Dora roll rate and turning rate, true to real-life data?

It has long been known that those figures are incorrect, esp. seeing as that would mean that the Fw190's were stalling before landing :lol:

 

The reason for this is that the 190A Eric brown flew suffered from a host of issues, incl. mis adjusted ailerons leading to aileron reversal and premature stalls.

No, that was meant to demonstrate how much the 190's stall speed gets lower with flaps.

So yeah if A2A based their figures on that one report by Brown then that explains it :megalol:

Who said they did?

 

 

I didn't say so.

 

 

Again what's with the landing distance?? The landing speed is what we're talking about here, not the landing distance.

But you seems to think it's related alot, no. Landing speed is not absolute, it's a decided number, it can be quite bit higher or barely higher than the stall speed. Stall speed on the other hand is indisputable. And I'm pretty sure earlier you were dragging landing distance into this.

 

 

A low stall speed is worth nothing by itself.

You also seem to ignore the effect of lower drag in turning prowess. And as I told you, not a single Mustang outside of wind tunnel test achieved laminar effect(and the wind tunnel test was a model, not a real plane)
Edited April 7, 2015 by GrapeJam

Also British test of captured FW 190A3:

http://www.a2asimulations.com/store/fw190/tactical_trials.htm

The stalling speed of the aircraft is high, being approximately 110 m.p.h. (177 k.m./h.) with the undercarriage and flaps retracted, and 105 m.p.h. [169 k.m./h.| with the undercarriage and flaps fully down. All controls are effective up to the stall. One excellent feature of this aircraft is that it is seldom necessary to retrim under all conditions of flight.

 

And this FW 190A3's weight was 8600lbs.

No, that was meant to demonstrate how much the 190's stall speed gets lower with flaps.

 

Only it didn't prove anything considering all the problems said aircraft was suffering from, incl. one that caused premature stalls.

 

Who said they did?

 

You certainly implied they did.

 

But you seems to think it's related alot, no. Landing speed is not absolute, it's a decided number, it can be quite bit higher or barely higher than the stall speed. Stall speed on the other hand is indisputable. And I'm pretty sure earlier you were dragging landing distance into this.

 

Never have and never will, go back and read through the thread.

 

As for landing speed, it is rather absolute infact, to within a few mph, if the aircraft are designed to land on a paved landing strip.

 

You also seem to ignore the effect of lower drag in turning prowess. And as I told you, not a single Mustang outside of wind tunnel test achieved laminar effect(and the wind tunnel test was a model, not a real plane)

 

I mentioned that a lot earlier. True laminar flow was not achieved due to the desired smoothness of the wing surface not being attainable in the field, or even out the factory. As such the reduction in drag wasn't as great as thought, but it was still lower than with a regular airfoil by virtue of shape alone. The same issues with a sharp stall and low clmax were still apparent however due again to the shape, laminar flow or not didn't change that.

As for landing speed, it is rather absolute infact, to within a few mph, if the aircraft are designed to land on a paved landing strip.

Seeing as the FW 190 was also designed to operate in Russia's harsh air strip don't you think the landing speed in the manual would be on the low side?

I mentioned that a lot earlier. True laminar flow was not achieved due to the desired smoothness of the wing surface not being attainable in the field, or even out the factory. As such the reduction in drag wasn't as great as thought, but it was still lower than with a regular airfoil by virtue of shape alone. The same issues with a sharp stall and low clmax were still apparent however due again to the shape, laminar flow or not didn't change that.

And the P63 did achieve laminar flow effect(mostly), does that tell you something? That the Mustang's wings design don't lose as much lift as you think because it's not laminar enough?
Edited April 7, 2015 by GrapeJam

Also British test of captured FW 190A3:

http://www.a2asimulations.com/store/fw190/tactical_trials.htm

 

 

And this FW 190A3's weight was 8600lbs.

 

See the discrepency?

 

Here we have a significantly lower clean stall speed (110 vs 127 mph), but a higher dirty stall speed (105 vs 102 mph).

 

Hence these figures are not to be taken very seriously, esp. since they are all IAS readings.

Landing speed ia absolutely nothing to turn fight because this speed is for flaps-down conditions, so it depends more on flaps effectiveness.

Take-off run is not a valuable reason because of different conditions of flight - large amount of prop slipstream downwash increasing lift and low M number.

 

As typical turnfight is performed at significantly higher M numbers, CLmax usually is significantly lower than at 1g stall and TO lift-off.

 

 

Clmax depends both on Re and M, but generally it decreases with TAS with almost constant slope for 23xxx series, for example. P-51 airfoil. though, has a very distinctive flat part at the M number range that is very useful for instant turns and for steady turns at high altitude, and this laminar airfoil is significantly better in this region than plain airfoils. Moreover - at low M it has the same Clmax as these aitrfoils.

 

That's why all rumours about "poor laminar airfoil" has no ground.

 

 

About the total turn capabilities. IN DCS Dora can steady turn having more g-load than P-51. If someone can not outturn P-51 it is not because of better Mustang's steady turn rate but because of misunderstanding how these two planes differ in their turn ability.

 

 

As P-51 has lower wing loading and almost the same maximal lift as Dora it has advantage in turn rate and turn radius in low speed range. Its thrust limited steady turn is worse than D9 turn at higher speed.

So, if Dora begins to play on Mustang's field it won't win turnfight.

THese pictures are for 61" 3000 for P-51 and Sondernotleistung for Dora. Start- und Notleistung gives the same type of advantage but not so much.

 

Except not:

 

P-51 root airfoil:

http://airfoiltools.com/airfoil/deta...il=p51hroot-il

Fw190 root airfoil:

http://airfoiltools.com/airfoil/deta...l=naca23015-il

 

NACA 23XXX Clmax = 1.5 to 1.6

NACA 66 Clmax = 1.1 to 1.2

 

As can be seen the NACA 23XXX retains the Clmax advantage at all the Mach numbers that these aircraft would concievably be flying at.

Edited April 7, 2015 by Hummingbird

The tool you use is soooo far from the test data. You easily can obtain this data. If you want.

 

What test data? 1940's test data or modern test data? I think we know which is more reliable ;)

Except not:

 

P-51 root airfoil:

http://airfoiltools.com/airfoil/deta...il=p51hroot-il

Fw190 root airfoil:

http://airfoiltools.com/airfoil/deta...l=naca23015-il

 

NACA 23XXX Clmax = 1.5 to 1.6

NACA 66 Clmax = 1.1 to 1.2

 

As can be seen the NACA 23XXX retains the Clmax advantage at all the Mach numbers that these aircraft would concievably be flying at.

Ain't NACA 66 the airfoil used by the P51H?

 

The P51H used a different airfoil from the P51D BTW.

 

http://airfoiltools.com/airfoil/details?airfoil=p51droot-il

This is the P51D's airfoil.

Edited April 7, 2015 by GrapeJam

I've got some old test results as well:

 

NACA 66(1)-212

 

 

NACA 23012

 

 

 

 

NACA 23012 CLmax @ Re 6 mill (std. roughness) = 1.22

NACA 66(1)-212 CLmax @ Re 6 mill (std. roughness) = 1.01

Again, totally irrelevant because the P51D didn't use NACA 66 airfoil.

http://airfoiltools.com/airfoil/details?airfoil=p51droot-il

 

Much closer, don't you think?

Again, totally irrelevant because the P51D didn't use NACA 66 airfoil.

http://airfoiltools.com/airfoil/details?airfoil=p51droot-il

 

Much closer, don't you think?

 

Actually the same as the real life test, the difference being a factor of ~0.2.

Actually the same as the real life test, the difference being a factor of ~0.2.

But coupled with a much cleaner airframe and a 32kg/m2 lower wing loading ;)

 

Funnily enough, the P51H actually had a very high stall speed of 102mph IAS in landing configuration, power off, at 9544lbs, compared to 101mph IAS at 10000lbs of the P51D.

But coupled with a much cleaner airframe and a 32kg/m2 lower wing loading ;)

 

The P-51D weighed 4445 kg (9800 lbs) combat ready, the Fw190D9 weighed 4270 kg (9400 lbs) combat ready.

 

That translates into wing loadings of 203 kg/m2 & 233 kg/m2 respectively.

 

Now when taking into account the difference in lift coefficients of 1.01 and 1.22 from that one chart the difference becomes:

P-51D adjusted wing loading = 201.7 kg/m2

Fw190D adjusted wing loading = 191.25 kg/m2

 

But tbh I think the adjusted wing loadings are even closer (and lower), seeing as I've got a Clmax of ~1.6 for the 190 and ~1.4 for the Mustang.

 

Remember also that it isn't in ITR that I believe that the 190 is superior, but in STR.

 

Funnily enough, the P51H actually had a very high stall speed of 102mph IAS in landing configuration, power off, at 9544lbs, compared to 101mph IAS at 10000lbs of the P51D.

 

Again, it's raw IAS, thus it tells us nothing.

Edited April 7, 2015 by Hummingbird

 

Now when taking into account the difference in lift coefficients of 1.01 and 1.22 from that one chart the difference becomes:

P-51D adjusted wing loading = 201.7 kg/m2

Fw190D adjusted wing loading = 191.25 kg/m2

Would be interested to see the formula of how you got that interesting figure.

Also in that chart of yours the NACA 23015 only got a very short moment where it clmax got slightly above 1.5

 

And I wonder why you keep using that NACA 66 chart.

 

Remember also that it isn't in ITR that I believe that the 190 is superior, but in STR.

And again this brings up the question:

 

Did you do it correctly?

 

And the P51D's airframe is extremely clean so I think you're underestimating it's energy retention in maneuver.

Edited April 7, 2015 by GrapeJam

Would be interested to see the formula of how you got that interesting figure.

Also in that chart of yours the NACA 23015 only got a very short moment where it clmax got slightly above 1.5

 

And I wonder why you keep using that NACA 66 chart.

 

Remember to take the figures for the right Reynolds number.

 

And again this brings up the question:

 

Did you do it correctly?

 

And the P51D's airframe is extremely clean so I think you're underestimating it's energy retention in maneuver.

 

Well considering that both Crumpp & Yo-Yo have the Dora-9 outturning the P-51 in STR, then yeah I'm pretty sure I got it right ;)

 

Only part where me and Yo-Yo disagree is on the Clmax figures, which will change the graph abit and mean that the Fw190 gets to its max STR abit sooner along the speed band.

 

As for the cleanliness of the P-51's airframe, you're overstating it, it doesn't have that big of an impact. By comparison the Fw190D is also a very clean aircraft airframe wise, it just doesn't enjoy the same low drag benefits at low AoAs as the P-51 because it features a conventional airfoil that is better at high AoAs instead.

Edited April 7, 2015 by Hummingbird

Remember to take the figures for the right Reynolds number.

Yep, and not seeing any significant advantage, most of the time it's 0.1-0.15

Remember to take the figures for the right Reynolds number.

 

 

 

Well considering that both Crumpp & Yo-Yo have the Dora-9 outturning the P-51 in STR, then yeah I'm pretty sure I got it right ;)

 

Only part where me and Yo-Yo disagree is on the Clmax figures, which will change the graph abit and mean that the Fw190 gets to its max STR abit sooner along the speed band.

 

As for the cleanliness of the P-51's airframe, you're overstating it, it doesn't have that big of an impact. By comparison the Fw190D is also a very clean aircraft airframe wise, it just doesn't enjoy the same low drag benefits at low AoAs as the P-51 because it features a conventional airfoil that is better at high AoAs instead.

 

Except yo-yo's FM has the P-51D out turning the 190. Yo-Yo never agreed with you that the 190 was a better turner, or are we all supposed to completely forget the previous 190 vs P-51 thread so conveniently?

 

Also, interesting how your combat weight for the P-51 is so unusually heavy. Generally combat weight for the Mustang was weight without the fuselage tank, so nowhere near 9800lbs. A P-51 with just the wing tanks would weight about 9600lbs. In DCS it weights 9550. Putting fuel in the fuselage tank made the P-51 less than ideal in a dogfight, hence why they always burned this fuel off first. It would make alot more sense if you pitted the planes at equivalent fuel weight in time. Since I dont think we have figures for fuel burn rate at WEP the next best thing would be equal amounts of fuel.

 

So for a Fw190D with max Fuel you would have about 9400 lbs as you said.

 

For a P-51 we would have a plane weighing about 9300lbs.

 

This would give approximate wing loadings of 47.7lbs and 39.5 lbs.

 

With your weights we'd be comparing a P-51 carrying 400lbs more fuel than a 190 can total, and with about 33 gallons in the notorious fuselage tank to boot. Hardly fair.

Yep, and not seeing any significant advantage, most of the time it's 0.1-0.15

 

Most the time? There are two figures, 1.01 for the NACA 66(1)-212 and 1.22 for the NACA 23012.

Except yo-yo's FM has the P-51D out turning the 190. Yo-Yo never agreed with you that the 190 was a better turner, or are we all supposed to completely forget the previous 190 vs P-51 thread so conveniently?

 

You need to read Yo-Yo's chart again, which I will repeat uses incorrect Clmax figures in favor of the P-51.

Since I dont think we have figures for fuel burn rate at WEP the next best thing would be equal amounts of fuel.

 

The fuel flow rate for the P-51D's V-1650-7 at WEP was between 194 gal per hr @ 67' HG in low blower and 187 gal per hr in high blower (corresponding figures for the V-1650-3 were 165 & 160 gal per hr):

 

Most the time? There are two figures, 1.01 for the NACA 66(1)-212 and 1.22 for the NACA 23012.

How many times do I have to tell you the P51D didn't use NACA 66(1)-212 airfoil? The XP51F/G/J did.

The P51D used this airfoil:

http://airfoiltools.com/airfoil/details?airfoil=p51droot-il

Which had a 1.3-1.4 clmax.

 

You're the one who's incorrect here.

Edited April 7, 2015 by GrapeJam

You need to read Yo-Yo's chart again, which I will repeat uses incorrect Clmax figures in favor of the P-51.

 

I have read it. And you are wrong.

The fuel flow rate for the P-51D's V-1650-7 at WEP was between 194 gal per hr @ 67' HG in low blower and 187 gal per hr in high blower (corresponding figures for the V-1650-3 were 165 & 160 gal per hr):

 

 

Anything for the 190? Id imagine it burns more fuel at power given both the higher power and higher drag.