Fw-190 Dora-9 vs P-51D Mustang

[paul.kachurak]

Soren,

I am not going to get into an argument. I have the documentation for a Jumo 213A w/ MW50 giving 2100 PS. If you want I will e-mail that to you or anyone who wants to see. I do not have documentation at all for a 2240 HP Jumo 213A with any boost. If you have documentation that shows without a doubt that a Jumo213A was capable of providing 2240 HP not PS horsepower then please show me. I want to believe. But after three years of looking, and asking, and analyzing it I need to see the documentation.

[Erich]

deleted

Erich ~

[Erich]

intersting just checking through data on the engines of the Ju 88G-6. not bad for an old hunk of bolts. 2 Jumo 213E's with 1,880 h.p. up to 2,250 h.p. rating when needed...............

E ~

[KraziKanuK]

Came across this site, http://www.dauntless-soft.com/PRODUC...HandlingNotes/

Many, many pdf files of 'Pilot Notes'.

Soren, there is an extensive American report on the Kommandogerat which says the same as what Lunitic says. http://naca.larc.nasa.gov/reports/19...umbnail1#start

[JonJGoldberg]

...Great reading guys.
paul.kachurak welcome.

As some of you may know, I've posted a fighter comparison table containing much of this data, although it is data presented rather differently, it is contained within the best fighter thread, paul please download it here, http://www.ww2aircraft.net/forum/vie...=962&start=520, look for the .pdf

I run a lighting automation technology & integration division by trade, so this is a hobby for me; I’ve loved WW2 aircraft since seeing an F4U Corsair as a tot. I bought Microsoft CFS-1 in ’99, then CFS-2 in 2000. After about a year of tinkering, & the discovery of a marvelous spread sheet designed by Jerry Beckwith, I decided to acquire as much data as possible to generate as close as the CFS-2 platform would allow, ‘air’ files for as many aircraft as possible. You will find post upon post of how and where information was acquired if you decide to go backwards from where I pointed you above, you may also find a great deal of additional data on a ‘dead’ thread F4U-4 Vs P-47N & acknowledgements in the spread sheet, so I will end the description here with regard to ‘validation’ issues that may arise from this point forward.

One of the great things, I’ve come to learn, about this site is that these forums can really open your mind, as ‘peer’ pressure can at times be a great motivational force generating the momentum needed to gather data you might otherwise let go by, & accept viewpoints never before entertained.

With regard to viewpoints: According to my tables the variance in my ‘weighted’ performance charts shows the aircraft (the 51 & 190 Ds) to be real darn close overall. I believe, as you seem to, that the two are two close to call, & if combat were to start with neither aircraft at an advantage, the contest would be decided by ‘human’ factors, the pilot’s skill, knowledge, his (or her) application of them, & his (or her) composure.

I would like however to mention, your charts are beautifully done, & that you are applying your data incorrectly. For example, the turn charts although at 1st pass they looked good, and the planes seem able by math to do what your tables suggest, but at 340 MPH, you’ll rip the wings off these birds, even if empty, as you have exceeded the airframe’s stress ratings. I also need some clarification please… CL is a dimensionless quantity – the lift coefficient – which relates mostly to the angle at which the wings meet the airflow or flight path, but also to the shape of the wings particularly in cross section – the aerofoil. What exactly is CLmax? I calculated CL for the P-51 as 1.476 & the 190D9 as 1.766 for my tables… But I’m not looking to split hairs here, I just want to know what CLmax is.

With this in mind please have a look below… (Graph images derived from spread sheets created by Jerry Beckwith; Other tables from P-51 flight manuals)

[FLYBOYJ]

Originally Posted by JonJGoldberg

I would like however to mention, your charts are beautifully done, & that you are applying your data incorrectly. For example, the turn charts although at 1st pass they looked good, and the planes seem able by math to do what your tables suggest, but at 340 MPH, you’ll rip the wings off these birds, even if empty, as you have exceeded the airframe’s stress ratings.

Nice information guys and nice to see you posting again JJ. When you say his charts are wrong are you speaking in terms of True Air Speed vs Indicated Air Speed? For example in the portions of the P-51 -1 JJ posted it shows Indicated Airspeed limiatations at altitude, have you done an example to see what the "True Air Speed" would be at sat 25,000 feet with the outside air temperature at -20F? It could be done with one of these....

[lesofprimus]

Great info right there guys, good one Jon...

[pbfoot]

when all these numbers for airspeed are cited are they all using the same criteria like humidity and temperature on the charts there is no reference given to these important variables

[paul.kachurak]

Jon,

Thanks for the information.

I use true airspeed for all my calculations not indicated airspeed.

I guess I don't understand why you say I will exceed the aircraft limitations when I purposefully limited the max g to 6 not to represent the limits of the aircraft but rather the limits of a human without a g suit.

Here is what I used for the Fw190D-9
gross weight = 9147 lb (68% fuel, full ammo)
CLMAX = 1.58
wing area = 197 sq ft

I don't see in your graphs what the weight, wing area, or CLMAX is. You do need all those things. Further I don't know what altitude you are looking at because all that will change with altitude.

But let me run through and example...

First to let you know my background I am an aerospace engineer who works for the USN. I have been involved with aircraft mass properties for about 15 years. I don't do aero performance but it is my hobby, too.

So using the above data for the D-9 and using sea level (soory for not knowing how to du greek symbol on a forum like this)
air density (rho) r = 0.002376 slugs/ft^3

We know that Lift (L) = load factor (n) * weight (W)

And we know that L = 0.5 * r * V^2 * S * CL so we have all we need to solve for speed in ft/s for any load factor at the CL we want to use CLMAX. This will give us for the peak n the instantaneous load factor from which we can find instantaneous turn rate, which is what your chart shows.

So
n = 6
W = 9147
S = 197
r = 0.002376
CLMAX = 1.58

6 * 9147 = 0.5 * 0.002376 * V^2 * 197 * 1.58

Solving for V we get 385.25 ft/s = 262.67 mph = 422.7 kph

In the plot I show at 5000m. Here's the numbers I used for that:
n = 6
W = 9147
r = 0.001428 (std atmosphere air density at 5000m)
S = 197
CLMAX = 1.58

Solving for V = 496.9 ft/s = 338.8 mph = 545.2 kph

I repeated this same process for other altitudes I never went over 6 gs for either the Fw190D-9 or the P-51D. If you'd like to see my Excel file I would be more than willing to send it to you. It's not so user friendly. No two engineers think a like.

Those plots look a lot like the ones that the CFS2 1% group make. Is that where you got them? I have those, too. In fact I'm looking at them right now and I can't tell what weight they use. Take a look in the upper left hand corner of the Turn Performance spreadsheet and you'll see CLMAX of 1.58. In that CFFS2 1% workbook you'll see that those guys also calculate the airplane CLMAX from the airfoil CLMAX. Very cool stuff and I was glad to see their calculations match the FW number of 1.58. I have the P-51D-30 CFS2 1% stuff too and they calculate a CLMAX of 1.48.

CLMAX is the maximum lift coefficient that an airplane or airfoil can produce before the wing stalls and the lift drops off. It is so hard to find a good definition of what the lift coefficient is. I understand what it is but giving a good definition is hard. None of the texts I have from college really give a good layman's definition. Lift coefficient CL is most simply put it is the non-dimensional (meaning it has no units like feet or meters) measure of lift capability. CLMAX is the upper bound on this capability. You get different CLs at different angles of attack given a constant speed. Make any sense? If you are really interested I recommend picking up some texts like "Theory of Wing Sections" by Abbott and vonDoenhoff, "Aerodynamics for Engineering Student" by Houghton and Carruthers, or "Aerodynamics for Engineers" by Bertin and Smith. All will put you to sleep in 3 minutes. But that's what I have from school.

Oh here's one "Aerodynamics for Naval Aviators". I'll bet they make it so simple even a nugget pilot can understand .

"Lift coefficient" would be the ratio between the lift pressure and dynamic pressure;...The use of the coefficient form of an aerodynamic force is necessary since the force coefficient is:
(1) and index of the aerodynamic force independent of area, density, and velocity. It is derived from the relative pressure and velocity distribution.
(2) Influenced only by the shape of the surface and angle of attack since these factors determine the pressure distruibution
(3) an Index which allows evaluation of the effects of compressibility and viscosity. Since the area, density, and velocity are opbviated by the coeffcient form, compressibility and viscosity effects can be separated for study."

CLMAX occurs at the minimum speed for a given lift requirement.

[paul.kachurak]

once I receive the Jumo stuff I will delete my thread.

if you would please.... ?

many thanks

Erich ~[/quote]

Erich,

I will-do tonight when I get home.

[paul.kachurak]

Originally Posted by Erich

intersting just checking through data on the engines of the Ju 88G-6. not bad for an old hunk of bolts. 2 Jumo 213E's with 1,880 h.p. up to 2,250 h.p. rating when needed...............

E ~

I agree. I have a Jumo213E1 power plot, too. But the Jumo213E1 was not installed in the Fw190D-9. It was installed into the Ta-152.

One must remember that Kurt Tank considered the D-9 as an interim solution until he could get his real high altitude plane developed. If you don't have it I recommend "Focke-Wulf Fw 190 Long Nose" by Dietmar Hermann available at Schiffer Books http://www.schifferbooks.com/newschi...sbn=0764318764

It is chock full of great development history. The seemingly painful situations that the RLM put Focke Wulf through. Good pilot accounts. IMO a great book for the Longnose 190 enthusiast.

[paul.kachurak]

Aww hell I am 99.99% sure I got these off of the internet so I'll post them. The first is the drag data. Also on there is camax aka CLMAX. You will also see about 2/3 of the way down under the D-9 column and on the Nstart row that with MW50 the power is 2100 PS. I have a power curves for a Jumo213A that show 2100 PS that I cannot post that IMO confirm this power. The second has speeds and climbs. This second matches well with the 11 Mar 45 sheets I have which I also cannot post.

[Erich]

Paul yes I have the Dietmar book, nice tech book, not the best for personal accts in my opinion. I was fortunate to chat with Will Reschke, quite an outstanding pilot and gentleman. Quite the stories too. E.E was suppose to have a book out just on JG 301 with unpublished info on the Tank but it appears it will be at leat the Tank info in EE's book on the Dora that I have placed in an earlier thread in this section ............

can you post the power plot on the Jumo E maybe in a new thread as I do not want this interesting thread to go off topic ?

thanks in advacne for the information via e-mail

E ~

[syscom3]

It would be great if the charts were translated to english using US weights and speeds.

[KraziKanuK]

1kg = 2.2lb
100kph = 61mph