tests at 25 lbs.

It had a standard Rotol prop of 10 ft 9 in diameter (this rules out the contraprop) , standard wing with B armament (ie 2 20mm, 4 303s), takeoff weight 7700 lbs.

There's a photo of JF 275 as well, it doesn't have the bubble canopy. Of course, it might have been modified later, but I doubt it, there's nothing that I can see to indicate it was.

As to your C - I don't have any web space and I am not putting all my document out for public consumption yet.

If you've got any pics you do want to post, try picture hanger:

http://www.onpoi.net/ah/

Accounts are free, and for each picture you can chose "public" or "private". Private pics people cannot browse to, but you can still link to them from a forum.