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303_Kwiatek

Some data comparison between FW 190 A-3 vs Yak-1 (1942)

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Anyone got this document and could give some brief overview ? 

 

 

http://forum.il2sturmovik.com/topic/21732-whats-your-opinion-new-fw-fm/page-21?do=findComment&comment=376281

 

This you have seen?

 

It would be interessting seeing the whole report (if there is more), not just this:

http://forum.il2sturmovik.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=23034

 

Z

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Must have missed that one, thank you for the link Zacharias !

 

Should be in some archives ? I dont know much about researching German aircraft, point me a Japanese stuff and I will spend next week hidden alone and searching for documents. But my friend from Switzerland used to have good relations with Bundesarchiv.

Anyhow, it seems that case is to bust incorrect document but has to be done with proper documentation. 

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I wonder what previous data was based on? 

 

Also some customers explain that could be error in anayzing documents which used developers to change Clmax and cAoA in last update:

 

Developers reconfigured Fw-190 on the document:

post-2090-0-02341300-1470820990_thumb.jp

This purging of the aircraft in a wind tunnel at Chalais Meudon. The critical angle of attack is 15.5 degrees. But the Germans made a mistake. They are not correctly defined correction factor. In repeated trials, they found that the angle of the amendment should not be 1.5 degrees. The amendment should be 0.25 degrees. This report was created by them "Messungen an einer Fw 190 im grossen Windkanal von Chalais Meudon bei Paris", Focke-Wulf Bericht Nr.06006, 1943". Developers obviously this is not taken into account. The critical angle to be 16.75 degrees, rather than 15.5. That is, the plane should be a little more stable in extreme turns.

We have sent a report on this issue. I hope someday they will consider it.

 

 

So Germans found error in mentioned data and made correction in 1943?  Why developers dont take it?

 

Also i think Crump made some good calcuation how Clmax and cAoA should looks in Fw 190 A. 

 

Developers reject these reports.

 

Wonder which data  DCS FM developers used for their D-9 as it had the same wing profile as A version. D-9 in DCS behave much more beliveable to me then A-3 in BOS.

Edited by 303_Kwiatek

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Perhaps developers reject these reports because they like how the plane behaves ingame in its current state ?

 

Excuse me but, when you can see Han saying "+1 i agree with you at 100%" when someone says "Fw 190 was a ground attacker on eastern front for a reason xd" (pretending, bad fighter), you can only ask you some questions...

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Unfortunately such attitude is obvious since relase of these plane all changes for more historical (which was equal better performance) was really paintfully for developers. It looks that it wasnt change and will not change in the future.

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Perhaps developers reject these reports because they like how the plane behaves ingame in its current state ?

 

Excuse me but, when you can see Han saying "+1 i agree with you at 100%" when someone says "Fw 190 was a ground attacker on eastern front for a reason xd" (pretending, bad fighter), you can only ask you some questions...

Could you show me the link where Han said this?

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:o: is this real?

It is, unfortunately. That's why most of our squadron lost faith and don't want to invest in any alpha sequel. But just wait a bit and Luke Skywalker will arive and telling you everything is perfect and you just have to bring evidence...

 

Hopefully things change with Jason in the lead, but do you know Goethes Faust: I hear the message well but lack Faith's constant trust.

 

Well, we will see

Edited by StG2_Manfred

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I´m sorry if this has been discussed before, but I thought someone sent a report on the faulty measurements of Chalais Meudon tests to the devs. What happened to that? Did it just get ignored?

 

I always thought that the corresponding NACA airfoils used were studied very intensively and that there are actually a whole bunch of reports available regarding them. Why is is that the devs rely on the ONE faulty test that is out there and disregard all the other numerous tests that have been made? IMHO this is ridiculous! Just by cross checking their parameters for different AC it should be absolutely clear that what they are doing is not plausible at all...

Edited by II/JG17_SchwarzeDreizehn

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I´m sorry if this has been discussed before, but I thought someone sent a report on the faulty measurements of Chalais Meudon tests to the devs. What happened to that? Did it just get ignored?

 

I always thought that the corresponding NACA airfoils used were studied very intensively and that there are actually a whole bunch of reports available regarding them. Why is is that the devs rely on the ONE faulty test that is out there and disregard all the other numerous tests that have been made? IMHO this is ridiculous! Just by cross checking their parameters for different AC it should be absolutely clear that what they are doing is not plausible at all...

 

What I would like to see even more is WHAT REPORT have been sent to the devs ???

 

There are a lot of people claiming to have sent a report about FM issues, I've yet to see a single one of these reports.

Because out of these people, some can be very caustic in their tone and if their reports are made the same way they are posting on the forum, no wonder they got ignored.

 

Moreover they are very incline to quote the answer they received, but when it comes to what they sent, this is always top secret.

Why are these people so reluctant to expose that to the community ? What are they afraid of ?

A community based report would have more chances to hit the nail than people individually sending their own.

 

In a lot of FM discussion, it turns out that everybody makes sometimes misconceptions, calculations mistakes and false assessments.

So if each reports is right on some points but contains flaws in the reasoning, it will most likely be discarded.

If the people could finally discuss the matter openly and sending a rock solid report, constructed collectively, we may finally see a revision of the FM.

 

Otherwise it will be the same story again and again of people talking trash on each other and quoting the same arguments, the same stories from pilots and the same graphs to no avail.

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What I would like to see even more is WHAT REPORT have been sent to the devs ???

 

 etc

 

I sort of agree, at least that people who post their "reports" to Han in PM should also post them in the FM section too. (I have always wondered why this does not happen - perhaps the Russians do it and we simply miss it).

 

The idea that the "community" can come up with an agreed consensus report, however, flies in the face of experience. In theory, an open report will be better because the every one has both random noise and some pieces of useful signal in what they have to say. If the noise is random, it cancels out and the signal is left. But this only works, (if at all), if the individual signals are collected independently and then aggregated.

 

The problem here is that 1) the noise is not random: there are lots of people with preconceived agendas and b) many of the people transmitting with the loudest signal have no idea how to present a rational case, so any "community report" would simply descend into a power struggle over final editing rights.

 

Better to stick with the "experts", (hopefully excluding those who claim to be such while incapable of calculating the area of a circle), so that they can speak in the language of CLimax, LSD ratios and so on, that the developers understand. 

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That's what I also fear, because no matter how many warning they get, some people just can't hold themselves and blend potentially valuable information in personal attacks and insults.

 

It would require at least a moderator to keep a careful eye on the thread and delete immediately any post containing clear or hidden personal content instead of editing it.

Maybe in the end people will get tired to have to write the same things again and again and eventually learn to stay factual about their input on the subject.

 

I guess I'm an utopist, but I don't see how else we could get the needed correction about the FM.

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:o: is this real?

 

Implying an agenda because of just one line like that is maybe a bit strong of a statement. We have no idea what Han really thinks and much less why he thinks what he thinks. People here in the forums drop a line that prove to be suboptimal ex post often enough. Sometimes people deserve a break.

 

Giving the devs the chance to do the 190 again in the flavor of the A5 will be a better test of what they really think is right instead of one sentence that you can project a lot into it.

 

Shouting accusations of that kind only gets this thread locked (for good reason) and certainly gives no inventive to give things another look from the side of the devs.

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Actually the question was directed at the answer that Han gave to Jtd's question and not at that statement he made. But maybe should have made that clearer...

Edited by II/JG17_SchwarzeDreizehn

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I wonder what previous data was based on? 

 

Also some customers explain that could be error in anayzing documents which used developers to change Clmax and cAoA in last update:

 

Developers reconfigured Fw-190 on the document:

post-2090-0-02341300-1470820990_thumb.jp

This purging of the aircraft in a wind tunnel at Chalais Meudon. The critical angle of attack is 15.5 degrees. But the Germans made a mistake. They are not correctly defined correction factor. In repeated trials, they found that the angle of the amendment should not be 1.5 degrees. The amendment should be 0.25 degrees. This report was created by them "Messungen an einer Fw 190 im grossen Windkanal von Chalais Meudon bei Paris", Focke-Wulf Bericht Nr.06006, 1943". Developers obviously this is not taken into account. The critical angle to be 16.75 degrees, rather than 15.5. That is, the plane should be a little more stable in extreme turns.

We have sent a report on this issue. I hope someday they will consider it.

 

 

Hi Kwiatek,

 

When did you sent that report to Han ?

Could you copy/paste it here ?

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It was ViRus that sent the report, to the devs which led ot the FM change. I asked him what exaxtly he sent. And I quote him here "IT WAS JUST THE GRAPH". Which is exaclty the one that you have in your post

Edited by II/JG17_SchwarzeDreizehn

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The more interesting document would be the one in which the measurement mistake was stated. I think it was Vachik who said he sent a report regarding the mistake, but I have never seen the actual evidence.

 

Did anybody sent an actual scan of that document ?

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Did anybody sent an actual scan of that document ?

 

 

It's a good question While I'm not An.Petrovich - I can't do a supposition why it is. But it is - we have wind tunnel test reports for these planes and they confirming that we have correct aerodynamic coeficients for these planes. German tube tests for Fw190 shows 1.17 without airscrew affecting ("Messungen an einer Fw 190 im grossen Windkanal von Chalais Meudon bei Paris", Focke-Wulf Bericht Nr.06006, 1943.) Soviet technical desription of 1941 for Yak1 shows 1.33 without airscrew affecting

 

Even though it would be nice to see the document it does not really matter because NACA have already done elaborate testing on both wing designs. It is pretty much impossible for the YAK to have a higher clmax than the 190. As a result it is impossible for YAK to have done better if it had been tested under the same conditions (in Chalais Meudon). But I guess since the devs go with German data for German planes and Russian data for Russian planes common sense is just thrown over board and some dug up graphs are preferred over a rational analysis and profound testing.

Edited by II/JG17_SchwarzeDreizehn

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Well, sorry for being the glass quarter full guy for once, the good news is Han gave a meaningful answer - not quite what I was aiming for, but he gave the sources.

 

Best we can do now is to obtain and look into these sources, find out about different rigging, different dealing with stabilizers and control surfaces, different aircraft preparations, tunnel wall corrections, wind speed, reynolds numbers, other corrections and so on. I'm pretty sure this could be interesting, however, I have no interest in chasing down the documents. If they are for sale, I'd buy them, but I can't waste days or weeks on some at best academic issue right now.

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Best we can do now is to obtain and look into these sources,

 

Do you have the entire report "Messungen an einer Fw 190 im grossen Windkanal von Chalais Meudon bei Paris", Focke-Wulf Bericht Nr.06006, 1943, if not I will try to get my hands on it and contact you via PM if that´s alright.

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These wind tunnel test was made with too low Reynolds number (too low speed velocity) thats why it shouldnt be taken directly. It should be corrected according to other avaliable data. For comparison DCS Fw190 D9 got estimated clmax at power idle about 1,35-1,38. Also critical angle of attack (external view bar unformation) is about 17 deg

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Do you have the entire report "Messungen an einer Fw 190 im grossen Windkanal von Chalais Meudon bei Paris", Focke-Wulf Bericht Nr.06006, 1943, if not I will try to get my hands on it and contact you via PM if that´s alright.

I don't have it, it's 156 pages and I've seen like 15 of them. I'd love to know more, haven't seen it for sale anywhere.

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University of Braunschweig has it. You can order journal copies or outtakes from subito, which are a company specializing in going to universities and getting outtakes like that. As I said, I will try and get my hands on it.

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These wind tunnel test was made with too low Reynolds number (too low speed velocity) thats why it shouldnt be taken directly. It should be corrected according to other avaliable data. For comparison DCS Fw190 D9 got estimated clmax at power idle about 1,35-1,38. Also critical angle of attack (external view bar unformation) is about 17 deg

If you say so, you are probably true.

 

But again, whilst I only have limited knowledge in aerodynamics, one thing I'm sure is that saying so won't make the devs look again into the Focke FM

 

If we want things to change, a complete report must be sent to Han, and I believe it should at least include :

 

- The brief explanation about the matter, 

 wind tunnel test was made with too low Reynolds number (too low speed velocity) thats why it shouldnt be taken directly. It should be corrected according to other avaliable data. Critical angle should be corrected to 17° 

Or something in that flavour

 

- The chart incorrect :

post-2090-0-02341300-1470820990.jpg

 

- An actual in-game test with pictures/calculations/data or whatever is needed to prove that the Fw in it's current version does behave according to the graph above, and that the critical angle we have is indeed 15.5°. I don't know how to do it, but some people seems to be good at these testings.

 

- Then the famous

Messungen an einer Fw 190 im grossen Windkanal von Chalais Meudon bei Paris", Focke-Wulf Bericht Nr.06006, 1943

Everybody seems to know what's inside, but nobody so far gave us any proof that they actually own or have access to that document, or that a readable pdf version is available.

Then the relevant pages and paragraphs where they talk about the miscalculations and corrections about the 1942 testing should be underlined in the text, or at least listed in some way. But I think the whole document have to be made available to the devs because they surely want to read it in it's context, and not only the few paragraphs that are relevant to the FM issue.

 

EDIT : SchwarzeDreizehn good to know we can find it somewhere, keep us in touch about that  :)

 

- And last the corrections to be made according to the 1943 document, or the calculations that gives you the corrections to do if the document don't say it directly.

 

- Probably also good could be an updated version of the 1942 graph with additional curves or corrected axis that shows how the wings behaves in real life.

 

 

 

Now I repeat my question, does anybody sent such a complete report ?

If no, no wonder to me that the claims about the Fw are ignored, or at least postponed to the release of the A5 in the best case, when they will have time to find and dig through the documentation themselves.

Edited by F/JG300_Gruber
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Doesn't necessarily have to do with the comparison Yak <-> 190, rather 190 <-> La5, but i post it here anyway, since this is the place for current FM discussion. 

Found a comparison about La5 and 190. It's about the La5fn and the A8, however there shouldn't be to many differences in what is discussed.

 

"The La-5FN had a slightly better climb rate and smaller turn radius than the Fw 190A-8. However, the Fw-190A-8 was faster at all altitudes and had significantly better dive performance (1) and a superior roll-rate (2). As a result, Lerche's recommendations for Fw-190 pilots were to attempt to draw the La-5FN to higher altitudes, to escape attacks in a dive followed by a high-speed shallow climb (3), and to avoid prolonged turning engagements." source is from Artem Drabkin

 

(1) the biggest issue i have with the game, actually bugs me more then the wrong Cl max. A3 probably more draggy then A8, shouldn't be much of a difference though. At least, when the A5 comes out, we can do final testing, and compare the dive performance to the La5 - difference should be even bigger then to the La5-FN.

(2) superior roll rate to the La5 FN, which already had a better roll rate then the normal La5. I think everyone already knew that the roll rate of the La5 is off, this excerpt further supports it.

(3) is suicide in the game. -->while this is pure anecdotal evidence, no "hard" numbers, i think the most obvious proof if an FM is wrong, is when manouvers and tactics don't work, which worked in history. I wouldn't mind small(!) inaccuracies in FMs, as long as they don't change the character of the aircraft. But if something, which was a valuable tactic in real life, doesn't work in game, then this Sim is nothing else then fantasy. 

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It is, unfortunately. That's why most of our squadron lost faith and don't want to invest in any alpha sequel. But just wait a bit and Luke Skywalker will arive and telling you everything is perfect and you just have to bring evidence...

 

Same here, and Im not going to buy anything else from them till they fix those fm problems.

Not sure if Jason will be able to do anything about that.

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Thats a bad message. "II./JG77_Con, on 18 Aug 2016 - 14:05, said:

snapback.png

IS there plans too FIX currant F.M . 

 

FW-190 with its poor handling stalls we all know what we are talking about .  

 

BF-110 and its damage model with its glass wing . 

"we all know what we are talking about"

It's only emotions. No any historical technical documentation like flight tests reports? No any strict comparing between sorces and game? So yes, we know "what we're talking about" - we're talking about emotions, not about strict fact-supported claims.

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."

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Problem is that developers take dircetly tunel wind test for Fw 190 A  from Chalais Meudon bei Paris and set 1.17 Clmax and 15.5 cAoA.

 

  They should take care that these tunnel test was made with low Reynolds number with velocity 36 m/s which is below stall speed of Fw 190. So these data cant be used directly for estimated CLmax for Fw 190.  It should be estimated based on other data ( wing profil and similar test for other planes which got similar wing profil).  Clmax afected also critical angle of attack - so if Clmax is too low also critical angle of attack is too low in game.

 

So developers made clearly error estimaed Clmax and critical angle of attack of Fw 190 based only on these wind tunnel data without futher more analyze and calculations. It wasn't really professional approach.

 

For example DCS Fw 190 D-9  ( with the same wing as Fw 190 Anton)  got about 1.35-1.38 Clmax ( without aircreew effect) and about 17 deg Critical Angle of Attack. 

 

So for comparsion BOS A-3  Clmax - 1.17 cAoA - 15.5 deg  vs DCS D-9   Clmax 1.35-1.38  cAoA - ab. 17 deg.

 

Here we have why A-3 in BOS is so craped plane.

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copying this here

 

Are you sure this 1.58 corresponds to the Clmax ? I read Ca max on the document. Is it the same thing in German ?

 

Interesting is that German estimaed Clmax for all Fw 190 series as 1.58 Clmax
 
zn7x2d.jpg

Edited by F/JG300_Gruber

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copying this here

 

Are you sure this 1.58 corresponds to the Clmax ? I read Ca max on the document. Is it the same thing in German ?

Cl max is english for C lift , while Ca max is german for C auftrieb (lift in english) = both meaning the same... coefficent of lift

 

what would interest me in the document are the ca R , ca A and ca St figures mean? is the rest of this document available , possibly with the explanations for those abbrevations?

Edited by Zop

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Problem is that developers take dircetly tunel wind test for Fw 190 A from Chalais Meudon bei Paris and set 1.17 Clmax and 15.5 cAoA.

 

Thanks Kwiatek, I have a document that confirms, that the engineers thought that the cAoA adjustment of 1.5deg was too high, but they refer to later tests to correct the number. I do not have the document that confirms that the actual adjsutment was 0.25deg? If yes would it be possible to PM it to me?

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- The chart incorrect :

post-2090-0-02341300-1470820990.jpg

 

 wait...

 

 

the horizontal graph reads out as degree (aoa i think) and the vertical reads out as ca from 0 up to 1.5.....that would mean it reached cl 1.5 (as curve a  and (looks like d) reach ca 1,5...a with flaps and gear up...while d is gear down and flaps to 38 degree....see right description)

 

top reads out as tests done with airscrew zero thrust...

Edited by Zop

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Cl max is english for C lift , while Ca max is german for C auftrieb (lift in english) = both meaning the same... coefficent of lift

 

what would interest me in the document are the ca R , ca A and ca St figures mean? is the rest of this document available , possibly with the explanations for those abbrevations?

IIRC then according to Matt and JtD "R" stands for "Rollen", "A" for "Abheben" and "St" for "Start".

I think there is something strange with the Charles Meudon polar posted earlier: If you look at the Camax with full flaps it’s only about 1.48. Now the German drag table lists Camax as 1.58 and as Matt has shown earlier this is with 60 degrees of flaps as well so the CM measurements are 0.1 off from the figures listed in the table.

 

This discrepancy may either be due to Reynolds number effects or measurement errors. Anyway, it shows that the Charles Meudon measurements should be taken with a grain of salt.

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what would interest me in the document are the ca R , ca A and ca St figures mean? is the rest of this document available , possibly with the explanations for those abbrevations?

Rollen - taxi, take off roll

Abheben - lift off

Steigen - initial climb after lift off

 

Used for the calculations of take off and landing distances and speeds. Camax in this context is used for calculation of landing speed flaps down, gear down.

This whole table has nothing to do with actual data, these are fact based, rounded, simplified and generalized assumptions used for the calculations.

 

the horizontal graph reads out as degree (aoa i think) and the vertical reads out as ca from 0 up to 1.5.....that would mean it reached cl 1.5 (as curve a and (looks like d) reach ca 1,5...a with flaps and gear up...while d is gear down and flaps to 58 degree....see right description)

d and e reach 1.49, a (and b) reach 1.20, different only at low angles of attack. c reaches 1.26. Edited by JtD

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Rollen - taxi, take off roll

Abheben - lift off

Steigen - initial climb after lift off

 

Used for the calculations of take off and landing distances and speeds. Camax in this context is used for calculation of landing speed flaps down, gear down.

This whole table has nothing to do with actual data, these are fact based, rounded, simplified and generalized assumptions used for the calculations.

 

d and e reach 1.49, a (and b) reach 1.20, different only at low angles of attack. c reaches 1.26.

hmm looks like a a to me....its hard to read... :D

Edited by Zop

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