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Kwiatos
05-05-2005, 02:44 PM
I wonder if acceleration of Fw 190 in Fb/PF is like should be? Every time when i'm taking off in Fw 190 i feel like it is a mule or sth. Is true that Fw190 has such bad acceleration comparing to other planes like Spitfire or Bf 109? I didnt make any test but these is so big diiference that no need timetest to feel it.

KGr.HH-Sunburst
05-05-2005, 03:31 PM
I remember one of my former squadmates asking the same question and he asked flugwerk (who build a replica of the A8) and their A8 was only slightly faster to get to take off speed and meters needed to get from the ground as our ingame FW190
which is correct i think as their A8 is lighter

so no i think ground acceleration is correct
and the distance needed to get airborne

3.JG51_BigBear
05-05-2005, 04:03 PM
Are you using 100% manual prop pitch? I think it accelerates pretty well when using that.

MEGILE
05-05-2005, 04:43 PM
The FW-190D9 leaves the P-51D20NA behind, no problem. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

faustnik
05-06-2005, 10:32 AM
Originally posted by Kwiatos:
I wonder if acceleration of Fw 190 in Fb/PF is like should be? Every time when i'm taking off in Fw 190 i feel like it is a mule or sth. Is true that Fw190 has such bad acceleration comparing to other planes like Spitfire or Bf 109? I didnt make any test but these is so big diiference that no need timetest to feel it.

The most important part of this question is "Spitfire or BF109". Compared to those two a/c the Fw190 accel is poor. Compared to the rest of the USAAF a/c it's fine. So, the Fw190 is not the problem.

Kwiatos
05-06-2005, 10:53 AM
I have some scan with comparison of initial acceleration different planes and from 1 place there is:
1. Spitifre 21
2. Spitfire MK XIV
3. BF 109 G !
4. Fw 190 !
5. Mustang III
6. Spitfire MK IX and XVI !
7. Meteor
8. Tempest II
9 Tempest V
10. Thunderbolt.

Kwiatos
05-06-2005, 11:47 AM
http://www.odyssey.dircon.co.uk/Spitfire9v190.htm

faustnik
05-06-2005, 11:52 AM
From Kwaitos' link:

Dive: The FW 190 is faster than the Spitfire IX in a dive, particularly during the initial stage. This superiority is not as marked as with the Spitfire VB.

The initial acceleration of the FW 190 is better than that of the Spitfire IX under all conditions of flight, except in level flight at altitudes where the Spitfire has a speed advantage.

robban75
05-06-2005, 02:59 PM
Originally posted by faustnik:
From Kwaitos' link:

Dive: The FW 190 is faster than the Spitfire IX in a dive, particularly during the initial stage. This superiority is not as marked as with the Spitfire VB.

The initial acceleration of the FW 190 is better than that of the Spitfire IX under all conditions of flight, except in level flight at altitudes where the Spitfire has a speed advantage.

Uh, oh. That doesn't match the results I get in the game. On the other hand, the Spit IX in that comparison didn't have a Merlin 66 did it?

Still, not even the mighty MkXIV had better dive acceleration than the Fw 190A.

See here for some in-game comparisons. http://forums.ubi.com/eve/forums/a/tpc/f/63110913/m/3561025813/p/2

robban75
05-06-2005, 03:18 PM
Originally posted by Megile:
The FW-190D9 leaves the P-51D20NA behind, no problem. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Try escaping the P-51 at 2000m in the D-9 '45.

The numbers below are not exact, but they still show the effect of the Fw 190 speed bug that has plauged it for over 6 months. The P-51D in the test had 50% fuel.

Spd - D-9 - P51
250 - ST - ST
300 - :5 - :6
400 - :21 - :20
500 - :48 - :41
600 - 1:54 - 1:31
610 - 2:18 - 1:42
620 - N/A - 2:00
630 - N/A - 2:17

The D-9 is 33(!)km/h too slow at this altitude.

VW-IceFire
05-06-2005, 06:59 PM
Originally posted by robban75:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by faustnik:
From Kwaitos' link:

Dive: The FW 190 is faster than the Spitfire IX in a dive, particularly during the initial stage. This superiority is not as marked as with the Spitfire VB.

The initial acceleration of the FW 190 is better than that of the Spitfire IX under all conditions of flight, except in level flight at altitudes where the Spitfire has a speed advantage.

Uh, oh. That doesn't match the results I get in the game. On the other hand, the Spit IX in that comparison didn't have a Merlin 66 did it?

Still, not even the mighty MkXIV had better dive acceleration than the Fw 190A.

See here for some in-game comparisons. http://forums.ubi.com/eve/forums/a/tpc/f/63110913/m/3561025813/p/2 </div></BLOCKQUOTE>
I think the Spitfire IX used in the tests was one of the early models with a Merlin 61 engine (a F.IX). It does say that at all altitudes where the Spitfire has speed advantage does it have acceleration advantage...interestingly enough the LF.IX should in theory have speed advantage at nearly all altitudes.

I think the FW190A was still heavier than the Spitfire XIV...but I'll have to double check that and I'm sure that factored into the impressive dives. Spitfire couldn't catch a FW190 in a dive but could keep up enough to catch them at the bottom...

robban75
05-07-2005, 03:51 AM
Originally posted by VW-IceFire:
I think the Spitfire IX used in the tests was one of the early models with a Merlin 61 engine (a F.IX). It does say that at all altitudes where the Spitfire has speed advantage does it have acceleration advantage...interestingly enough the LF.IX should in theory have speed advantage at nearly all altitudes.

I think the FW190A was still heavier than the Spitfire XIV...but I'll have to double check that and I'm sure that factored into the impressive dives. Spitfire couldn't catch a FW190 in a dive but could keep up enough to catch them at the bottom...

There's not enough info on that Fw 190 used in the comparison. Did they run it at 1.35 ata or 1.42 ata? I think it's safe to say that they didn't use 1.65 ata. At that boost not even the XIV was fast enough to catch it.

jurinko
05-07-2005, 04:03 AM
Eric Brown wrote, that the take-off for Fw 190 is much shorter than for Spitfire but dunno which mark.

robban75
05-07-2005, 04:20 AM
Originally posted by jurinko:
Eric Brown wrote, that the take-off for Fw 190 is much shorter than for Spitfire but dunno which mark.

That could be because of the wider landing gear of the Fw 190, making it more stable on take off and less sensetive to torque. Meaning that full power was avalible more early than on the Spitfire with its narrow landing gear. The Spitfire in the game has no torque so this doesn't pose any problems for it.

VW-IceFire
05-07-2005, 08:11 AM
Originally posted by robban75:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jurinko:
Eric Brown wrote, that the take-off for Fw 190 is much shorter than for Spitfire but dunno which mark.

That could be because of the wider landing gear of the Fw 190, making it more stable on take off and less sensetive to torque. Meaning that full power was avalible more early than on the Spitfire with its narrow landing gear. The Spitfire in the game has no torque so this doesn't pose any problems for it. </div></BLOCKQUOTE>
Yeah I suspect thats probably it. If you slowly throttle up in a Spitfire it takes quite a bit of time to get rolling. You really aren't supposed to slam the throttle to 100%.

hop2002
05-07-2005, 08:28 AM
Eric Brown wrote, that the take-off for Fw 190 is much shorter than for Spitfire but dunno which mark.

In Wings of the Luftwaffe Brown says of his flight in a 190 A4:

"using 2700 rpm and 1.6 ata boost, found the run to be much the same as that of the Spitfire Mk IX"

The Spitfire IX take off runs varied from 480 yards for the LF IX to 500 for the F IX, compared to up to 650 yards for a tropicalised Mk V.

robban75
05-07-2005, 08:37 AM
Originally posted by hop2002:
In Wings of the Luftwaffe Brown says of his flight in a 190 A4:

"using 2700 rpm and 1.6 ata boost, found the run to be much the same as that of the Spitfire Mk IX"



1.6 ata? In the A-4? That would require C3 injection, wouldn't it? http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif

Hunde_3.JG51
05-07-2005, 09:49 AM
From the FW-190A-3 Faber test running at 1.42:

"The takeoff run is approximately the same as the Spitfire Mk.IX" (likely Merlin 61, not 66).

We cannot recreate that in-game (no Merlin 61 Mk.IX) so the Faber A-3 test can't be used as a guide unfortunatley.

carguy_
05-07-2005, 10:47 AM
hehehe Coastie can say something about it.He followed me in a dive and shot me down.He in IX me in A9.

As for comapring with Me109,it had always better acceleration ever since I remember.Additionally you can compare real/ingame fuel consumption.Nothing is ok in this department.

faustnik
05-07-2005, 11:00 AM
Originally posted by robban75:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by hop2002:
In Wings of the Luftwaffe Brown says of his flight in a 190 A4:

"using 2700 rpm and 1.6 ata boost, found the run to be much the same as that of the Spitfire Mk IX"



1.6 ata? In the A-4? That would require C3 injection, wouldn't it? http://forums.ubi.com/images/smilies/16x16_smiley-indifferent.gif </div></BLOCKQUOTE>

Yes, something is wrong there. 2700rpm would indicate 1.42 atas.

hop2002
05-07-2005, 11:43 AM
1.6 ata? In the A-4? That would require C3 injection, wouldn't it?

I don't know, but the British did fairly routinely exceed the posted limits in their testing of German aircraft.

I think the rational was to test against what the German aircraft would be doing soon, rather than testing what they used to do, because captured aircraft were often quite old.

Brown didn't actually fly an FW 190 until Feb 1944, so it's easy to see why the RAF would want to overboost to keep up with any increases in boost the Germans would be using.

Brown is quite clear about the settings, saying 2700 rpm, 23.5 psi, 1.6ata for takeoff, then saying he throttled back to 1.45 ata.

Of course, he might simply be mistaken.

p1ngu666
05-07-2005, 12:08 PM
c3 injection was to stop detination wasnt it?

british fuel was perhaps abit better, so it could run with higher boost without injection

robban75
05-07-2005, 12:37 PM
Originally posted by p1ngu666:
c3 injection was to stop detination wasnt it?

british fuel was perhaps abit better, so it could run with higher boost without injection

I believe C3 fuel was ~97 octane. The Germans used C3 injection when operating at 1.65 ata.

faustnik
05-07-2005, 02:38 PM
The 801D would need C3 injection to run 1.65 ata. The A4 ran 1.42 ata at 2700rpm. Running that high a boost without cooling would probably fry the engine, and Brown mentioned no problem.

I wonder if that was the A4 captured in the Med? It was most likely rated at 1.35 ata and used in the Jabo role.

hop2002
05-07-2005, 03:38 PM
According to Brown it was Pe882, an Fw 190A4/U8, that landed by mistake at West Malling (Kent) in April 43.

faustnik
05-07-2005, 03:45 PM
The A4/U8 is a long range Jabo similar to the G1. By April '43 odds are that it was uprated to 1.42 ata (3 minute WEP). It would normally be slightly slower than the standard fighter variants with the ETC rack and long range equipment, but, I bet the RAF took as much stuff of as possible for testing.

BTW, nice of the Fw190 pilots to keep landing their planes at RAF bases. I'm sure the RAF pilots really appreaciated it! http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

hop2002
05-07-2005, 03:48 PM
Faustnik, looking again at the thread on Butch's board about 1.42 ata in the A3, there's some info on 1.65 ata.

Wastel says that during the trials of 1.65 ata, a couple of the test aircraft had the C3 injection installed wrongly, and completed the test programme at 1.65 ata without it, but for safety's sake C3 was required for service use of 1.65 ata.

Wastel also says that 1.65 ata was authorised on Jabo aircraft in mid/late 43, on fighters in early 44.

hop2002
05-07-2005, 03:53 PM
BTW, nice of the Fw190 pilots to keep landing their planes at RAF bases. I'm sure the RAF pilots really appreaciated it!

Yes, PE882 landed at W Malling on 17th April 43, then another 190 landed at Manston 20th May 43, and a third 20th June 43.


The A4/U8 is a long range Jabo similar to the G1. By April '43 odds are that it was uprated to 1.42 ata (3 minute WEP). It would normally be slightly slower than the standard fighter variants with the ETC rack and long range equipment, but, I bet the RAF took as much stuff of as possible for testing.

I've seen (iirc) some people claim the RAF misidentified it, and it wasn't a U8, but what variant they think it was, I can't remember.

Brown does note it had "provision for two bomb carriers beneath the wings" which suggests they weren't fitted, but obviously it's too vague to draw conclusions from, and even if they weren't fitted when Brown flew it, they may have been for other tests.

faustnik
05-07-2005, 03:59 PM
Hop, the A4 would have to be modified for 1.65 ata. Even if it could survive without nasty overheat issues, which Brown never mentioned, the RAF would have had to modify the aircraft. It seems much more likely that at 2700 rpm the A4 was at 1.42 ata boost (which would still give it all the performance abilities Brown mentions).

The 2 "bomb carriers" under the wings would be the attachment points for long range drop tanks used by the U8 variant.

CUJO_1970
05-07-2005, 06:04 PM
PE882's externals stores racks were removed and faired over by the time Eric Brown flew it.

CUJO_1970
05-07-2005, 06:19 PM
According to Phillipe Willaume, the BMW801D was fully rated with chromed exhausts by mid-1942.

Then the supercharger was modified(with different drive ratios I believe) and the exhaust pipes were re-designed.

All of this without any changes of engine designation so it can get confusing.

I believe the main exhaust pipe re-design was the pipes from the bottom two cylinders of the rear row. It seems they were re-shaped from the "rectangular" shaped pipes of the other cylinders, enlarged and possibly re-routed to exhaust directly beneath them, and not out of the cooling "gills" in the side of the cowling.

Unfortunately, this comes from pieces of several different sources and you have to put it together like a puzzle.

I'd love to see it all together in one place, but that's why it is so difficult to research certain features of German aircraft. (At least for me)

I think some of the guys in Europe have the complete documentation.

hop2002
05-07-2005, 08:23 PM
Hop, the A4 would have to be modified for 1.65 ata. Even if it could survive without nasty overheat issues, which Brown never mentioned, the RAF would have had to modify the aircraft.

I'm not sure it would.

The RAE report on Faber's A3 says it should be capable of 1.5 ata at sea level (they believed that was the full rating, at least for a time, or that the rating would soon be increased to 1.5ata)

AFAIK, the changes on the supercharger of the 190 came in during the A4 production, and I believe they would allow 1.65 ata (actually it was limited to about 1.6 ata in low gear, 1.65 in high)

If the supercharger is capable of providing the pressure, the only other requirements are that the boost control (if fitted) doesn't prevent the pressure, and that's just an adjustment, and that the engine can run at that pressure.

I think it would have required fairly simple adjustments for the RAF to get an A4 running at 1.65 ata.

As to the engine trouble, Brown used it only for takeoff, afaik, which would indicate a very short period.

Also, I've got a bit of a report by the squadron leader of 485 squadron (can't make out his name from the signature) of a test flight he made in an Fw 190, PN999 (A5 U8, I believe). The letter is dated late August 43, and I think the flight was shortly before that.

He says he only used cruise settings, and says he experienced no engine troubles, but that he had been "warned about an extremely rough engine", presumably at full power.

The RAF had these aircraft on test, and I don't think they'd have been as worried about engine trouble as the service operators.

faustnik
05-07-2005, 10:18 PM
Originally posted by hop2002:

The RAF had these aircraft on test, and I don't think they'd have been as worried about engine trouble as the service operators.

That's certainly true, they would care. I think the greater likelyhood is still 1.42 ata maximum for that A4.

VW-IceFire
05-08-2005, 03:49 PM
Pingu, Oldman, and myself tested the Bf-109G-6 Late, FW190A-8 and Spitfire VIII today. More will come from those tests but we did some acceleration (right from standstill) and found the 109 accelerated best from the start, with the FW190 in close second, then the VIII gains and overtakes...with the 109 close behind and the FW190 in the dust. Eventually the 190 passed us in a level speed run....so it does appear that its acceleration is behind that of the Spitfire and 109...more testing required.

Also found that the FW190 rapidly pulls away in a dive and that the zoom climb from both is nearly the same...the FW190 being a bit better from a very high speed pullout.

OldMan____
05-08-2005, 07:55 PM
Pingu and I conducted some more testa after you left Ice. Another good one. P51D vs P38J. Very start the P51 pulls ahead. Than about 250 kph on P38 gains terrain. At about 400 kph P51 start outrunnign P38 again.

FW190D 45 outaccelerates FW190D44 by quite a noticiable margin.

Also Ice.. remeber that pull out from 800 kph in my FW was almost a miracle since I made it keep stable down to 5kph .. usually FW loose balance as soon as they reach 70 kph. Spit kept much more stable till very end of every pull out test.


And the MOST interesting. Up to 300 kph.. FW190A4 outaccelerates FW190A8!!!!

TX-Gunslinger
05-09-2005, 12:04 AM
Originally posted by OldMan____:
Pingu and I conducted some more testa after you left Ice. Another good one. P51D vs P38J. Very start the P51 pulls ahead. Than about 250 kph on P38 gains terrain. At about 400 kph P51 start outrunnign P38 again.

FW190D 45 outaccelerates FW190D44 by quite a noticiable margin.

Also Ice.. remeber that pull out from 800 kph in my FW was almost a miracle since I made it keep stable down to 5kph .. usually FW loose balance as soon as they reach 70 kph. Spit kept much more stable till very end of every pull out test.


And the MOST interesting. Up to 300 kph.. FW190A4 outaccelerates FW190A8!!!!


Now it all makes sense.

The last 6 months have been Hell. Thanks guys for doing all that testing, at least I know I'm not completely digressing as a pilot. For a while I thought I'd caught some sinister illness http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Now thanks to you, I'm sure that I'm only mildly ******ed http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Sure do wish Youss would put acceleration curves in IL2Compare.

Everything that I read, even from RAF sources, is that the Spit IX gave the RAF parity, not superiority over the FW-190A when it was introduced.

Anyway, thanks.......

S~

hop2002
05-09-2005, 10:00 AM
Pingu, Oldman, and myself tested the Bf-109G-6 Late, FW190A-8 and Spitfire VIII today. More will come from those tests but we did some acceleration (right from standstill) and found the 109 accelerated best from the start, with the FW190 in close second, then the VIII gains and overtakes...with the 109 close behind and the FW190 in the dust. Eventually the 190 passed us in a level speed run....so it does appear that its acceleration is behind that of the Spitfire and 109...more testing required.

I don't see much wrong with that, apart from the Fw190 doing well from standstill (although even that's possible. You were on the ground to begin with? If so, it eliminates induced drag, which would be worst of all on the 190)

Around climb speed (150 - 200 mph) the 109 and Spit should be doing much better than the 190, the 190 should begin to gain an advantage as the speed gets higher.

Here's a simple graph to illustrate the point:
http://www.onpoi.net/ah/pics/users/282_1093216393_rocspeedspit190.gif
(It's not supposed to be accurate, just illustrate the general principle. The drop in climb/acceleration with speed is not linear, but not that far off either)

The left colum shows climb rate, but could equally show acceleration, because climb rate and acceleration at any particular speed are directly proportional.

Simply, the better climbing plane accelerates faster at climb speed, the faster plane accelerates faster at high speed. Somewhere the points cross, and that depends on both the climb rate advantage and the speed advantage (of course, if the better climbing plane is also faster, the points don't cross, and it accelerates faster at all speeds (above climb speed anyway).

Note that all this is altitude dependant, as both climb rate and speed vary with altitude, so will acceleration. For example, the Spitfire IX climbs better than the 190 at almost (all?) altitudes, but is slower at most. However, at some alts the Spit is both faster and better climbing, so you need to work out figures for any particular altitude.

faustnik
05-09-2005, 10:13 AM
Hop,

I understand your point and intention. I don't care for the fact that you have created a graph based on pure speculation and labeled it with actual aircraft types. People would easily take this as factual. Maybe a "plane X", "plane Y" label would be better. You certainly make it clear that the graph is conjecture, but, others will certainly try to present it as fact.

robban75
05-09-2005, 12:17 PM
The FW 190 high speed climb does not apply when the VIII and IXc is in pursuit.

Climb comparison Fw 190A-6 vs Spitfire MkVIII at 480km/h.

In time to alt and m/sec

A-6

1000 - 1:43 - 9.7
2000 - 3:30 - 9.3
3000 - 5:30 - 8.3

VIII

1000 - 1:54 - 8.8
2000 - 3:28 - 10.6
3000 - 4:51 - 12.0

quiet_man
05-09-2005, 01:52 PM
@robban75
still in testing mod?

try the ones below I did with earlier IL2 version, they show an FM limitation with disadvantage for 190
I think the missing inertia effect Oleg wants to include in 4.0 FM


<pre class="ip-ubbcode-code-pre">
Tests with 50% Fuel, standard weapons, multiplayer host, no cockpit, over ocean
all Tests where very stable (2-3 tries for training, all following tries where within +/-10kph)

1. dive accel. at very slow speed without engine
all planes should accel near 1g

divespeed (kph) at impact, starting at 500m with 150kph
Yak3U 360
109G6 360
190A5 360
La5FN 360
109E4 360

all planes are accellerating the same at low speed and that is right.


2. deaccel near Vmax. when engine is cut.
planes with ~same engine power have ~same drag at this speed
so the plane with higher weight will lose less speed for at least some seconds.

start-speed (kph) = Vmax, end-speed (kph) after 15 seconds at 0% engine
Yak3U 590-450
109G6 530-400
190A5 560-410
La5FN 580-420
109E4 490-350


3. deaccel at slow speed (<300kph) when engine is cut.
heavier planes should have a much higher lose of speed

start-speed (kph) = 350, end-speed (kph) after 15 seconds at 0% engine
Yak3U 350-280
109G6 350-280
190A5 350-280
La5FN 350-280
109E4 350-270


drag effect for speed seams to be reverse from reality

quiet_man
</pre>

quiet_man

robban75
05-09-2005, 03:18 PM
I'm of to bed, I'll read it throrughly tomorrow! http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

Buzzsaw-
05-09-2005, 03:59 PM
Salute

Since the later model Spitfire IX's and VIII's with the Merlin 66 had a better climbrate, even at +18 boost, than the 190A's, there is every reason to expect that the Spitfire would have better acceleration at low speeds. At high speeds, ie. close to the Spitfire's maximum velocity, the 190A's have better acceleration.

Even the 190D should not have a better acceleration at low speeds than the Spitfires, since as tests show, the Spitfire IX's and VIII's with Merlin 66's had climbrates at sea level of between 4400-4600 fpm or 22.35 - 23.37 meters per second. However, as speeds increased, as the 190D's had a considerable advantage in top speed, it would gain a definite acceleration advantage as the Spitfire approached its max V.

It is important to remember that the tests between Faber's A3 and the Spitfire IXF were undertaken with the Spitfire running at +12 boost. At that level of forced induction, the Merlin 61 equipped IXF only had a climbrate of 3860 fpm or 19.6 meters per second.

Using the results for the IXF and then trying replicate them in IL-2/FB/PF with a +18 boost IXLF or VIII is not going to give a similar result since none of the game's aircraft run at +12 boost. Also, the 190A3 was run by the British testers at 1.42 ata boost, whereas the 190A4 we have in the game is based on a 1942 model, running at 1.35 boost.

Details at Mike Williams Spitfire Site:

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

OldMan____
05-09-2005, 07:09 PM
Fresh new acc tests.

Two time measures. One from 300kph to 400kph, and other from 300kph to 530 kph. At se level, 50% fuel. This I think are reasonable combat usefull situations


Bf109 K4 - 13,7 s - 41,1 s
FW190A5 - 14,3 s - 53,5 s
FW190D9 45- 13,2 s - 43,1 s
P38 J - 12,8 s - 53,8 s
FW190A9 - 14,2 s - 45,5 s
Me 262A2 - 24 s - 37,1 s
Corsair D - 13,1 s - 53,6 s
Spit 9 LF - 12,4 s - 80 s

And when we think we already have our champions..

LA 7 - 9,8 s - 34,3 s



So basically. Spit is hell at beggining.. but is very slow after 500, same for P38 J. Dora is pretty fast in all situations, same for 109K4. Me26 accelerates VERY slowly at begginign.. but contrary to other planes it accelerates each second faster as speed progresses.


And LA 7 justleave anything on dust..!!

OldMan____
05-09-2005, 07:42 PM
Updated

Bf109 K4 - 13,7 s - 41,1 s
FW190A5 - 14,3 s - 53,5 s
FW190D945- 13,2 s - 43,1 s
P38 J - 12,8 s - 53,8 s
FW190A9 - 14,2 s - 45,5 s
Me 262A2 - 24,0 s - 37,1 s
Corsair D - 13,1 s - 53,6 s
Spit 9 LF - 12,4 s - 80 s
LA 7 - 9,8 s - 34,3 s
Me163 - 3,8 s - 8,44 s
FW190A4 - 14,1s - 59 s
P63 - 10,9 s - 41,1 s
Ki84c- 11,3 s - 42,7 s
P51D - 13,0 s - 51,1 s
Ta152 - 11,5 s - 40,3 s


so .. take your own conlusions.. I am to tired for doing that .

Hunde_3.JG51
05-09-2005, 08:31 PM
I see only 3 prop driven aircraft took 14+ seconds in the the 300-400km/h acceleration test.

1. FW-190A-4
2. FW-190A-5
3. FW-190A-9

In Faber's test the FW-190A-3 out-accelerated all planes (Spit V., Spit F.IX Merlin 61, P-51A, P-38F, & Typhoon), with the exception of the Griffon engined Spitfire which was either a prototype or a Spitfire XII which is a mid-'43 aircraft compared to 190A-3 (an early '42 aircraft). The 190's better acceleration in the test was often more pronounced at low speed, which is the opposite of what we see here.

Also, the planes tested here are more powerful than the ones in Faber's test, but the A-5 and A-9 were considerably faster than the A-3 as well, at least at lower altitudes.

Anyway, just an observation. I don't know if it is right or wrong but it still seems weird to me how long it takes the 190A to get off the runway compared to almost every other aircraft. I seriously doubt anything will be changed anyway, but it is still interesting to look at/talk about. And either way it is no big deal.

Thanks guys for the effort you put in, much appreciated.

p1ngu666
05-09-2005, 09:13 PM
Originally posted by Hunde_3.JG51:
I see only 3 prop driven aircraft took 14+ seconds in the the 300-400km/h acceleration test.

1. FW-190A-4
2. FW-190A-5
3. FW-190A-9

In Faber's test the FW-190A-3 out-accelerated all planes (Spit V., Spit F.IX Merlin 61, P-51A, P-38F, & Typhoon), with the exception of the Griffon engined Spitfire which was either a prototype or a Spitfire XII which is a mid-'43 aircraft compared to 190A-3 (an early '42 aircraft). The 190's better acceleration in the test was often more pronounced at low speed, which is the opposite of what we see here.

Also, the planes tested here are more powerful than the ones in Faber's test, but the A-5 and A-9 were considerably faster than the A-3 as well, at least at lower altitudes.

Anyway, just an observation. I don't know if it is right or wrong but it still seems weird to me how long it takes the 190A to get off the runway compared to almost every other aircraft. I seriously doubt anything will be changed anyway, but it is still interesting to look at/talk about. And either way it is no big deal.

Thanks guys for the effort you put in, much appreciated.

hm wasnt faber plane running higher ata than normal one? but then again later a series was powerful or moreso than the one tested.
id agree its not good for 190, 190 is fast in a straight line and decent accel at higher speeds, bit better in dive and good roll

vs the spitfire, a 190 shouldnt attempt to climb much, infact it should go level or dive, spitfire is better in climb even at med-high speeds.
id also say the g6late, which is just abit worse than a spitfire in most areas, is better than 190 http://forums.ubi.com/images/smilies/16x16_smiley-sad.gif
190 is abit like ki61, p38 imo, theres something wrong with them, but they reach the right numbers mostly

p1ngu666
05-09-2005, 09:16 PM
oh just curious, anyone got lift produced by 190 wing compaired to 109(slats in) and or spit?
could be the game engine isnt correct in its use of thrust for climb vs lift the wing makes

OldMan___
05-10-2005, 05:41 AM
Doea anyone have chartsa bout acceleration so I can try to duplicate their results and send to 1C ...(question mark ismission in my keyboard)


Also that proves that the ROCKET acceleration of Bf109 is BULL EXCREMENT! Is is not even among the fastest ones from 300-400 kph.


This acceleration issues are really important. Since they represent the E trade among drag and engine so they explain why FW is so inferior to Spit in game. In fact few things are more important than acceleration. And Probably SPIT 14 will accelerate something closer to LA7 when it comes by.



Also it seems that LA7 has much lower drag than other planes since it just triples time when from 300-400 to 300-530, while other planes multiply it by 4 or more.


Aso as side effect during testting. I started the flight at 500 meters and dove to level holding speed down as much as I could. SURPRISE!! Bf109 is one of the worst BRAKERS!! Onlt FW is orse in holding speed down. The american planes were the ones in which I could brake more effectively.

I dont have data on this, but will perform easurements as soon as I have time.

Blutarski2004
05-10-2005, 10:35 AM
Just finished reading "Wolfpack Warriors" by Roger Freeman. In it he quotes a 56FG pilot discussing the utility of the FW190's superior acceleration in comparison to that of the P47 in a most interesting situation - one I had not previously considered.

The US pilot considered the P47 was better than the FW190 in a turn. But he had run into German pilots who would turn very tightly up to the stall speed point, then loosen up the turn and use the 190's superior acceleration to make up any lost distance. In the hand of such a pilot, the US pilot felt the FW190 was actually more dangerous (his perspective) in a turn fight than the ME109.

Interesting.

faustnik
05-10-2005, 11:25 AM
Originally posted by Buzzsaw-:
Salute

Since the later model Spitfire IX's and VIII's with the Merlin 66 had a better climbrate, even at +18 boost, than the 190A's, there is every reason to expect that the Spitfire would have better acceleration at low speeds. At high speeds, ie. close to the Spitfire's maximum velocity, the 190A's have better acceleration.

Buzzsaw,

I understand what you are saying about the Spit having an acceleration advantage at its best climbspeed but, why do you think that the Fw190 will only gain an advatage near the Spitfire's maximum velocity? As speed increases, the Spitfires climb advatage would drop rapidly shifting the advatage towards the Fw190.

robban75
05-10-2005, 11:54 AM
I'd like to have an A-5 that will run at 1.65ata boost. It would be fun to have in-game. Almost as fast a Dora, but with a better climbrate. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

faustnik
05-10-2005, 12:10 PM
Shouldn't the A5s and A6s with NE boost be running 1.65ata? These should be the best performing BMW801D equipped Fw190s, right?

robban75
05-10-2005, 12:14 PM
Originally posted by faustnik:
Shouldn't the A5s and A6s with NE boost be running 1.65ata? These should be the best performing BMW801D equipped Fw190s, right?

Yes, but they are not. Looking at this http://pages.sbcglobal.net/mdegnan/_images/fw190_A5_speed.gif A-5 speed chart it did 577km/h at 1.42 ata. At 1.65 ata I'm guessing the speed must at least be in the low 600's.

MEGILE
05-10-2005, 12:15 PM
Robban, Quick Question.

Have you done any speed tests on the FW-190A5 and A6?
I was wondering which is the fastest and by how much? http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

thanks

robban75
05-10-2005, 12:25 PM
Originally posted by Megile:
Robban, Quick Question.

Have you done any speed tests on the FW-190A5 and A6?
I was wondering which is the fastest and by how much? http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

thanks

They are virtually the same. They both top out at 579km/h at sealevel. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

p1ngu666
05-10-2005, 12:25 PM
Originally posted by Megile:
Robban, Quick Question.

Have you done any speed tests on the FW-190A5 and A6?
I was wondering which is the fastest and by how much? http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

thanks

think there identical, apart from a5 has mgff and a6 has mg151 outer cannons

didnt know a5-6 had higher boost in later? service but id like them http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

faustnik
05-10-2005, 12:46 PM
Well, it would have been more useful to give us a late 1942 production Fw190A5 without NE cooling but with 1.42 ata. Actually, this is waht we have now in terms of performance. The 1943 A6 should have NE boost and 1.65 ata making it the best performing Fw190A (BMW801D) in the sim. Without outer guns, the 1.65 A6 would be very fast and a godd dogfighter. This would make both planes more useful for mission creation.

It's like the Spit IX series. The 1943 "C" we have with +18 boost is great but, give us the 1944 "E" with +25 boost. We would get much better use out of the series.

p1ngu666
05-10-2005, 01:10 PM
hm, imo should be added as extra planes
a5 late
a6late
ixc late
ixe late

do we have a remove outer guns loadout for a5-6?

OldMan____
05-10-2005, 01:19 PM
A light FW190 (A6.. maybe without outer guns) with 1.65 ata would be ASTONESHING! Acceleration would probably be about Dora Level.

We can simmulate this by making all other planes carry 250 kg bombs! :P

Kurfurst__
05-10-2005, 01:40 PM
Originally posted by hop2002:
The left colum shows climb rate, but could equally show acceleration, because climb rate and acceleration at any particular speed are directly proportional.

Simply, the better climbing plane accelerates faster at climb speed, the faster plane accelerates faster at high speed.



It seems Hop just doesn`t get climb is dependent on LIFT by a large margin. A simply example, make the Spitfire a biplane. It has now twice the wing area with massively higher rate of climb because of the lift area that doubled... would acceleration also double? Of course not, why would it, there is only extra drag and weight on the plane...

Look at actual examples, the Fiat Cr 42s were not known to be particularly fast, but with their biplane design, they easily matched the climb rate of the early Spits/109s even with much weaker engines.

OldMan____
05-10-2005, 01:50 PM
Originally posted by Kurfurst__:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by hop2002:
The left colum shows climb rate, but could equally show acceleration, because climb rate and acceleration at any particular speed are directly proportional.

Simply, the better climbing plane accelerates faster at climb speed, the faster plane accelerates faster at high speed.


That`s absolute nonsense, made up by Hop who`s newest aganda seems to be to propagate that his beloved Spitfire does everything, in this case, acceleration than any other plane... a claim completely unsupported by any factual data.

Now the claimed proportional relation between climb speed and acceleration... completely silly. It seems Hop just doesn`t get climb is dependent on LIFT by a large margin. A simply example, make the Spitfire a biplane. It has now twice the wing area with massively higher rate of climb because of the lift area that doubled... would acceleration also double? Of course not, why would it, there is only extra drag and weight on the plane...

Look at actual examples, the Fiat Cr 42s were not known to be particularly fast, but with their biplane design, they easily matched the climb rate of the early Spits/109s even with much weaker engines. </div></BLOCKQUOTE>

do you even think someone is paying attention on him with this kind of argument?

Just remember.. by some guys physics.. wing load is EXTREMELY important in vertical zoom climb and Acceleration rules climb performance

faustnik
05-10-2005, 02:16 PM
Kurfurst,

Wait a minute here. If you are going to tear down Hop's theory at least present one of your own.

What are the factors influencing fighter acceleration?

OldMan____
05-10-2005, 02:44 PM
Originally posted by faustnik:
Kurfurst,

Wait a minute here. If you are going to tear down Hop's theory at least present one of your own.

What are the factors influencing fighter acceleration?

is not about that he is speaking about. He say that acceleration is not DIRECTLY proportional to climb. You may climb well without a good acceleration. Lift is more important, uynless you are talking about a rocket.

A F1 car accelerates better than a mustang, but of course it does not have a better climb rate.

hop2002
05-10-2005, 03:07 PM
That`s absolute nonsense, made up by Hop who`s newest aganda seems to be to propagate that his beloved Spitfire does everything, in this case, acceleration than any other plane... a claim completely unsupported by any factual data.

Straw man again Isegrim.

I didn't say "any other plane", in fact I'm not even claiming better than the 190 at all speeds, just at some speeds.


It seems Hop just doesn`t get climb is dependent on LIFT by a large margin.

Climb is not dependant on lift.

Well, no more than level flight is.

Lift causes induced drag, and that has an effect on excess thrust, but the effect is exactly the same in climb or level flight.

In a normal climb, lift = weight, exactly the same as in level flight.

Planes climb because they increase their attitude (point the nose up), not because lift is pushing them up.

See for example:


For all practical purposes, the wing's lift in a steady state normal climb is the same as it is in a steady level flight at the same airspeed. Though the airplane's flightpath has changed when the climb has been established, the angle of attack of the wing with respect to the inclined flightpath reverts to practically the same values, as does the lift.
http://avstop.com/AC/FlightTraingHandbook/ForcesinClimbs.html


In level flight the four forces Lift, Thrust, Drag and Weight must add up to zero. This is demonstrated in the animated graphic to the right.

To add vectors they are simply laid out tip to tail. The sum of the four vectors is zero.

The same must be true in a steady climb (ie. no state of acceleration.)
http://142.26.194.131/aerodynamics1/Performance/climb.html



Because AOA and lift are not very relivent to climb rate.

Climb rate is a function of drag and power.

Hitech, from Hitech Creations (Aces High)
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=128024&highlight=climb+AND+lift


(The thread above is an interesting one, because it covers many of the same points about climb/acceleration at different speeds, especially between the Spit and Fw 190)


To calculate an aircraft's climb angle, take the inverse sine of the excess thrust divided by the aircraft's weight. Climb Angle = Sin-1(Thrust-Drag/Weight)

......

With all this talk of excess thrust, one might ask, what does lift have to do with climbs? Many pilots wrongly think it is excess lift that makes an aircraft climb.

(snip bit about excess lift helping during the pitch up, which applies to Oldman's argument)

......

One can summarize by saying excess lift deflects the flight path upward and excess thrust sustains the flight path once deflected.
http://www.erau.edu/er/newsmedia/articles/wp6.html


That's the point, lift is only important during the pitch up into the climb, not the climb itself (and that's why the Spitfire enters the climb with less losses than the 190)

The only difference between lift in a climb and level flight is that you need slightly less lift in a climb, not more, but the difference is only very slight at normal climbing angles for WW2 fighters.

For those whose maths is up to it, Funked's definition of climb rate/acceleration:


* = multiplicaton
d[]/dt = differentiation operator, e.g. df/dt = first derivative of f with respect to time.
t = time
E(t) = energy as a function of time.
P(t) = excess power as a function of time.
v(t) = TAS as a function of time.
h(t) = height as a function of time.
m = mass
g = gravitational constant

Total energy of the airplane, assuming the mass of the aircraft is not changing.
E(t) = 0.5 * m * v(t) * v(t) + m * g * h(t)

P(t) is defined as dE(t)/dt. The definition of power is the rate of change of energy with respect to time.

Therefore:

P(t) = d( 0.5 * m * v(t) * v(t) + m * g * h(t) )/dt
P(t) = m * v(t) * dv(t)/dt + m * g * dh(t)/dt

dv(t)/dt is defined as acceleration.
dh(t)/dt is defined as rate of climb.

Assuming level flight, dh(t)/dt = 0
P(t) = m * v(t) * dv(t)/dt + m * g * 0
P(t) = m * v(t) * dv(t)/dt
dv(t)/dt = P(t) / (v(t) * m)
That is, at any instant in time, acceleration in level flight is equal to excess power divided by the product of mass and TAS.

Assuming constant speed flight, dv(t)/dt = 0
P(t) = m * v(t) * 0 + m * g * dh(t)/dt
dh(t)/dt = P(t)/(m*g)
That is, at any instant in time, the sustained rate of climb is equal to excess power divided by the product of mass and the gravitational constant.
http://www.hitechcreations.com/forums/showthread.php?s=&threadid=59372&highlight=climb

Acceleration and climb are directly proportional, and depend on the excess thrust.

Again from Hitech:

When we say Climb rate is always perportional to acceleration we meen that if you have an accelerations of 10 mph per sec and a climb rate of 5000 fps, at 160 mph.

Then if acceleration at 200 mph = 5 mph per sec the climb rate at 200 mph must be 2500.

Note you must hold a constant 200 during climb by either raising or lowering the nose.

And they will always be directly perportional.

.............

Acceleration and climb are 100% equivilent functions. And it realy comes down to Acceleration = Gravity, gravity is the oposing force in climbing, mass is the oposing force in acceleration.

http://www.hitechcreations.com/forums/showthread.php?s=&threadid=58498&highlight=climb


Isegrim, you can argue all you like on this, but you are wrong. I know you are wrong because I've read and talked to people who truly understand this, and what they have been telling me for many years is that climb and acceleration are directly proportional, because both are functions of excess power.


Look at actual examples, the Fiat Cr 42s were not known to be particularly fast, but with their biplane design, they easily matched the climb rate of the early Spits/109s even with much weaker engines.

The Fiat Cr 42 had a high climb rate because it was incredibely light, with a fairly powerfull engine (about 840 hp at peak, weight about 1.7 tons). The Spitfire V weighed about 3 times as much, with less than twice the power.

The Fiat no doubt accelerated very well at slow speeds, but it's terrible drag would offset that at high speeds. Without doing a graph, I'd expect the Fiat to win in acceleration only at 150 mph or less.

hop2002
05-10-2005, 03:16 PM
Just remember.. by some guys physics.. wing load is EXTREMELY important in vertical zoom climb


Oldman, that's not what I said at all.

In a vertical climb no lift is required, but to get to that vertical climb you have to pitch up, and wingloading is very important in pitching.

Pitching is pointing the nose up. It's what you do in a horizontal turn, when you pitch the nose "up" in the horizontal. When entering a climb, you pitch the nose up in the vertical.

Any time you are pulling back on the stick, you are pitching up, and you are better off with lower wingloading. (Which is why the Spit and Zero have reputations as good turners. Both have low wingloading)


and Acceleration rules climb performance

Acceleration doesn't "rule" climb performance, they are both aspects of the same thing.

It's easier to grasp if you realise both are simply adding energy to the plane. Acceleration adds kinetic energy, climb adds potential energy. To add energy you need excess thrust.

hop2002
05-10-2005, 03:32 PM
I understand your point and intention. I don't care for the fact that you have created a graph based on pure speculation and labeled it with actual aircraft types. People would easily take this as factual. Maybe a "plane X", "plane Y" label would be better. You certainly make it clear that the graph is conjecture, but, others will certainly try to present it as fact.



Sorry, I meant to reply to this but forgot.

The graph is actually an old one, I had problems uploading new stuff. The graph is one I originally posted on the AH thread I linked to above, http://www.hitechcreations.com/forums/showthread.php?s=&threadid=128024&highlight=climb+AND+lift

The figures were specific to that thread and that argument. I think they're pretty accurate anyway, I believe the 190 figures come from Isegrim (iirc), and Isegrim isn't known for understating German aircraft perforance.

(And Isegrim, note the (iirc) bit, I'm not "accusing" you of supplying the figures, if you say you didn't, fine)

robban75
05-10-2005, 03:34 PM
Looking at the test below the Fw 190 does have a better zoom climb in the game, or so it would seem. I don't know if it's because the Fw 190 is faster, but this is what I got from pulling(gently) up into a 45deg climb from 750km/h. I read the altitude reached for every 50m passed.

Spd - VIII - A-6

750 --- 6 --- 6
700 - 124 - 156
650 - 306 - 360
600 - 507 - 570
550 - 725 - 796
500 - 934 - 1010
450 - 1138 - 1221
400 - 1338 - 1417
350 - 1530 - 1604
300 - 1725 - 1777
250 - 1922 - 1943
200 - 2123 - 2095

OldMan____
05-10-2005, 03:50 PM
But you can CLIMB without anny acceleration. If you throw a paper plane (of the well amde ones) it WILL CLIMB.. without engine. Why? Just LIFT!

So Lift IS quite relevant. You can have a plane that accelerates very well but has too high wing load to keep flying at a certain altitude (an extreme example)



In game you can CLIMB with your nose pointing slighty down (just try t.. a FW190A4 can do it) just try keep level at 700 KPH without pointing nose down.. impossible. All that attempt to climb is from pure lift.


I myself made some quite research, although not DIRECTLY related to planes.. but other fluid dynamics simmulations I work on and this kind of effect does matter a lot! I implemented the code myself and works!


Your Energy approach of problem is perfect and correct. But systems do not convert E perfectly.. so some characteristics of a system rule how efficiently it does this. A plane without wings will be hardly efficient in the task of building up E.
About the lift on zoom.. I told about a sentence (dont know if from you) that says that at very end of zoom while still vertical spit will win cause of wing load. That is ridiculous.. afetr you are tottaly vertical.. it does not matter anymore.

hop2002
05-10-2005, 04:25 PM
But you can CLIMB without anny acceleration. If you throw a paper plane (of the well amde ones) it WILL CLIMB.. without engine. Why? Just LIFT!


No, it's zoom climbing, using up the energy you gave it when you threw it.

I can throw a brick and it will climb until it's energy runs out, and it doesn't have lift.


So Lift IS quite relevant. You can have a plane that accelerates very well but has too high wing load to keep flying at a certain altitude (an extreme example)

That's the point. You need the same lift to fly level, so you need the same lift when accelerating as well as when climbing.

Excess lift won't help the climb any more than it helps the acceleration.


In game you can CLIMB with your nose pointing slighty down (just try t.. a FW190A4 can do it) just try keep level at 700 KPH without pointing nose down.. impossible. All that attempt to climb is from pure lift.

Of course you can, but we're discussing normal climbs, not party tricks.

The way they climbed WW2 fighters was to point the nose up and fly up an incline, and lift in that circumstance is almost exactly equal to weight. The same as in level flight, in other words.

That's why lift and climb are directly proportional, because they are both dependent on excess thrust.


Your Energy approach of problem is perfect and correct. But systems do not convert E perfectly.. so some characteristics of a system rule how efficiently it does this. A plane without wings will be hardly efficient in the task of building up E.

No, but it would be equally bad in climb or level flight.

I'm not arguing lift isn't necessary, of course it is, when I am pointing out is that lift is equally necessary in level flight and climb. In effect a fighter climbs by flying up an incline, and maintains the same angle of attack and lift as it does when flying on the level.

So you can ignore the lift factor in both level flight and climb, because it is almost exactly the same.

To use Isegrim's example, if you take a fighter a increase it's wing area and lift, it doesn't climb better, it's worse because the extra lift has no benefit, whilst the extra drag means less excess power available.


About the lift on zoom.. I told about a sentence (dont know if from you) that says that at very end of zoom while still vertical spit will win cause of wing load.

No, not me. The steeper the climb angle, the less lift you need, at 90 degrees you need zero lift.

MEGILE
05-10-2005, 04:38 PM
Great test Robban, with some interesting results! I had to make a graph in excel so I could visualize it.. not having a logical mind 'n all.
I hope you don't mind http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif http://forums.ubi.com/images/smilies/11.gif

Assuming I keyed in all the right numbers.. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

http://img236.echo.cx/img236/9419/zoom3hr.jpg

p1ngu666
05-10-2005, 05:10 PM
so a vertical climb, its power vs weight and drag?

Blutarski2004
05-10-2005, 05:59 PM
The following guidelines were formulated by Mr John Lee (Asst Director of United Aircraft) in his book "Fighter Facts and Fallacies" (1942):

All other things being equal -

A 10 percent reduction in Wing Loading will REDUCE climb rate at Sea Level by 1 percent.

A 10 percent reduction in Power Loading will INCREASE climb rate at Sea Level by 13 percent.

A 10 percent reduction in Gross Weight will INCREASE climb rate at Sea Level by 14 percent.


Further explanation as follows -

QUOTE -

In the matter ofclimb, the airplane with the small wings and high wing loading will also have the advantage at sea level. The reason is the same, namely, the smaller wings have the smaller drag. On the other hand, it is probable that the angle of climb wil favor the airplane with the low wing loading. It can climb more steeply, although not so fast. It has the advantage in a tight space.

As the airplanes climb to higher altitudes the situation changes. the air is less dense, and both airplanes must fly at a steeper angle of incidence to maintain the same lift upon their wings. Here the large wings are an advantage, for they do not have to fly at as steep an angle as th esmall wings which carry the same load. At this steeper angle the drags of the wings, tail, and body are all increased, and under extreme altitude conditions the airplane with the small wings has much more drag than the airplane with the large wings. Thus, as ceiling is approached, the airplane wit hthe low wing loading has the better climb and the faster high speed as well.

At some intermediate altitude the climb of the two airplanes is equal. The particular altitude is determined by the manner in which the wing area ic changed. If the change i wing area is made by increasing the span of the wing while the chord, or width, is unchanged, considerable advantage in performance is obtained for the arplane with the low wing loading. If the change in area is made by increasing the chord, while the span remains unchanged, relatively small advantage is obtained for the airlane with the low wing loading. The explanation of this phenomena is given later, under the dicussion of "span loading".

- UNQUOTE


What Mr Lee appears to be saying is that Power Loading (now understood as "specific excess power") is the important fundamental indicator of climb rate.
Low Wing Loading only becomes an important factor in climb rate at high altitudes, provided that the wing area is configured to give a low span loading. (Think Ta-152 here)

Hop is correct.

OldMan____
05-10-2005, 07:59 PM
Sorry but no aviation experience will deny newton laws. A force UP (lift is a force up) will help plane go UP. If your lift > your weight you go UP. When you put your nose up you are increasing your lift, by an artificial way.. but you are just changing your lift.

Not even GOD.. not even ME can change that! Lift is a force. so if it is string enough it wil make you climb!

When you r nose is 10 degrees up.. cos(10) * trust is making him move forward.. rest is increasing lift. Also your wing is at higher angle of attack what (until a certain point dependent on wing type increases lift as well).

If you DO not change your nose attitude.. just accelerates.. your plane WILL start going UP!

My father has a PHd in Fluid Dynamics and I would put his expertise in front of almost anything can be trown at these forums. I don‚¬īt speak with him about physics in a while... but I remember well several years ago when he explained me about simple fluids dynamics for my first computer simmulation.

Not saying that power is no major factor. But you CAN have a plane that accelerates worse but wihth better climb! Just need a HUGE wing efficiency difference.


just back to the origin of discussion.

Also above quote would just help FW.. since it says a HIGH WL due to lower drag would help at sea level.. well FW does not have better acceleration because of its wing loading in this game.

Kwiatos
05-11-2005, 02:06 AM
Robban 45deg is not so small angle for zoom climb?

And i wonder how much alt reach both planes at the end of zoom climb with 90 deg angle?

Skalgrim
05-11-2005, 03:25 AM
lift is very important for climb at low altitude too,

compare initialclimb g2 and la-5



la-5 3230kg 1700ps

initialclimb 18m/sec

powerload 0.526


g2 3100kg 1300ps

initialclimb 21m/sec

powerload 0.419

la-5 with 1700ps has 25% better powerloading and therefore to better accelerate as g2 with 1300ps

nevertheless g2 climb better,
because 109 wing make more lift as la-5/7 wing, the g2 need not so good accelerate like la-5 for better initialclimb,

and thefore could the g2 too with weaker accelerate get very good initialclimb.

la-5/7 wing and 109 wing are good example how important lift is for initialclimb, and keep in the mind, initialclimb is low altitude,

that means too at low altitude is lift very important not only at high altitude.



.

Kwiatos
05-11-2005, 04:55 AM
good point Skalgrim

So could be that Spitfire have better climb rate but fw 190 better acceleration acording to british test.

Kurfurst__
05-11-2005, 04:58 AM
Originally posted by hop2002:

Climb is not dependant on lift.
...
Planes climb because they increase their attitude (point the nose up), not because lift is pushing them up.

I thought I throw away my head when I saw this.Wait a minute, DID I see it right, 'Climb is not dependant on lift.' ??!!
I can`t believe my eyes. This is too much of a sillyness, even from Hop with his spitty tunnel vision..

OK, let`s try to apply the Hoppian theory.

Climb is not dependant on lift.
Lift is generated by the wings.
Thus as you don`t need lift, and wings to generate lift, according to the Hoppian physics, a plane without wings will climb exactly as well as a plane with wings...

Riiiiight. For helicopters, which rely on vertical thrust alone to climb up.. but not propellor aircraft.So throw the Hoppian physics developed on-spot to make the Spitty look better (as always) when it completely fails vs. Newton`s physics.

Fixed-wing aircraft on the other hand change their lift factor by pitching upwards, increasing the Angle of Attack on the wings and thus increasing the lift (at the expense of drag). They will produce more lift this way than it`s neccesary to counter their weight which pulls them down. The remaining positive LIFT is pulls the aircraft upwards in steady climbs.

Anybody who says lift is not a factor in climb like Hop does is just out of his mind.

OldMan____
05-11-2005, 05:01 AM
Yeap, but in game FW have NO better climb and NO better Acceleration until 500 kph.

Probably because the drag difference between the planes is not as pronounced as was in RL.

Drag issues are still there in game. Just look as how LA7 accelerates like a rocket than suddenly stops like if hitting a drag wall. These thinga are very hard to mek perfect in a simmulation, but unfortunately are among the most important things.

Kurfurst__
05-11-2005, 05:13 AM
Originally posted by hop2002:
Acceleration and climb are directly proportional, and depend on the excess thrust.

.. and that`s exectly where your misunderstanding originates to.

You think 'excess thrust' is exactly the same value in both climbs and level flights at the same speeds, but it isn`t.

Excess thrust is the total thrust, minus the drag of the airplane at a given angle of attack and airspeed.

And the angle of attack is totally different in level flight and in climb, so is the drag of the airplane : drag is much higher higher in climbs, therefore the excess thrust is much lower than in level flight.

Here`s where higher lift/lower wingloading aircraft has the advantage. The larger wing can generate the same lift at much lower angle of attack than the aircraft with the smaller wing -> less drag in climbs -> higher excess thrust available.

Unlike in the Hoppian physics, where the one and only factor that determines climb rate is excess thrust, which he wrongly believes to be the same value in both climb and level flight, in reality lift and excess thrust are BOTH factors which interact with each other.

And the final note, there`s no single flight test comparison between the FW 190 and the Spit that would attribute better acceleration to the Spit... the fact that Eric Brown noted that the Spit/190`s takeoff run is very similiar, despite the 190`s higher takeoff speed, is very telling.

Kurfurst__
05-11-2005, 05:18 AM
Originally posted by p1ngu666:
so a vertical climb, its power vs weight and drag?

Inertia + plane`s acceleration against drag and gravity, as lift is near zero in vertical zooms.

hop2002
05-11-2005, 07:25 AM
Just a brief reply for now.


Excess thrust is the total thrust, minus the drag of the airplane at a given angle of attack and airspeed.

And the angle of attack is totally different in level flight and in climb, so is the drag of the airplane : drag is much higher higher in climbs, therefore the excess thrust is much lower than in level flight.

No. Angle of attack is the same in level flight and climbs (normal climbs, not nose down 500 mph party tricks)

What changes is attitude, not angle of attack.

Angle of attack is relative to the direction the aircraft is travelling, not to the horizontal, so a plane flying up a 10 degree incline does not have a 10 degree angle of attack.

http://142.26.194.131/aerodynamics1/Lift/Graphics/AOA_Climb.GIF
From the description for the above image:

"Earlier we learned that lift in a climb is slightly less than weight. We also learned that the lift for the typical climb angle of most aircraft is almost equal to weight. For the purpose of this course we will assume that we can set Lift equal to weight in a climb or a descent.

Therefore, the angle of attack required in a climb or descent will be the same as the angle of attack required in level flight.
Sometimes pilots become confused between the concept of Angle of Attack and attitude.

In the diagram above both aircraft are flying at an angle of attack of 7 degrees. In the first case the aircraft is in level flight, therefore the attitude is also approximately 7 degrees.

In the second case the aircraft is climbing at a 10 degree angle. But, the AOA is still 7 degrees. "

http://142.26.194.131/aerodynamics1/Performance/Graphics/Picture1.GIF
http://142.26.194.131/aerodynamics1/Performance/Graphics/Picture2.GIF

Aaron_GT
05-11-2005, 07:57 AM
Therefore, the angle of attack required in a climb or descent will be the same as the angle of attack required in level flight.

That should really carry the additional caveat 'at a particular speed'. The angle of attack tends to change with speed. Hence the angle the Whitley's wing was set at relative to the fuselage, for example - to allow a reasonable attitude for the fuselage when at landing speed, but leading to a nose down attitude when at cruise speed.

hop2002
05-11-2005, 08:12 AM
That should really carry the additional caveat 'at a particular speed'.

Yes. That's what my graph on page 2 of this thread was an attempt to portray, and it's worth pointing it out again, as this thread is getting sidetracked over whether the better climbing plane at a particular speed will indeed accelerate better at that speed.

Blutarski2004
05-11-2005, 09:39 AM
Originally posted by hop2002:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
That should really carry the additional caveat 'at a particular speed'.

Yes. That's what my graph on page 2 of this thread was an attempt to portray, and it's worth pointing it out again, as this thread is getting sidetracked over whether the better climbing plane at a particular speed will indeed accelerate better at that speed. </div></BLOCKQUOTE>



..... Stop trying to confuse everyone with facts.

faustnik
05-11-2005, 09:48 AM
Originally posted by hop2002:
That's what my graph on page 2 of this thread was an attempt to portray, and it's worth pointing it out again, as this thread is getting sidetracked over whether the better climbing plane at a particular speed will indeed accelerate better at that speed.


That's OK Hop. This has turned into an educational thread.

Kurfurst__
05-11-2005, 10:02 AM
Originally posted by Blutarski2004:
..... Stop trying to confuse everyone with facts.

Well at least nobody can accuse you with that, so it`s coming from the right person, who never tried to confuse anyone with facts. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Blutarski2004
05-11-2005, 12:04 PM
Originally posted by Kurfurst__:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Blutarski2004:
..... Stop trying to confuse everyone with facts.

Well at least nobody can accuse you with that, so it`s coming from the right person, who never tried to confuse anyone with facts. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif </div></BLOCKQUOTE>


..... I'm not sure whether that was intended as an insult. I'll assume that it was not and rack it up to your special sense of humor.

In the interests of expanding on the topic at hand, consider this fact. Suppose that an aircraft flying at X speed produces 1G of lift (i.e. - enough lift to maintain level flight). If that same aircraft increases its speed to 2X, lift increases by a factor of 4 without changing the angle of attack of the a/c. In other words, lift varies as the square of the speed.

The drag created at 2X speed is considerably greater than that at X speed; this is what consumes the excess available thrust or power. At 2X speed, the pilot may opt to reduce the angle of attack to the point where 1G lift is being generated. Reduced angle of attack means reduced drag and the excess thrust again becomes available to accelerate to a higher speed. That's one of the reasons why trim must be changed as speed changes.

There are all sorts of airfoils with differing lift/drag relationships and different suitabilities for particular speed regimes. But, in terms of lift/drag for airfoil shapes used in WW2 fighters, the differences are incremental at best. In basic terms lift is paid for in drag. You can have the finest lift-producing airfoil ever conceived by man. Without sufficient power to propel it through the air, the climb rate will be low.

Of course, you knew that already. It's elementary aerodynamics.

Climb rate is dependent upon the availability of excess thrust or power. Lift increases as the square of the speed. Drag increases as the square of the speed. Therefore, climb rate is more or less directly related to the availability of excess power.

Acceleration is also directly related to the availability of excess power. The charts of WW2 fighter acceleration rates versus available excess power which I have seen show a direct relationship.

You can debate the fine points of this or that, but Hop is fundamentally correct.

OldMan____
05-11-2005, 12:19 PM
Yeap fundamentally correct.. but IS POSSIBLE at special situations to have planes with smaller acc but higher climb. Not common but possible if wing efficiency is drastically different. Also some wings are well suited only at specific speeds.

robban75
05-11-2005, 01:02 PM
Originally posted by Megile:
Great test Robban, with some interesting results! I had to make a graph in excel so I could visualize it.. not having a logical mind 'n all.
I hope you don't mind http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif http://forums.ubi.com/images/smilies/11.gif


I don't mind at all! Thanks for making the graph, it gets so much easier to see the actuall difference! http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

robban75
05-11-2005, 01:04 PM
Originally posted by quiet_man:
@robban75
still in testing mod?

try the ones below I did with earlier IL2 version, they show an FM limitation with disadvantage for 190
I think the missing inertia effect Oleg wants to include in 4.0 FM


What version of IL2 is that from? With the dive speed being equal for the planes listed it must be quite old. Differential dive acceleration has been modelled for some time now. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

quiet_man
05-11-2005, 01:42 PM
Originally posted by robban75:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by quiet_man:
@robban75
still in testing mod?

try the ones below I did with earlier IL2 version, they show an FM limitation with disadvantage for 190
I think the missing inertia effect Oleg wants to include in 4.0 FM


What version of IL2 is that from? With the dive speed being equal for the planes listed it must be quite old. Differential dive acceleration has been modelled for some time now. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif </div></BLOCKQUOTE>

can't remember what version
you have to watch that the dive test was for low speed, there all plane should indeed dive the same as all are accelerated by ~1g

but the real point is about speed lose by drag being wrong, the heavy 190 should lose speed slower then say a Yak. So when you dive and pull out level the 190 should gain an speed advantage as the Yak loses speed faster

but at this version of IL2 the 190 had the low accel from weight but it did not get the inertia, all planes loses speed the same

if this is still so, all heavy planes are troubled and I wonder if this is the inertia effect Oleg spoke about to be added in 4.0

quiet_man

Blutarski2004
05-11-2005, 01:48 PM
Originally posted by OldMan____:
Yeap fundamentally correct.. but IS POSSIBLE at special situations to have planes with smaller acc but higher climb. Not common but possible if wing efficiency is drastically different. Also some wings are well suited only at specific speeds.


..... I agree such a thing is certainly possible. An aerodynamically very "dirty" aircraft could possibly have a terrific climb rate at 200 mph, but face very big drag issues when accelerating to high speed.

It would be interesting to make a graph of WW2 fighters comparing initial climb rates versus installed engine power, and another graph comparing maximum speed with maximum climb rate.

Aaron_GT
05-11-2005, 03:52 PM
Yes. That's what my graph on page 2 of this thread was an attempt to portray, and it's worth pointing it out again

Ah, that was o long ago it's like remembering a previous life :-)

p1ngu666
05-11-2005, 05:14 PM
id say 190 can slow down really quick in combat, its happened several times to me, i fly past a 190 because hes lost a ton of speed real fast http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

Skalgrim
05-11-2005, 09:09 PM
think is not right that plane with high weigh had good zoomclimb, at least it seem when you compare 190a5 and f4u-1d


a5 with 1.42 ata 1750ps and f4u-1d 2300ps have same zoomclimb from american test, but f4u-1d has much more weigh and power, and nevertheless a5 has same zoomclimb

accelerate and drag seem very important for zoomclimb,


when a5 with 1750ps has same zoomclimb like f4u-1d with 2300ps,

should a9 with 2300ps power easy outzoom f4u-1d,
although the f4u-1d has much more weigh.

when i right remember 109f could stay zoomclimb with 190a3,

a3 with much more weigh has not better zoomclimb as f4,



plane with doubles weigh has the doubles kenetic energie by same speed, but it need too doubles kenetic energie to get same altitude with same drag.

so is it on par,

weigh help for deep, because weigh works same direction, but that is not case by zoomclimb.



.

Skalgrim
05-12-2005, 04:36 AM
yes,

but not forgotten then the g2 1300ps and la-5 1700ps to show in the graph,

although the la-5 has 25% higher powerload as g2 get the g2 almost 17% better initialclimb




Originally posted by Blutarski2004:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by OldMan____:
Yeap fundamentally correct.. but IS POSSIBLE at special situations to have planes with smaller acc but higher climb. Not common but possible if wing efficiency is drastically different. Also some wings are well suited only at specific speeds.


..... I agree such a thing is certainly possible. An aerodynamically very "dirty" aircraft could possibly have a terrific climb rate at 200 mph, but face very big drag issues when accelerating to high speed.

It would be interesting to make a graph of WW2 fighters comparing initial climb rates versus installed engine power, and another graph comparing maximum speed with maximum climb rate. </div></BLOCKQUOTE>

quiet_man
05-12-2005, 09:16 AM
Originally posted by Skalgrim:
...
plane with doubles weigh has the doubles kenetic energie by same speed, but it need too doubles kenetic energie to get same altitude with same drag.

so is it on par,
...
.

yes, 1g is acceleration not force, so all planes should have similar dive and zoom climb

the only difference is drag and inertia and this effects are the same in level flight (at high speed were wingload is not important)

that's why I tested deacceleration in levelflight, it shows how the plan will dive and zoom climb. As you can see, the values were similar for all planes, translating in similar dive and zoom climb like we had them in the past FM


I think in reality most pilots pulled out with less "g" than we do in the game were you cannot feel/suffer from it, so they spend more time near level flight making the difference between light and heavy planes even larger

quiet_man

quiet_man
05-12-2005, 09:23 AM
Originally posted by p1ngu666:
id say 190 can slow down really quick in combat, its happened several times to me, i fly past a 190 because hes lost a ton of speed real fast http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

if inertia is not in current FM that might be one of the reasons

quiet_man

hop2002
05-12-2005, 10:26 AM
Isegrim posted a thread on the AH board questioning whether climb and accelerated are proportional, as I claimed.

http://www.hitechcreations.com/forums/showthread.php?s=&threadid=150423

Amongst the replies are these:


Lift does not effect climb rate, only power. Basicly in any normal climb the lift generated = the weight of the air plane (btw is only close the amout of lift goes down the steaper you climb).

Adding more lift makes the plane loop.

It is the power that is pulling you up the hill. Think of lift like the tires of your car. They holds the car up just like lift does. But it is the engine that pulles it up the hill.

Hitech (Hitech is the creator of AH)



I'm with Nashwan on the validity of the conclusion climb rate->acceleration at a fixed speed, provided the simulation physics are consistent :-)

(If the individual aircraft models are inaccurate as suggested by Kurf√ľrst, that wouldn't affect the conclusion as long as we consider only the game, not historic reality.)

Nashwan's comment on the relative speeds seem reasonable - if you're interested, I could try and graph relative acceleration for a set of assumptions about both planes' performance.

I think I can solve the excess power issue: It's not total excess thrust that counts, it's specific excess thrust. In other words, it's excess thrust divided by aircraft mass - I'm sure the Spitfire variant in question is some 500 kg lighter than the Fw 190, so it gets comparable low-speed performance out of lower total thrust.

(As Hitech pointed out, lift is not an issue in a climb. Weight certainly is, thus the use of specific excess thrust.)

HoHun


I would like to point out that Hitech has already posted a perfectly correct response‚‚ā¨¬¶ Aircraft climb with their engines not their wings! Climb angle depends on specific excess thrust and climb rate on specific excess power. The lift only influences the speed at which it all happens. Hitech‚‚ā¨ôs car climbing a hill analogy is good.

Badboy


Both accel and climb are purely about PsubS, excess power. The only influence lift has on either is the induced drag, and the change in induced drag as the aircraft accelerates.

The equations are even similar:

Accel(fps) = xThrust(lbs) / Slugs (weight(lbs)/32.2)

Climb(fpm) = 33000/weight(lbs) * xHP

(By definition 1 HP lifts one lb 33,000 ft in one minute. That is where the 33,000 comes from)

Note that one equation is in xHp and the other in xThrust, so you will have to convert between units to solve them. But the end result is that climb and accel are both purely PsubS. Whoever has the best climb rate at any fixed speed will have the best accel at the same fixed speed, and vice versa.
GWShaw

I think even Isegrim accepts now that climb and acceleration at any speed and altitude are directly proportional, and that the plane with the better climb rate will also have better acceleration (at any particular speed/altitude)

Blutarski2004
05-12-2005, 10:48 AM
Originally posted by hop2002:
I think even Isegrim accepts now that climb and acceleration at any speed and altitude are directly proportional, and that the plane with the better climb rate will also have better acceleration (at any particular speed/altitude)


..... His sudden silence on this thread may indicate so. Frankly, I'm surprised that he was not aware of this in the first place.

robban75
05-12-2005, 10:49 AM
What was the hp output for the Merlin 66 at 18 lbs and 25 lbs boost?

hop2002
05-12-2005, 11:48 AM
Rammed about 1580 hp at sea level at 18 lbs, about 1980 hp at sea level at 25 lbs. Static would be a bit higher.

Peak was about 1680 hp at around 9,000 ft at 18lbs, about 2040 hp at around 4,000ft at 25 lbs.

OldMan____
05-12-2005, 11:57 AM
Originally posted by hop2002:
Isegrim posted a thread on the AH board questioning whether climb and accelerated are proportional, as I claimed.

http://www.hitechcreations.com/forums/showthread.php?s=&threadid=150423

Amongst the replies are these:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Lift does not effect climb rate, only power. Basicly in any normal climb the lift generated = the weight of the air plane (btw is only close the amout of lift goes down the steaper you climb).

Adding more lift makes the plane loop.

It is the power that is pulling you up the hill. Think of lift like the tires of your car. They holds the car up just like lift does. But it is the engine that pulles it up the hill.

Hitech (Hitech is the creator of AH)



I'm with Nashwan on the validity of the conclusion climb rate->acceleration at a fixed speed, provided the simulation physics are consistent :-)

(If the individual aircraft models are inaccurate as suggested by Kurf√ľrst, that wouldn't affect the conclusion as long as we consider only the game, not historic reality.)

Nashwan's comment on the relative speeds seem reasonable - if you're interested, I could try and graph relative acceleration for a set of assumptions about both planes' performance.

I think I can solve the excess power issue: It's not total excess thrust that counts, it's specific excess thrust. In other words, it's excess thrust divided by aircraft mass - I'm sure the Spitfire variant in question is some 500 kg lighter than the Fw 190, so it gets comparable low-speed performance out of lower total thrust.

(As Hitech pointed out, lift is not an issue in a climb. Weight certainly is, thus the use of specific excess thrust.)

HoHun


I would like to point out that Hitech has already posted a perfectly correct response‚‚ā¨¬¶ Aircraft climb with their engines not their wings! Climb angle depends on specific excess thrust and climb rate on specific excess power. The lift only influences the speed at which it all happens. Hitech‚‚ā¨ôs car climbing a hill analogy is good.

Badboy


Both accel and climb are purely about PsubS, excess power. The only influence lift has on either is the induced drag, and the change in induced drag as the aircraft accelerates.

The equations are even similar:

Accel(fps) = xThrust(lbs) / Slugs (weight(lbs)/32.2)

Climb(fpm) = 33000/weight(lbs) * xHP

(By definition 1 HP lifts one lb 33,000 ft in one minute. That is where the 33,000 comes from)

Note that one equation is in xHp and the other in xThrust, so you will have to convert between units to solve them. But the end result is that climb and accel are both purely PsubS. Whoever has the best climb rate at any fixed speed will have the best accel at the same fixed speed, and vice versa.
GWShaw

I think even Isegrim accepts now that climb and acceleration at any speed and altitude are directly proportional, and that the plane with the better climb rate will also have better acceleration (at any particular speed/altitude) </div></BLOCKQUOTE>

wait a second. Yourself said earlier.. not ANY altitude.. but any altitude up tp the point where air density drop to levels where extra lift efficiency is required in wings.

3.JG51_Stecher
05-12-2005, 12:07 PM
Originally posted by robban75:
What was the hp output for the Merlin 66 at 18 lbs and 25 lbs boost?

I haven't read this whole thread, so sorry if you're looking for specific altitudes, but I found this googling.

----------

"Merlin 66, 1,315 hp. A two-speed, two-stage supercharged low-altitude engine, similar to Mk 63 and 65 but with interconnected engine controls and a Stromberg injection carburettor. The Merlin 55 was the most effective engine in teh Spitfire in regular operation and it flew consistently at +25 lb boost at over 2,000 hp, both on anti-flying bomb operations and against the Luftwaffe. RM.10SM Rating. Propeller reduction gear .477:1. RM10.SM. 2,992 built at Derby, 2,558 at Crewe, 816 at Glasgow, 1943 - 1945.
Aircraft: Supermarine Spitfire F.VIII, LF.IX, T.8, T.9"

Elsewhere
R-R Merlin 66 V-1650-7
Fuel Spec. J. 100 oct, 100/130 grade
take-off. 1,330hp, 3,000rpm, +12 boost
normal continuous power. 1,410hp, 2,850rpm, +12 boost, 8,500ft (at medium supercarged)
1,310hp, 2,850rpm, +12 boost, 18,000ft (at fully supercharged)
maximum power. 1,750hp, 3,000 rpm, +18 boost, 5,250ft (medium supercharged)
1,625hp, 3,000rpm, +18 boost, 12,500ft (fully supercharged).

For L. 100 oct, 100/150 grade fuel maximum power figures are
2,000hp, 3,000rpm, +25 boost, 5,250ft (medium supercharged)
1,860hp, 3,000rpm, +25 boost, 11,000ft (fully supercharged)

Elsewhere - "Fuel Specifications Key"
"J 100/130 grade, 100 Octane (lower figure for weak mixture, upper figure rich) +5.5cc TEL/Imperial Gallon, DED 2475"
"L 100/150 grade, 100 Octane ... +7.2 TEL/Imperial Gallon. This was a special fuel, containing mono-methyl-aniline, developed at the end of the Second World War, permitting very high boost and giving a lot more power, without detonation, for chasing flying bombs. The S.U. type carburettor was cleared potentially for a + 21 lb boost on 150 grade fuel which became available in 1944. It enable +25 lb boost on certain types of engine and would have been cleared for +30 lb, had the war not finished."

from BRITISH PISTON AERO-ENGINES AND THEIR AIRCRAFT (Lumsden) (copy is available at the library at Deniz's alma mater).

----------

Got it from here: http://www.us-aircraft.com/bbs/navy_config.pl?read=1407

Blutarski2004
05-12-2005, 12:21 PM
Originally posted by OldMan____:

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Hop wrote -
I think even Isegrim accepts now that climb and acceleration at any speed and altitude are directly proportional, and that the plane with the better climb rate will also have better acceleration (at any particular speed/altitude)

wait a second. Yourself said earlier.. not ANY altitude.. but any altitude up tp the point where air density drop to levels where extra lift efficiency is required in wings. </div></BLOCKQUOTE>


..... There is no contradiction in Hop's statement. At 9,000 meters it could well be the a/c which has a lower wing loading (and lower span loading) which has the better climb rate. But that will be true because at that high altitude it suffers less drag and will therefore have more excess thrust available. If that a/c has the greater climb rate, it will also have the better acceleration.

See Blutarski's first post on this thread for a basic explanation of the relationship between wing loading, span loading, and altitude.

robban75
05-12-2005, 01:19 PM
Thanks Hop, and thanks Stecher for the information. http://forums.ubi.com/images/smilies/16x16_smiley-happy.gif

WWMaxGunz
05-12-2005, 05:41 PM
Just remember that engine is not thrust. Thrust varies with speed, alt and the prop.
Oleg already invalidated one set of tests not matching someones data by pointing out
that the 190 that made the data had a different prop from the one in FB.

It's possible to have two of the same model plane with different props and one will
accelerate faster at lower speed while the other will be the faster plane. Almost
like having different gearing on otherwise identical road vehicles.

Without good data, you might as well try betting on horse races or boxing matches.
And then complaining to the managers if the ~wrong~ one wins!

Kurfurst__
05-13-2005, 11:46 AM
Originally posted by hop2002:
Isegrim posted a thread on the AH board questioning whether climb and accelerated are proportional, as I claimed.

Amongst the replies are these:

They pretty convincingly proved you wrong, even if Hop has doctored the qoutes and cut off the parts which directly contradict his theory that was 'Climb is not dependant on lift' and that the Spitfire had acceleration adv over the 190.


Lift does not effect climb rate, only power. Basicly in any normal climb the lift generated = the weight of the air plane (btw is only close the amout of lift goes down the steaper you climb).

Read : If you have more lift generated during climb (as the Spitfire does), you will have more excess power. It leads you to higher climb rate. Exactly what I said, the Spitfire`s is in advantage only in climbs at VERY low speeds. At all practical speeds the FW 190 outaccelerates the Spitfire.



I would like to point out that Hitech has already posted a perfectly correct response‚‚ā¨¬¶ Aircraft climb with their engines not their wings! Climb angle depends on specific excess thrust and climb rate on specific excess power. The lift only influences the speed at which it all happens. Hitech‚‚ā¨ôs car climbing a hill analogy is good.

Badboy


Again, this proves Hop wrong.

'The lift only influences the speed at which it all happens.'

What does that mean? With more lift, you can climb at lower airspeeds. The Spit had more lift, and as per it`s manuals, it climbed best at lower airspeeds than the FW. Ie. a Spit would climb at 4000 fpm at 170 mph, a FW 190 would climb at 4000 fpm at 190mph.

Obviously, at lower airspeeds there is less drag, and more excess thrust is available for climb... hence the higher excess thrust leading to higher climb rate. The Spitfire has higher climb rate because it has more lift available, and has more excess thrust due to lower drag at lower climb speeds. But the excess thrust from peak climb rate of the Spit/190 are not comparable, as they DO NOT climb at the same speed.




Both accel and climb are purely about PsubS, excess power. The only influence lift has on either is the induced drag, and the change in induced drag as the aircraft accelerates.

The equations are even similar:

Accel(fps) = xThrust(lbs) / Slugs (weight(lbs)/32.2)

Climb(fpm) = 33000/weight(lbs) * xHP

(By definition 1 HP lifts one lb 33,000 ft in one minute. That is where the 33,000 comes from)

Note that one equation is in xHp and the other in xThrust, so you will have to convert between units to solve them. But the end result is that climb and accel are both purely PsubS. Whoever has the best climb rate at any fixed speed will have the best accel at the same fixed speed, and vice versa.
GWShaw


GWShaw`s comments that follow that line - the ones that Hop cut out because they disprove him - are even more interesting :

"..Note that one equation is in xHp and the other in xThrust, so you will have to convert between units to solve them. But the end result is that climb and accel are both purely PsubS. Whoever has the best climb rate at any fixed speed will have the best accel at the same fixed speed, and vice versa.

[i]But as HoHun has pointed out the situation is dynamic, not static. As the aircraft accelerates the induced drag decreases, pressure drag increases and P% changes. All of those factors are to the Fw 190A's advantage in a drag race from say 150 mph IAS vs a Spitfire V. The Spitfire's drag curves will cross about 160 mph, the Fw's about 180 mph or so. So while the Spitfire's total drag will start to increase about 160 mph, the Fw's will continue decreasing to about 180 mph. The Fw will retain the advantage of lower total drag all the way to vMax.


It`s understandable why Hop has cut this off. Unlike in the game, the FW 190 should have acceleration advantage over the Spitfire at all but near-stall airspeeds.... GWshaw basically said the FW190 outaccelerates the Spitfire above 180mph all the way to 350mph.

Exactly the contrary what hop is claiming.



I think even Isegrim accepts now that climb and acceleration at any speed and altitude are directly proportional, and that the plane with the better climb rate will also have better acceleration (at any particular speed/altitude)


Sigh, Hop, they are not, there are far too many variables to cope with with two different plane designs, Oldboy had mentioned a few of those for you. You choose to ignore the factors that effect it,you choose to ignore it`s a dynamic process, you present us doctored incomplete qoutes, you cut off the parts that prove you wrong.

You build misinformation from a pile of half-truths.

Other comments from the same thread Hop was selectively picking from :

Mando : "Well, I would say that the less the lift, the more the needed power from engine to keep the same climb rate. "

Angus : "But if you have a surface that creates lift, given an A.o.A., then the power needed to create the lift is less. "

BUG_EAF322 : "lift is a factor"


Perhaps Blutarski and Hop get on so well because they share the a custom of selectively/misqouting people...

faustnik
05-13-2005, 12:52 PM
Here is the equation that I use for interpreting posts here:


Hop2002 > Truth < Kurfurst



It always works. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

ICDP
05-13-2005, 12:58 PM
Originally posted by faustnik:
Here is the equation that I use for interpreting posts here:


Hop2002 > Truth < Kurfurst



It always works. http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

LOL

I tend to ignore them both, they obviously have a lot of knowledge on the subject of WWII fighters. The problem is they are both so blinkered and stubborn that anything they post is viewed by me in the same way as the rantings of an extremist http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

No offence Hop and Kurfurst but lighten up a bit http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

faustnik
05-13-2005, 01:14 PM
Originally posted by ICDP:
I tend to ignore them both, they obviously have a lot of knowledge on the subject of WWII fighters.


I give them both a hard time occasionally, but, that doesn‚‚ā¨ôt mean that I don‚‚ā¨ôt appreciate their posts. Their posts often contain interesting data that forces you to think about the question at hand.

http://pages.sbcglobal.net/mdegnan/_images/Dr.jpg

p1ngu666
05-13-2005, 01:53 PM
their talkin about vb vs 190, we are talkin about ix vs 190?

hop2002
05-13-2005, 03:01 PM
their talkin about vb vs 190, we are talkin about ix vs 190?

Yes, Isegrim sought to "broaden" the argument.


They pretty convincingly proved you wrong, even if Hop has doctored the qoutes and cut off the parts which directly contradict his theory that was 'Climb is not dependant on lift' and that the Spitfire had acceleration adv over the 190.

Isegrim, the thread is there for all to see.


Lift does not effect climb rate, only power. Basicly in any normal climb the lift generated = the weight of the air plane (btw is only close the amout of lift goes down the steaper you climb).



Read : If you have more lift generated during climb (as the Spitfire does), you will have more excess power.

The same is true during acceleration. In level flight the lift generated = weight of the plane.

That's why your reasons for disbelieving that lift and climb are proportional are wrong. The wing generates the same amount of lift whether climbing or flying in level flight, (at a particular speed/altitude), so wing design has the same effect on level flight and acceleration.


I would like to point out that Hitech has already posted a perfectly correct response‚‚ā¨¬¶ Aircraft climb with their engines not their wings! Climb angle depends on specific excess thrust and climb rate on specific excess power. The lift only influences the speed at which it all happens. Hitech‚‚ā¨ôs car climbing a hill analogy is good.

Badboy



Again, this proves Hop wrong.

'The lift only influences the speed at which it all happens.'

What does that mean? With more lift, you can climb at lower airspeeds. The Spit had more lift, and as per it`s manuals, it climbed best at lower airspeeds than the FW. Ie. a Spit would climb at 4000 fpm at 170 mph, a FW 190 would climb at 4000 fpm at 190mph.

Actually not true for the 190 and Spit LF IX, the Spit seems to have had a slightly higher speed for best climb.

But the point is moot anyway, because I pointed out in the very first post that's it's all speed dependent.

If you look at the graph I posted, it shows climb rate (and acceleration) decreasing with speed, and decreasing faster for the slower plane.


Obviously, at lower airspeeds there is less drag, and more excess thrust is available for climb... hence the higher excess thrust leading to higher climb rate.

Which is why I said it was speed dependant.

Which is why my graph shows the initial climb/acceleration advantage of the Spitfire being overtaken by the 190.

You are the only person who seems to have failed to grasp that.


The Spitfire has higher climb rate because it has more lift available, and has more excess thrust due to lower drag at lower climb speeds. But the excess thrust from peak climb rate of the Spit/190 are not comparable, as they DO NOT climb at the same speed.

Actually they climb at very similar speeds, but the method works even if the speeds are very disimilar.

Here's an example of 2 planes with very disimilar climb speeds/rates/top speeds:

http://www.onpoi.net/ah/pics/users/282_1116016650_hypothetical.gif

The Blue plane has a climb rate of 4800 ft/min at 105 mph, the red plane 2000ft/min at 175 mph.

As you can see, very disimilar, but the method of graphing them still allows valid conclusions to be drawn at other speeds.

It's safe to say the blue plane has a climb/acceleration advantage up to about 240 mph (as I've said all along, this method is only approximate, because drop in climb/acceleration is not linear with speed)


[I]But as HoHun has pointed out the situation is dynamic, not static. As the aircraft accelerates the induced drag decreases, pressure drag increases and P% changes. All of those factors are to the Fw 190A's advantage in a drag race from say 150 mph IAS vs a Spitfire V. The Spitfire's drag curves will cross about 160 mph, the Fw's about 180 mph or so. So while the Spitfire's total drag will start to increase about 160 mph, the Fw's will continue decreasing to about 180 mph. The Fw will retain the advantage of lower total drag all the way to vMax.


It`s understandable why Hop has cut this off.

Yes, it is.

It's talking about the Spit V, which is not what this thread was about.

Note that GWShaw still supported my claim, as did the others in the thread.

In fact, you don't seem to have found a quote that shows I'm wrong, just a lot of quotes about ancillary aspects.

Note what else gwshaw said:


There is really no contradiction between a Spitfire V being able to outclimb a Fw 190A at climb speeds, and the Fw 190A being able to out accelerate the Spitfire V over time. The Spitfire V would have an initial advantage, but that would swing further and further in the Fw 190's favor as speed increased.

See Isegrim, everybody agreed that climb is dependant on power, not increased lift, and that the plane with a climb rate advantage at a particular speed will also have an acceleration advantage at that speed.


Unlike in the game, the FW 190 should have acceleration advantage over the Spitfire at all but near-stall airspeeds.... GWshaw basically said the FW190 outaccelerates the Spitfire above 180mph all the way to 350mph.

gwshaw is talking about the Spitfire V, this thread is about the Spitfire LF IX. I think we can agree the Spitfire LF IX should have an acceleration advantage over the V, or do you want a long tedious argument about that as well?


Exactly the contrary what hop is claiming.

No Isegrim, exactly what I am claiming.

Do you even understand what I did claim in the first place?


Sigh, Hop, they are not, there are far too many variables to cope with with two different plane designs, Oldboy had mentioned a few of those for you.

They are, as agreed by the engineers on that thread.

Design variables hardly matter when test results are available.

Note the following statement:

We cannot say the 109K4 is faster than the Spitfire V because there are two many design variables (power, wing loading, drag etc) to take into account.

It's silly, isn't it?

You need the design parameters to calculate expected performance, you don't need them to draw conclusions from tested performance.


You choose to ignore the factors that effect it,you choose to ignore it`s a dynamic process, you present us doctored incomplete qoutes, you cut off the parts that prove you wrong.

Isegrim, none of those parts proved me wrong. Some don't prove me right, because they are talking about other things, but the stuff directly on topic confirmed what I said in the first place.

Quite honestly your grasp on physics seems to weak to understand what you are arguing about.


Mando : "Well, I would say that the less the lift, the more the needed power from engine to keep the same climb rate. "

And the less the lift, the more power is needed to keep level flight.

Note I am not arguing wing design has no effect on performance, just that it has the same effect whether climbing or in level flight.

As I said, acceleration and climb are directly related. To quote Hitech:

Lift does not effect climb rate, only power. Basicly in any normal climb the lift generated = the weight of the air plane

or HoHun:

The thing to remember is that acceleration and climb rate are proportional only as long as you keep the comparison speed constant. That means if you compare published climb figures, they only tell you about acceleration at that speed.

(This is exactly what I argued from the begining, and why my graph shows climb rate/acceleration with speed)

or HoHun again:

I'm with Nashwan on the validity of the conclusion climb rate->acceleration at a fixed speed, provided the simulation physics are consistent
(I'm Nashwan on the AH boards btw)

or Badboy

I would like to point out that Hitech has already posted a perfectly correct response‚‚ā¨¬¶ Aircraft climb with their engines not their wings! Climb angle depends on specific excess thrust and climb rate on specific excess power. The lift only influences the speed at which it all happens.

or gwshaw

Both accel and climb are purely about PsubS, excess power. The only influence lift has on either is the induced drag, and the change in induced drag as the aircraft accelerates.


Angus : "But if you have a surface that creates lift, given an A.o.A., then the power needed to create the lift is less. "

Of course it does. But AoA is almost identical in level flight and normal climbs, so it's not going to make a difference between acceleration and climb rate.

Isegrim, do you want to take this back to the AH thread? I'm sure someone there can give you a clearer explanation that you will be able to understand.

hop2002
05-13-2005, 03:15 PM
Here is the equation that I use for interpreting posts here:


Hop2002 > Truth < Kurfurst



It always works.

That's probably a pretty valid method for opinion psots, as Isegrim and I tend to take diametrically opposed positions.

This is about physics though, and physics is one of those subjects with right and wrong answers, so taking a halfway position isn't going to work.

Unlike most threads where there is some validity in Isegrim's position, in this one he is simply wrong

Climb rate and acceleration are directly linked at any particular speed, because they are both functions of excess thrust, and physics doesn't allow any fudging.

(Isegrim's argument actually works if you believe AoA is higher duing the climb than in level flight, at the same speed/altitude. However, AoA is the same, therefore so is drag, therefore so is excess power, therefore so is climb/acceleration) (within reason, of course)


No offence Hop and Kurfurst but lighten up a bit

I'm actually pretty relaxed about this, because I don't have to go and look up facts and figures and research. This is a pretty simple point, and it's something I am pretty confident about.


Their posts often contain interesting data that forces you to think about the question at hand.


I agree with you, Isegrim often posts interesting and informative stuff, and I've learned a lot in both from it, and from researching my replies to it. (And the same with many other posters, I really started to get in to WW2 aircraft in response to debates I had with Slickun on the old Combatsim forums)

Aaron_GT
05-13-2005, 04:18 PM
And the less the lift, the more power is needed to keep level flight.

The less lift the higher the stall speed thus the more power needed to keep the plane above the stall speed, but at higher speeds less power is needed to keep level flight in the plane with a less lift as induced drag is also less (assuming the lift is greater than weight of course!). That's why the likes of the P51 had low lift wings - to reduce insuxws drag at high speeds. At climb speeds, which are above stall speeds, the induced drag is a less dominant term.

WWMaxGunz
05-13-2005, 06:48 PM
From vector analysis at the aero site I've linked to here before, the lift on a climbing
plane is actually less than the weight of the plane, the power leg does more than raise
the rig. Neat, huh? If the plane moves fast enough to get more lift, the nose comes up
and you either have to nose down or climb.

Hop < Truth > Isegrim ..... truth is where it would be alone, the others stand relative.