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[JG4_dingsda]

Hello all!

I'm FM engineer from 1CGS and I worked with FW-190 flight model.

 

Does anybody have "P. Gross "Die Entwicklung der Tragwerkkonstruction Fw 190", Bericht 176, der Lilienthal Gesellschaft, 2 Teil, January 1944"?

 

Also if you have any additional references don't hesitate to send us. They will be helpful for future work with FW190A5.

 

This might be found here (since other reports of the Lilienthal Gesellschaft link here too):

 

Bestandssignatur: RL 39

Bestandsbezeichnung: Forschungsinstitute der Luftwaffe

Laufzeit: 1937-1944

Zitierweise: BArch RL 39/...

Benutzungsort: Freiburg

Zuständiges Referat: MA 5

 

One probably has to go there in person.

 

https://invenio.bundesarchiv.de/basys2-invenio/main.xhtml

 

[i am even inclined to give it a try, if there is nobody living in Freiburg wanting to go there]

Edited October 6, 2016 by JG4_dingsda

[=EXPEND=13SchwarzeHand]

If I may take a wild guess: This is needed for the cAoA discussion?

 

If you google this document, with the peculiar spelling mistake of the TragwerkkonstruCtion (instead of the correct spelling, which is TragwerkkonstruKtion) only two Russian forum sites show up, where the CaOa adjsutment is discussed and a reference to this document is made.

 

So maybe someone else has other information, that might be as helpful?

[Irgendjemand]

 

This might be found here (since other reports of the Lilienthal Gesellschaft link here too):

 

Bestandssignatur: RL 39

Bestandsbezeichnung: Forschungsinstitute der Luftwaffe

Laufzeit: 1937-1944

Zitierweise: BArch RL 39/...

Benutzungsort: Freiburg

Zuständiges Referat: MA 5

 

One probably has to go there in person.

 

https://invenio.bundesarchiv.de/basys2-invenio/main.xhtml

 

[i am even inclined to give it a try, if there is nobody living in Freiburg wanting to go there]

I wrote an inquiry to them asking for the document. With some luck I might be able to get a copy. For all interested here is the text i wrote:

 

Sehr geehrte Damen und Herren,

 

Ich bin auf der Suche nach einem Bericht über die Entwicklung der Tragwerkskonstruktion der Focke Wulf 190. Hier Alle Informationen, die mir zu dem benötigten Dokument vorliegen:

 

Author: P. Gross

Titel: Die Entwicklung der Tragwerkkonstruktion der Fw 190

Bericht Nr. 176 der Lilienthal Gesellschaft - 2 Teil vom Januar 1944

 

Könnten Sie mir sagen ob Sie dieses Dokument vorliegen haben und auf welche Art ich an eine Kopie des Gleichen herankommen könnte? Selbstverständlich würde ich entstehende Kosten hierfür übernehmen.

Ich benötige dieses Dokument um es einem Entwicklerteam einer 2. Weltkriegs Flugsimulation zur Verfügung zu stellen.

Ich bedanke mich im Voraus für die Kooperation und verbleibe

 

mit freundlichen Grüßen

 

Real Name

Edited October 6, 2016 by Irgendjemand

[JG4_dingsda]

 

I wrote an inquiry to them asking for the document.

 

I had a second look at that (sloppy) reference. This looks like an article in a collection. I expect it here:

 

Jahrbuch der Deutschen Akademie der Luftfahrtforschung (1938-1944); 7.1943/44. — Berlin: Dt. Akademie d. Luftfahrtforschg; München: Oldenbourg.

 

Bundesarchiv has that as well (Amtliche Druckschriften RLD 33). Maybe you can ask them to look there first?

Edited October 6, 2016 by JG4_dingsda

[Bert_Foster]

Secret RAF testing reports, lol. Publish at the height of WWII that a captured Focke climb at 1220m with 15,5m/s and at 5334m with 16,6m/s is more than stupid. You can really read how suprised RAF was at the end of the article from the flying legend.

 

Has someone this book " The Focke Wulf FW190 by Gordon Swanborough and William Green "? There should be something about British AFDU report on captured Fw 190 A 3 Werk-Nr 5313.  Telling how much superior in the most aspects to a spit 5 and again the same Focke climb data like above!

Here another book https://books.google.de/books?id=NFTEPiyEiSsC&pg=PA107&lpg=PA107&dq=Focke+Wulf+FW190++British+AFDU+report&source=bl&ots=RNWrrmHNMZ&sig=CL6KFe-17ieYRywq9EmRUIuYuO8&hl=de&sa=X&ved=0ahUKEwiE17uq4cXPAhUD6xQKHWLcCWUQ6AEIJjAA#v=onepage&q=Focke%20Wulf%20FW190%20%20British%20AFDU%20report&f=false

Here again talking a similar language like this book above.

 

In the end what tell this us the same to similar and more data can be found inside some books later published that repeat and confirm the data from the article published at the height of WWII 1943.

Yes I have both those books and neither of them contain the specific level of aerodynamic detail required.

[NZTyphoon]

Secret RAF testing reports, lol. Publish at the height of WWII that a captured Focke climb at 1220m with 15,5m/s and at 5334m with 16,6m/s is more than stupid. You can really read how suprised RAF was at the end of the article from the flying legend.

 

Why would publishing the climbing speeds of a captured German aircraft be stupid? The Luftwaffe already knew the performance of their own aircraft and by early 1943 the RAF had the AFDU & RAE reports, showing that the 190 was superior to the Spitfire V, so claiming that the RAF was "surprised" at the end of the article is stretching things just a wee bit.

Had Flight published accurate performance figures of the British and American combat aircraft - that would have been stupid!

[Irgendjemand]

I had a second look at that (sloppy) reference. This looks like an article in a collection. I expect it here:

 

Jahrbuch der Deutschen Akademie der Luftfahrtforschung (1938-1944); 7.1943/44. — Berlin: Dt. Akademie d. Luftfahrtforschg; München: Oldenbourg.

 

Bundesarchiv has that as well (Amtliche Druckschriften RLD 33). Maybe you can ask them to look there first?

Thanks Dingsda. I updated my inquiry with this information and hope they can find the document.

However I am no certain they will actually look for the document. I think the Archive is more there so you can go there yourself and look for desired documents. I dont think they have the needed personal to go and search the archives vor each and every request. So possibly we need someone that actually goes there and ties to find the document in person.

[=EXPEND=13SchwarzeHand]

I talked to Phenazepam, and it seems that the information they are looking for was the wash out and wing twist. I referred him to this document

 

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0001924000049629 (was posted in this thread before)

It contains P. Groß´s Document as a citation. It can be concluded that his info was used and replicated it the document (Ref. 22)

Phanzepam told me that the information seemed reliable and they would use it if they can´t find the original.

 

Just wanted to share this in case anyone is still planning on going through trouble finding the document, it appears that it does not seem so pressing anymore...

[JG4_dingsda]

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0001924000049629 (was posted in this thread before)

"404 ressource not found"

 

*edit: Seems that the link is not working for me. Can someone tell me the title of the document it refers to or the postnumber in this thread, so I can have a look?

*edit2: found it myself

Edited October 7, 2016 by JG4_dingsda

[Art]

"404 ressource not found"

Works for me ..

[II/JG11_ATLAN_VR]

link is ok

[WWChunk]

Just wanted to offer my thanks the community members that took the reigns on this, and got the conversation with the devs started.  I hope all of your work comes with a great outcome.  Thanks again!

[JG4_dingsda]

So possibly we need someone that actually goes there and ties to find the document in person.

Yes, that is why I registered there (and because it might be interesting to roam through that archive once)

 

Just wanted to share this in case anyone is still planning on going through trouble finding the document, it appears that it does not seem so pressing anymore...

Thanks for the info, Dreizehn. I'll probably still try to find it -- just to get to know whether I can.

Edited October 7, 2016 by JG4_dingsda

[Bert_Foster]

For What its worth A D9 Wing diagram from Jerry Crandall's book The D9 Vol I

 

Shows I think 2 Deg incidence at the root and 0 deg at a point point near the tip where it switches to 0 incidence.... The presumption that it is a linear reduction from 2 deg incidence at the root to 0 deg at the outer point then remains at 0 deg incidence to the tip.

 

Edited October 8, 2016 by Bert_Foster

[Crump]

Shows I think 2 Deg incidence at the root and 0 deg at a point point near the tip where it switches to 0 incidence.... The presumption that it is a linear reduction from 2 deg incidence at the root to 0 deg at the outer point then remains at 0 deg incidence to the tip.

 

Right.  From station 13 to 1 there is 2 degrees of aerodynamic twist.   From Station 13 to 15 there is no more aerodynamic twist.  That is the wingtip aerofoil NACA 20009 which stalls at a high Clmax and high Angle of Attack.  The Aerodynamic twist ensures the wingtip airfoil will always be at an angle of attack that is two degrees higher than the root.

 

Do you guys understand Lednicers CFD wing analysis and what it is saying?  

 

He shows the root airfoil CLmax as 1.58.  As that root stalls, the wing is stalled even though the outboard tip airfoil NACA 23009 is not even halfway towards its CLmax.  The pilot looses the ability to raise the nose.  As that root section stalls, the load is transferred outboard to the adjacent sections.  When they reach 1.58, they stall too.  When the wingroot reaches the 40% Lednicer span, it is at full stall.  The other 60% of the wing is still producing lift and flying.  That does not mean the airplane is still flying or that the nose has not dropped.  It just means the nose drop is gentle and the ailerons are effective throughout the stall.  That is reflected even in the low velocity measured at Chalais Meudon by the gentle curvature of the polar.

 

It is a measured and engineering fact the 1G stall of the FW-190 was unremarkable.  

 

The other portion of Lednicer's CFD analysis shows us that if you remove that aerodynamic twist of the wing thru aeroelasticity effects on the wing structure, then the wing airfoil sections will reach the stalling CLmax all at the same time resulting in a violent stall.

 

Measured data for the FW-190 tip Airfoil:

 

 

 

I had a second look at that (sloppy) reference. This looks like an article in a collection. I expect it here:

 

It is an article collection...it is not Focke Wulf, GmbH documents that were classified at the time.

[Crump]

The caveat "Staatsgeheimnis!" means "State Secret" and is the equivalent to a US Top Secret classification.

 

It is not something likely to be shared in an open conference.

 

[Bert_Foster]

From Station 13 to 15 there is no more aerodynamic twist. That is the wingtip aerofoil NACA 20009 which stalls at a high Clmax and high Angle of Attack. The Aerodynamic twist ensures the wingtip airfoil will always be at an angle of attack that is two degrees higher than the root.

 

I am confused. If the inner section (station 1-13) is at 2 deg incidence and the outer section  at zero degrees incidence as AOA increases would not the inner section always be at higher AOA than the outer section ?

 

 

Is not the most common purpose of washout to get the inner section to reach critical AOA first ?

 

For my benefit what is the critical AOA of the inner section NACA 23015 and the the outer NACA section 23009 ?

 

Edit:

As far as I can deduce NACA 23015 critical AOA is around 18Deg and NACA 23009 is around 20deg. This implies that as AOA increases the washout will cause both the inner and outer sections to reach their respective critical AOA's at more or less the same time ?

Edited October 8, 2016 by Bert_Foster

[JtD]

No, the angle of incidence at the root was larger than at the tip, as it normally is. So in addition to the (depending on source) 1 or 2 degrees you might get from the profiles, you'll also have the 2 degrees of washout delaying the stall at the wing tips.

[Bert_Foster]

Yes I get that JTD (hence why I responded to Crumps statement which is the exact opposite). So if the same aerofoil was used both inner and outer (no washout) then (not allowing for tip dynamics etc) then in simple terms the wing would stall uniformly along the span.

 

Introduce the 2 deg of wash out with the same section along the span then yes the inner section will reach critical AOA first and stall first ... the traditional affect of washout giving aileron control right at the root stall.

 

Now change the outer section to an aerofoil that has a 2 deg greater critical AOA than the inner section ... will that not offset some of the inner section 2 degree higher incidence ?

[Crump]

I responded to Crumps statement which is the exact opposite

 

What?  What I said is correct and the in this case, the same.   I have no idea what you are reading or thinking.

 

 

 

That is the wingtip aerofoil NACA 20009 which stalls at a high Clmax and high Angle of Attack.  The Aerodynamic twist ensures the wingtip airfoil will always be at an angle of attack that is two degrees higher than the root.

 

 

 

So in addition to the (depending on source) 1 or 2 degrees you might get from the profiles, you'll also have the 2 degrees of washout delaying the stall at the wing tips.

 

 

Edit: As far as I can deduce NACA 23015 critical AOA is around 18Deg and NACA 23009 is around 20deg. This implies that as AOA increases the washout will cause both the inner and outer sections to reach their respective critical AOA's at more or less the same time ?

 

Totally wrong. 

[Bert_Foster]

Crump you said:  "The Aerodynamic twist ensures the wingtip airfoil will always be at an angle of attack that is two degrees higher than the root."

 

So does that not imply that that the Tip section will stall first ? ..... since the root according to you is at a lower AOA than the tip.

 

1. So enlighten me What are the Critical angles for each section ?

 

2.Do you agree that the inboard sections Station 1-13 are at 2 degrees incidence ?

 

3. Do you agree that the outboard stations from 13 to the tip are at zero incidence ?

 

If so then does that not then mean that the Inner section will always be at a higher AOA than the tip section by way of its 2 degree incidence ?

[Crump]

 

 

So does that not imply that that the Tip section will stall first ?

 

 

Ha ha ha...sorry man.  Dyslexia set in!

 

It is correctly described below...in the same post and quoted:

 

 

 

 

He shows the root airfoil CLmax as 1.58.  As that root stalls, the wing is stalled even though the outboard tip airfoil NACA 23009 is not even halfway towards its CLmax.  The pilot looses the ability to raise the nose.  As that root section stalls, the load is transferred outboard to the adjacent sections.  When they reach 1.58, they stall too.  When the wingroot reaches the 40% Lednicer span, it is at full stall.  The other 60% of the wing is still producing lift and flying.  That does not mean the airplane is still flying or that the nose has not dropped.  It just means the nose drop is gentle and the ailerons are effective throughout the stall.  That is reflected even in the low velocity measured at Chalais Meudon by the gentle curvature of the polar.

 

 

It should correctly read:

 

"The Aerodynamic twist ensures the wingtip airfoil will always be at an angle of attack that is two degrees lower than the root."  

 

 

 

If so then does that not then mean that the Inner section will always be at a higher AOA than the tip section by way of its 2 degree incidence ?

 

Yeah that one statement was wrong.  However, if you read the rest of the post, it was explained correctly. 

I am sure that was confusing.

[Bert_Foster]

Goodo we are now on the same wave length.

 

Now so I can get this straight in my head what are the Critical angles for each section used ? just trying to figure out the stall progression pattern from root to tip.

[Crump]

just trying to figure out the stall progression pattern from root to tip.

 

That is shown in Lednicer's article you posted a snippet from.  That is the diagram Figure 12.

 

Do you need the entire thing?

[Bert_Foster]

no I have it will re read.

[NachtJaeger110]

Hey guys,

 

I found the report and sent a copy to Phenazepam

 

correct citation is:

 

P. Groß: Die Entwicklung der Tragwerkkonstruktion FW 190. In: Lilienthal-Gesellschaft für Luftfahrtforschung. Bericht über die Sitzung der Arbeitsgruppe Tragwerk in der Entwicklungsgruppe Bauweisen der Flugzeugzelle des Reichsministers der Luftfahrt und Oberbefehlshabers der Luftwaffe am 21. und 22. Januar 1944 in Oberammergau. Bericht 176 / 2.Teil, S. 70-85.

 

PM me if you'd like to read it, too

Edited October 11, 2016 by NachtJaeger110

[Irgendjemand]

Hey guys,

 

I found the report and sent a copy to Phenazepam

 

correct citation is:

 

P. Groß: Die Entwicklung der Tragwerkkonstruktion FW 190. In: Lilienthal-Gesellschaft für Luftfahrtforschung. Bericht über die Sitzung der Arbeitsgruppe Tragwerk in der Entwicklungsgruppe Bauweisen der Flugzeugzelle des Reichsministers der Luftfahrt und Oberbefehlshabers der Luftwaffe am 21. und 22. Januar 1944 in Oberammergau. Bericht 176 / 2.Teil, S. 70-85.

 

PM me if you'd like to read it, too

Great Job!

 

Thanks a lot!

[II/JG11_ATLAN_VR]

 

[Crump]

just trying to figure out the stall progression pattern from root to tip.

 

Great Job Nachtjager in finding the report.  

 

 

Author: P. Gross

Titel: Die Entwicklung der Tragwerkkonstruktion der Fw 190

Bericht Nr. 176 der Lilienthal Gesellschaft - 2 Teil vom Januar 1944

 

 

Is a article about the construction techniques of the FW-190 wing and some of the design choices used for the FW-190V1, FW-190A1, and Ta 152H.  

 

What it basically says is that Focke Wulf designed the wing with an eye on torsional stiffness and was willing to accept a weight increase to maintain high levels of stiffness.  Torsional stiffness and reducing torsional losses is a key parameter in wing design if we want to design an agile aircraft.

 

In the article, two wings are compared for span loading characteristics and torsional stiffness.  One is the FW-190 wing and the other a comparison design.

 

Figure 1 shows are our two wings, clearly labeled FW-190 wing and comparison wing:

 

 

Figure 2 shows us the span loading and defines the configuration of the wing.  Bert_Foster, this what shows us the stall progression of the wing. 

 

 

The wing is the clean FW190 wing without flaps.  The chart is set with the Coefficient of Lift required for flight as 1.  This makes for easy comparison of which portion of the wing is carry the largest load in flight.  The portion carrying the largest load is at the highest coefficient of lift and is the part of the wing that will stall first.

 

With the 2 degrees of aerodynamic twist the chart shows the span loading is shifted inboard.  Our wing root will stall first and our outboard wing sections will remain flying.  This is a normal stall with the nose dropping when the root reaches CLmax and our pilot retains some degree of aileron control throughout the stall.

 

With the aerodynamic twist removed, the span loading is shifted outboard.  It is the wing tip that will stall first resulting in a loss of aileron control and an uncontrollable rolling moment towards the stalled wingtip.  Tip stalls are not desirable.

 

Figure 3 shows the load distribution at various Coefficients of Lift and in turning flight in order to compare to torsional stiffness.

 

 

It is the heart of the debate of "what is the CLmax of the FW-190 wing and in what configuration".

 

Case A represents the wing at CLmax.  The comparison wing has been set a calculated CLmax of 1.5.

 

 

 

Im A-fall würde das flügelende des vergleichsflügels gegenüber rumpfmitte von 3 auf etwa .2 hochdrehen.  Daraus ergibt sich eine ca belastung, die offensichtlich zum beginn der strömungsablösung im querruderberich führen dürfte Der A-Fall wurde mit einem Auftriebsbeiwert des flügels von 1.5 gerechnet, da hierfür bereits vergleichsuntersuchungen der FW190 vorhanden wraen.  Der übliche ca wert von `1.6 könnte bei der angenommenen verwindung gerade etwa erreicht werden infolge des elastischen aufdrillens Flügels und ohne erhebliche gefahr des abkippens;  der unverwundene flügel dagegen gerät durch das aufdrillen am flügelende in das überzogene anstellwinkelgebiet und kann daher keinen nennenswerten ca-gewinn mehr aufweisen.  Er ist aber dabei in erhöhtem maße der gefahr des abkippens ausgesetzt.

 

 

 

 

The A-case (for the comparison wing) was calculated with a wing lift coefficient of 1.5, since comparative studies of the FW190 already exist. The usual ca value of `1.6 (for the FW190 wing) could be achieved by the elastic twisting of the wing and without a significant danger of the tip stalling;  the untwisting of the wing by the twisting at the end of the wing into the critical angle of the angle of attack and therefore making any Ca profit insignificant (tip stalling explained for the reader).   However, it (the comparison wing) is moreover exposed to a risk of tip stalling.

 

So there is no question that a CLmax of 1.58 represents the clean wing.  It is NOT the landing configuration CLmax (stall point).

 

In Figure 3, turning flight was examined at a coefficient of Lift of 1.25.  

 

This is NOT the CLmax in turning flight.  It is just the number they stopped measuring the torsional stiffness characteristics in a turn because it did not make sense to continue.  The measured results gave them no reason to think the span loading would significantly change.  The wings torsional stiffness will mimic the A-case span loading distribution.

 

 

 

Der kurvenflug mit ca 1.25 is unbedenklich, für größere ca-werte wurde er nicht untersucht, jedoch is anzunehmen, daß bei größeren ca-werten die K-verteilung sich der a-verteilung nähert.

 

 

 

 

Turning flight with approx. 1.25 is safe, for larger coefficient of lift values ​​it was not examined, but it is assumed that with larger coefficient of lift-values ​​the K-span loading distribution is approaching the A-span loading distribution.

 

The full benefit of a high CLmax of the airfoil selection can be realized out of the wing design in all conditions of normal flight.  There is no evidence to suggest otherwise.  This is very much in keeping with the anecdotal evidence for the unusual accelerated stall characteristics provided by Luftwaffe veterans.   The "escape maneuver stall" entry requires hard rudder input representing asymmetric flight at significant G-load.

 

The lower graph in Figure 3 shows the degree of wing tip movement and twisting forces on exerted on the wing.  Examining the data makes it very obvious that Focke Wulf's construction decisions were sound.

 

So, Focke Wulf GmbH data agrees with Grumman for a wing design of the same airfoil selection and with a modern day CFD analysis.

 

There is no doubt that 1.58 is the clean wing CLmax of the FW-190A series and Dora 9.

[Crump]

Control inputs for harsh accelerated stall of the FW-190:

 

1.  Stick pulled back to load the airplane (PULL some G's)

 

2.  Hard rudder input on the wing you want to stall (Asymmetrical G-loading)

 

 

Control Inputs required for a Snap Roll (Asymmetrical G-loading accelerated stall)

 

1.  Stick pulled back to load the airplane (PULL some G's)

 

2.  Hard rudder input on the wing you want to stall (Asymmetrical G-loading)

 

 

Kind shows us a pattern...Mmmmmm

[PB0_Foxy]

Very interesting stuff !

Thx for the sharing and the analysis

[JtD]

Is a article about the construction techniques of the FW-190 wing and some of the design choices used for the FW-190V1, FW-190A1, and Ta 152H.

Thank you for taking the time to present a summary of the article for the English speaking audience. I would, however, like to add/correct some points to the ones you've presented.

 

What it basically says is that Focke Wulf designed the wing with an eye on torsional stiffness and was willing to accept a weight increase to maintain high levels of stiffness.

What it basically says is that the new construction ("Schalenbauweise"/stressed shell) offers higher torsional stiffness and damage resistance at a reduced weight compared to a conventional construction ("Holmbauweise"/spar construction).

 

Figure 2 shows us the span loading and defines the configuration of the wing.

Figure 2 shows the conventional, comparison wing. You description is right, but the article doesn't refer to the Fw190 wing.

 

Figure 3 shows the load distribution at various Coefficients of Lift and in turning flight in order to compare to torsional stiffness.

Fall A is the maximum lift coefficient obtained at the lowest speed at which maximum permissible g can be obtained, Fall B is the lift coefficient at maximum g at 0.8 maximum permissible ram pressure (~0.9 max. permissible speed (vne)). Both cases are safety relevant structural strength calculations. The values are theoretical and caTrmax is defined as "the maximum stationary lift coefficient of the aircraft normalized to the wing area". Typically, a caTrmax of 1.6 was used at the time. All results are calculated, none are measured. Assumptions are on the conservative side in order to not jeopardize safety margins.

 

The key points in figures 3 are:

Less torsion in the Fw190 wing than there is in the conventional wing.

Safe stalling behaviour of the Fw190 wing when compared to the conventional wing, because even under high loads the Fw190 wing stalls root first, where the conventional wing starts to stall tip first (A-Fall).

Slight reduction in maximum obtainable lift coefficient for the conventional wing, since the large wing area near the root can no longer be brought up to clmax.

 

About your summary - engineers don't do structural safety calculations for a clmax of 1.5 and then have the aircraft fly around with a clmax of 1.58. Doesn't happen.

Edited October 13, 2016 by JtD

[Irgendjemand]

I really hope this finally leads to a change in current and future FW 190 FM modelings.

Edited October 13, 2016 by Irgendjemand

[Crump]

NzMax (Maximum Allowable Load Factor) = Lift required maximum / Weight = (1/2pV^2)/(W/S) * CLmax

 

When Lift Required equals Weight....Our load factor is 1 and we are at the lowest possible airspeed for the maximum permissible "g load" that can be obtain.

 

 

 

You got it JtD or do you need me to walk you through it?

[JtD]

The text says 1.5 is being used because corresponding investigations for the Fw190 wing have already been carried out. The chart can be read as 1.6, however, the scaling clearly shows it's 1.5 - in agreement with the statement in the text.

 

As you may have noticed, the article is about structural strength and in particular wing twist. Everything related to structural strength is different at 6g when compared to 1g, including wing twist. Knowing what Fall A and B refer to is extremely relevant for the proper interpretation of the shown results.

[Crump]

 

 

The text says 1.5 is being used because corresponding investigations for the Fw190 wing have already been carried out.

 

Not a complete translation.

 

 

 

 

Im A-fall würde das flügelende des vergleichsflügels gegenüber rumpfmitte von 3 auf etwa .2 hochdrehen.  Daraus ergibt sich eine ca belastung, die offensichtlich zum beginn der strömungsablösung im querruderberich führen dürfte Der A-Fall wurde mit einem Auftriebsbeiwert des flügels von 1.5 gerechnet, da hierfür bereits vergleichsuntersuchungen der FW190 vorhanden wraen.  Der übliche ca wert von `1.6 könnte bei der angenommenen verwindung gerade etwa erreicht werden infolge des elastischen aufdrillens Flügels und ohne erhebliche gefahr des abkippens;  der unverwundene flügel dagegen gerät durch das aufdrillen am flügelende in das überzogene anstellwinkelgebiet und kann daher keinen nennenswerten ca-gewinn mehr aufweisen.  Er ist aber dabei in erhöhtem maße der gefahr des abkippens ausgesetzt.

 

 

 

The A-case (for the comparison wing) was calculated with a wing lift coefficient of 1.5, since comparative studies of the FW190 already exist. The usual ca value of `1.6 (for the FW190 wing) could be achieved by the elastic twisting of the wing and without a significant danger of the tip stalling;  the untwisting of the wing by the twisting at the end of the wing into the critical angle of the angle of attack and therefore making any Ca profit insignificant (tip stalling explained for the reader).   However, it (the comparison wing) is moreover exposed to a risk of tip stalling.

 

It is actually quite clear and quite standard.  You can even see the Focke Wulf curves are exactly reproduced by David Lednicer's Independent CFD analysis.

 

 

IN THE REPORT THE FW190 is clearly labeled as the FW190 wing and shows a Clmax of 1.6.  Why would they calculate out a Clmax of 1.5 when they already have plenty of studies and data on the wing!  In other words, you are saying the sentence should be translated as:

 

"We calculated the wing of the FW-190 Clmax to be 1.5 despite having mounds of measured data at our disposal and then to further confuse you, we labeled the graph 1.6....

 

I do not think your translation is correct nor is it passing along the ideas presented in the report.

 

 

As you may have noticed, the article is about structural strength and in particular wing twist.

 

As you noticed how airplane science works:

 

 

 

NzMax (Maximum Allowable Load Factor) = Lift required maximum / Weight = (1/2pV^2)/(W/S) * CLmax   When Lift Required equals Weight....Our load factor is 1 and we are at the lowest possible airspeed for the maximum permissible "g load" that can be obtain.

 

Our structural load has a direct relationship with 1G CLmax.....

 

In fact....it is the same value. 

[Stig]

Does this finally settle the debate? Who's right? It can be confusing for the non experts. 

 

You wish

[Crump]

Does this finally settle the debate? Who's right? It can be confusing for the non experts. 

 

 

i am sure it can and it is a real shame, too.  

 

As far as the question of what is the CLmax for the FW190 clean wing, that is a done deal.

 

It is a fact it is 1.58.

 

Whether JtD realizes it or not is another question.  He is absolutely right that the report is an investigation into the structural limits of the aircraft.  He just does not understand aircraft flight mechanics to know the special relationship that CLmax (stall point) has with the structural strength of the design.

 

 

 

So how do we protect the air-frame from exceeding these extremes? By stalling the wings, a stall is a form of aerodynamic relief and prevents additional maneuvering loads from being applied. This is where maneuvering speed enters the mix. VA or maneuvering speed is the speed calculated by the manufacturer at which the aircraft will stall before exceeding maximum G loading, thus preventing damage to the air-frame.

 

 

 

Maneuvering speed is usually determined by multiplying the flaps-up, power-off stall speed by the square root of .....

 

The structural load limit!!!!

 

http://www.lapeeraviation.com/maneuvering-speed/

Edited October 13, 2016 by Crump

[Crump]

Ok, where do we submit the report to the devs?

[DD_Arthur]

Ok, where do we submit the report to the devs?

 

PM Han with your report.  It has to be sent in a certain format.  Here's what Han says you must do;

 

 

Anyway, as I've said many times before, rule is: in my PM box should be a message where will be:

1. Claim detailed decription, which explain all aspects of the claim

2. Supporting historical technical sources like flight manuals, flight test reports and so on, with strict pointing page and line where we should look for proofs

3. Strict flight tests in game, which shows significant difference between game and historical source.

If it is - we start to investigate the claim. Two finals are possible:

1. We provide "our FM is ok" proofs

2. We fix the issue

I'm hope it's clear. And, actualy, it works.