Explain this and win the prize!

[Crumpp]

It would help a lot if you could understand what we are talking about; the K value of the FW 190 at high speed is for the Cl value about 0,17 ie not for linear stage of the Cd/Cl^2 curve while the e value for the Spitfire you quoted is for Cl 0,6.

Gripen,

What you fail to understand is that I did not do the "e" factor calculations.

Some professional aeronautical engineering firms did.  They did them for a FW-190A8 that is being restored to flight and will be flown exactly as it was in 1945.  Minus Ammunition of course, that will have to be ballasted.  

Those calculations are confirmed by another professional aeronautical engineering firm that is producing FW-190's.  When calculated as per a fully loaded WWII Air Superiority fighter version.

In the other thread your willingness to manipulate data on the Spitfire was very evident.  That puts any calculations you do under grave suspicion.  

We need just values of the K for this thread and I linked them above, you did not.

So tell me what speed is that value for "K" calculated under?  What speed is the spitfires?  In order to compare both A/C must be under the SAME conditions of flight (altitude, speed, attitude, etc).  Your putting up some nice calculations that are meaningless for comparision purposes and trying to compare.  As it seen from the math, the efficiency factor does change under different flight conditions.  

When I used the same logic and applied the "high speed" efficiency factor, using your "high speed" calculations, you call it into question.  It is the SAME logic you are using in your comparisions.


Crumpp

[gripen]

Originally posted by Crumpp
What you fail to understand is that I did not do the "e" factor calculations.

So now you change your story again. Above you claim that e factor averages 0,87 which is actually nonsense because value of the K gives directly exact value of the e, there is no need to calculate average or fit the line as alternative method.

Originally posted by Crumpp
Some professional aeronautical engineering firms did.  They did them for a FW-190A8 that is being restored to flight and will be flown exactly as it was in 1945.

Who actually did the calculation and how? Besides anyone can calculate e factor from the value of the K in less than five minutes as pointed out above. Apparently the numbers you got are wrong or the definition of the e factor is not same as in the Perkins&Hage.

Originally posted by Crumpp
Those calculations are confirmed by another professional aeronautical engineering firm that is producing FW-190's.

At least Mr. Colling from the Flugwerk told me that he has not given out any comments on e factor.

Originally posted by Crumpp
In the other thread your willingness to manipulate data on the Spitfire was very evident.

Ah, now you want to talk about other threads again, this thread is about determining e factor. All I can see here is that you continously change your story, fail to prove your arguments, give contradictory statements and create od theories on lift coefficient (see above). You have continously done similar things in other threads too.

Generally I have pointed source for all data I have used in this thread and I have given the calculations as well. You have not.

Originally posted by Crumpp
So tell me what speed is that value for "K" calculated under?

Actually the K values in the FW paper are for certain flying condition, not for exact speed. The report says climb speed ie around 250-300km/h TAS near sea level in the case of the full scale plane. The High speed value is roughly for top speed.

Originally posted by Crumpp
What speed is the spitfires?

Get the reports, the sources are given above. Generally I have used below mach 0,5 values for all calculations ie these should be quite comparable if wanted. Overall the exact speed (if below Mach 0,5) is not important if we know the Cl and/or value of the K.

gripen

[Crumpp]

So now you change your story again. Above you claim that e factor averages 0,87 which is actually nonsense because value of the K gives directly exact value of the e, there is no need to calculate average or fit the line as alternative method.

Here you drop some complete falsehood.  My story remains the same.

 

At least Mr. Colling from the Flugwerk told me that he has not given out any comments on e factor.

My God man!  Are you running around bugging folks over this?  Mr Colling and I corresponded some months ago.  His answer was he would be glad to help me out but to contact him during a specific time frame later in the year.  That time frame has not elapsed.  At this point his data will simply confirm what I already have on hand.

Now, It is NONE of your business at this point who I am contacting.  You want to find out my sources, then buy the book or DON"T for that matter.  

Gripen,  I just can't throw everything I find out on the table because it would leave nothing for the book

Who actually did the calculation and how?

See above.

or the definition of the e factor is not same as in the Perkins&Hage.

The numbers and formulas can produce variations.  That is exactly what the NASA engineer warned you about.  If you don't know the formulas behind the values produced you cannot begin to interchange values into different formulas.  They are not interchangeable.   The scales are different.

Not only that but the Polar Plots change as well.  I have at least three different sets of polar plots (Rechlin and Focke-Wulf) on the FW-190.  All are somewhat different.

That is exactly why I am hiring professionals and using only primary sources.

Using the same scale, the FW-190 is only a fraction behind the Spitfire in wingtip efficiency.

 

Generally I have pointed source for all data I have used in this thread and I have given the calculations as well. You have not.

No you haven't.  In the other thread you blatantly substituted data for the Spitfire Mk VIII and claimed it to be a Mk IX.  Throughout my dealings with you are more than willing to manipulate data to present your point of facts instead of allowing the facts to define your world.

The report says climb speed ie around 250-300km/h TAS near sea level in the case of the full scale plane. The High speed value is roughly for top speed.

Exactly.  A 50 Km window at climb speed and a "roughly" for top speed at what altitude?  Hardly exact and hardly worthy of comparison.

Overall the exact speed (if below Mach 0,5) is not important if we know the Cl and/or value of the K.

If you want to compare planes it certainly is important.  Nobody cares that when the FW-190 and the Spitfire have the same CL the spitfire's wing is more efficient.  What matters is under the SAME conditions of flight.  

Just like that NASA engineer told you.  

Crumpp

[gripen]

Originally posted by Crumpp
Here you drop some complete falsehood.  My story remains the same.

Let's look at the evolution of your story:

Crumpp 9-21-2004 11:58 AM:
"Just heard back from Flugwerk. They are building FW-190A8/N's and have restored several. According to them the "e" factor from FW documentation is:"

Crumpp 10-28-2004 02:40 PM:
"Those calculations are confirmed by another professional aeronautical engineering firm that is producing FW-190's."
 
Crumpp 10-30-2004 02:48 PM:
"Mr Colling and I corresponded some months ago. His answer was he would be glad to help me out but to contact him during a specific time frame later in the year. That time frame has not elapsed. At this point his data will simply confirm what I already have on hand."

Basicly you drop some complete falsehood.

Originally posted by Crumpp
My God man!  Are you running around bugging folks over this?

Just look their site, they have actually put up a "rumour controll" because some people tend to put words in their mouth just like you did above.

Originally posted by Crumpp
You want to find out my sources, then buy the book or DON"T for that matter.

So why are you in this discussion if you can't prove your statements?

Originally posted by Crumpp
The numbers and formulas can produce variations.

Actually we talk about just one exact dataset which gives exact value of the K, there is no variaton.

Originally posted by Crumpp
In the other thread you blatantly substituted data for the Spitfire Mk VIII and claimed it to be a Mk IX.

Please point me where I have done such claim.

Originally posted by Crumpp
A 50 Km window at climb speed and a "roughly" for top speed at what altitude?  

Well, you just can't understand the linear stage of the Cd/Cl^2 curve.

gripen

[Crumpp]

"Just heard back from Flugwerk. They are building FW-190A8/N's and have restored several. According to them the "e" factor from FW documentation is:"

No Your coming in the middle of my business and trying to claim you understand.

They did send me some documentation and  only the results.  They have not sent me the entire thing or how they arrived at that result.

Please point me where I have done such claim.

http://www.hitechcreations.com/forums/showthread.php?s=&postid=1391720#post1391720

So why are you in this discussion if you can't prove your statements

Again your implying a falsehood.  Just because I don't post data to prove anything to you does not mean it is not available.  Buy the book.

Just look their site, they have actually put up a "rumour controll" because some people tend to put words in their mouth just like you did above.

I highly doubt it is from the one email correspondance I have made with them.  They are extremely nice and very helpful folks who immediately contacted me and provided an answer with a time frame to recontact them for details.  I will contact them again during the timeframe they specified and not before.

Again, this is just a simple attempt to "smear".

Please point out your claim about thier site:

http://www.flugwerk.com/

 

Actually we talk about just one exact dataset which gives exact value of the K, there is no variaton.

Again totally not relevant to a comparision under the same flight conditions of the Spitfire and the FW-190.

Crumpp

[gripen]

Originally posted by Crumpp
No Your coming in the middle of my business and trying to claim you understand.

Plain nonsense.

Originally posted by Crumpp
http://www.hitechcreations.com/forums/showthread.php?s=&postid=1391720#post1391720

Funny, you linked your own post.
 

Originally posted by Crumpp
Please point out your claim about thier site:

http://www.flugwerk.com/

The Rumour control is in the diary page.

Originally posted by Crumpp
Again totally not relevant to a comparision under the same flight conditions of the Spitfire and the FW-190.

This has nothing to with the Spitfire. The FW datasheet gives exact value of the K and that results e factor 0,78 at linear stage of the Cd/CL^2 curve.

gripen

[Kurfürst]

I lost the track. Can somebody fill me in, what was the original question?

[Crumpp]

Just look their site, they have actually put up a "rumour controll" because some people tend to put words in their mouth just like you did above.

What are you talking about Gripen?  Your throwing out complete lies now.  The rumours are about Flugwerk's financial status and have nothing what so ever to do with anything in this or any GAME.  

As for the material I requested from them.  It is a business transaction as I am paying them for their services and experience with the type.  

Plain nonsense.

Exactly what your pedaling.  

Here Look closely at their website diary page:

http://www.flugwerk.com/new/diary/diary.shtm

Try and find anything remotely close to your nonsensical accusations.

Funny, you linked your own post.

And yours as well.  It in the thread towards the end.  Right before you panicked and started this one.

Crumpp

[gripen]

Originally posted by Crumpp
What are you talking about Gripen?  Your throwing out complete lies now.  

You claim above that the quote is from Flugwerk and that your numbers are confirmed by them. These are not true.

Originally posted by Crumpp
And yours as well.  It in the thread towards the end.  Right before you panicked and started this one.

Please show me the post where I "blatantly substituted data for the Spitfire Mk VIII and claimed it to be a Mk IX" as you claimed above.

gripen

[Crumpp]

Gripen says:

You claim above that the quote is from Flugwerk and that your numbers are confirmed by them. These are not true.

 

Email Crumpp recieved says:

I was checking my documents for the FW190 and the tip efficiency factor, or rather the Oswald Ellipse factor is about 1.15 or 0.87 depending on how you look at it. Basically it has about 15% more induced drag than a theoretical elliptical lift distribution.

Again Gripen,

You have to compare the A/C under the same flight condition.  The "e" factor will change.  Your comparison is not valid since you cannot reproduce the "e" factor for the Spitfire under the same conditions.

Crumpp

[gripen]

Well, Crumpp's quote is not from the Flugwerk as he self actually admits above.

Originally posted by Crumpp
You have to compare the A/C under the same flight condition.  The "e" factor will change.  Your comparison is not valid since you cannot reproduce the "e" factor for the Spitfire under the same conditions.

This has nothing to with comparisons or exact flight conditions, the FW datasheet gives value of 1,24 for K at linear stage of the Cd/Cl2 curve. And that results e factor 0,78 at linear stage of the Cd/CL^2 curve. There is no variation nor other answer.

gripen

[Crumpp]

This has nothing to with comparisons or exact flight conditions, the FW datasheet gives value of 1,24 for K at linear stage of the Cd/Cl2 curve. And that results e factor 0,78 at linear stage of the Cd/CL^2 curve. There is no variation nor other answer.

It has everything to do with exact flight conditions, Gripen.

There are portions of the flight envelope were the total drag of the Spitfire is greater than the FW-190's and vice versa.  The "e" factor is in fact listed on the document farther down the column.

Crumpp

[gripen]

Originally posted by Crumpp
It has everything to do with exact flight conditions, Gripen.

As noted several times above, the exact Cl value or speed value are not so important if the value of the K is for linear stage of the Cd/CL^2 curve and the speed is below compressibility speeds (say less than mach 0,5).



As can be seen and read from this scan from Perkins&Hage, the slope of the Cd/CL^2 curve is about linear between the CL^2 values 0,2 and 1,0. At climb speeds (say 250-300 km/h) the CL^2 value of the Fw 190A is around 0,25-0,5 so we don't need to know exact speed and we also know that the speed is not at compressibility area. Same is true for all the wind tunnel data I have used for my calculations.

This thread is not about comparing planes but about determining the values of the e factor of WWII fighters. Based on my calculations I can say with good certainty that the generic aspect ratio based formulas seem to give about 10% higher values of e factor than wind tunnel data. Flight tests seem to give even smaller values of e but I have too little data to say more, possibly most of the turn tests were done very close to Clmax ie not in the linear stage of the Cd/CL^2 curve.

Originally posted by Crumpp
The "e" factor is in fact listed on the document farther down the column.

Hm... at least my copy just lists detailed drag data for components, flying surface data and propeller and thrust data. Apparently you have just the headlines as you linked above.

Besides, as can be seen from the above image from the Perkins&Hage, the value of the K is all we need (which I have linked above), it gives directly slope of the Cd/CL^2 curve because:

K = 1 / (pi * AR * e)
 
gripen

[Crumpp]

Hm... at least my copy just lists detailed drag data for components, flying surface data and propeller and thrust data. Apparently you have just the headlines as you linked above.

Nope.  I have four other pages that come with it entitled "Polarenmessung in Chalais-Meudon".

Crumpp

[gripen]

Originally posted by Crumpp
Nope.  I have four other pages that come with it entitled "Polarenmessung in Chalais-Meudon".

Well, that's another report. You are most wellcome to bring in data in if you really want to discuss about the determining of the efficiency factor. The problem is that you have claimed many kind of things in this thread without anykind of proof.

gripen