Author Topic: IL-2: Oleg's explainations about roll rates.  (Read 1706 times)

Offline JG5_Jerry

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IL-2: Oleg's explainations about roll rates.
« Reply #30 on: September 06, 2001, 05:58:00 AM »
Ok  ;) If it counts, I've helped Oleg with some research material for the sim and he's always been very kind and courteous. The fact that he's spent 1 year+ getting ideas and suggestions from the sim community speaks volumes, to me at least. I'm not a groupie by any means, but fair play!

Offline gripen

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IL-2: Oleg's explainations about roll rates.
« Reply #31 on: September 06, 2001, 09:53:00 AM »
Well, 360 roll time of around 3 seconds for the Bf 109G sounds about twice as fast it really was. My best quess for explanation is that their sources used radian values for rolling velocites and they calculated translation to the degrees wrong. If the Bf 109G did at best say 1,4 rad/s then the correct translation is 360/2pi and this results about 80 deg/s but I quess they used 360/pi which results 160 deg/s.

gripen

Offline fscott

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IL-2: Oleg's explainations about roll rates.
« Reply #32 on: September 06, 2001, 10:21:00 AM »
GRIPEN.

In Oleg's latest russian speak, he said the bf109 does not have a faster rollrate than the fw190.

SO I think it has more than likely been toned down a bit to represent a less than superhuman strength pilot.

Offline gripen

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IL-2: Oleg's explainations about roll rates.
« Reply #33 on: September 06, 2001, 05:23:00 PM »
At 250km/h this is not a stick force issue but almost certainly a mistake somewhere. Another possiblity is biased data but to me it seems to be wrong formula for translating radians to degrees.

gripen

Offline Sundog

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IL-2: Oleg's explainations about roll rates.
« Reply #34 on: September 06, 2001, 08:47:00 PM »
Just posting for further clarification. As Funkedup correctly posted, compressiblity begins when the critical Mach number is achieved. What this draws from is the fact that air is 'Compressible'. It compresses into shock waves at very highspeeds. Basically, the critical Mach number is the speed at which shockwaves begin to form on the aircraft. This is the beginning of the transonic region.

Note: The main regions of flight most modern combat aircraft deal with are: (1)Subsonic-The airflow around the flight vehicle is completely, well, subsonic, below the speed of sound. (2) Transonic- The airflow around the aircraft is subsonic in some areas and supersonic in others. The combination of the two generally leads to very high drag, which is why aircraft typically need alot of power to break the sound barrier (compared to subsonic aircraft).(3) Supersonic-The airflow around the aircraft is fully developed supersonic flow.)

Now, most aircraft of the period would begin to 'compress' in a dive because the air flowing over the top of the wing would become supersonic. The result is a rearward shift in the aerodynamic center. One result of this is that the pitching moment generated by the wing may now become too great for the tail to overcome.  (Since the designers didn't know much about this phenomena or how to size the horizontal stabs/elevators to overcome this). Now add in that the shockwaves will effect the airflow, which can effect flight control effectiveness, create wake turbulence that structurally damages the aircraft, and based on the 'design' (Configuration, airfoils used, incidence angles, etc) can have all sorts of detrimental effects on the 'tail' control surfaces.

As such, you can see why when aircraft entered compressibility, it could be very difficult to recover from, sinc egenerally the aircraft would want to increase its dive angle as a result of these effects, therefore speeding up even more, which just exacerbated the problem.

I hope I didn't get in too deep for some of you. I was just trying to offer a somewhat simplified and somewhat accurate explanation for what the effect of 'compressibility' is and does to aircraft.

Offline Boroda

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IL-2: Oleg's explainations about roll rates.
« Reply #35 on: September 07, 2001, 06:57:00 AM »
Miko, what did you mean by "communist terminology"?

The only thing I can guess is that it was the word "буржуй" ("bourzhui"), meaning the foreign flightsim community.

Miko, in modern Russian slang "bourzhui" means "a foreigner from the capitalist country". For example: Poles or Bulgarians are not "bourzhuis".

Or should I call the foreign community in a ceremonial Chineese way, like "наши драгоценные преждерожденные единочаятели с запада"?  ;)  (www.orduss.ru - Miko, they have put Holm van Zaitchik's "Case of an avid barbarian" online, definetly worth reading  :))

The general sarcastic tone of my letters there is caused by my disappointment and inability to imagine any reason for this contradictions. As I already said - I finaly admitted that I am unable to understand Oleg's explanations, and stopped worrying.

Why I call myself "commissar": back in 1997, when we formed 25th IAP, the first Russian-speaking squad in WB, we have chosen "ranks" for everyone of 10 members. I became a "commissar" because I talk more then fly ("Вам хорошо, товарищ замполит: рот закрыли - рабочее место убрано"  :)). "Hen is not a bird, commissar is not a pilot". It was a joke. Later it resulted in preparing glintwein at the meetings and deciding what should we drink now  ;) (замполлитр, или поллитрук ;)  :)

Offline miko2d

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IL-2: Oleg's explainations about roll rates.
« Reply #36 on: September 07, 2001, 01:16:00 PM »
Quote
Originally posted by Boroda:
[QB][/QB]

 Boroda, to put things into perspective, I did not claim in my original post that Oleg was a bad person or that people posting on the russian forun were bad or anti-west communists. Just that a westerner reading that could form a mistaken negative impression - because of culture differences, etc.
 There certainly seem a lot of culture differences for me - those accumulated over 11 years I've lived in US.
 I certainly believe you that there is no offence ment. I might doubt the use of divisive terminology in any case because nnobody ever prospered brom division. If the term is innocent for russians, there is no problem for them in using it where weterners have no chance to see it. Quite like the american term "Jap" which is just an innocent contraction but apparently offends japanese.

 To me the word "bourzhui" meant "evil class enemies scheduled for eventual extermination", about the same negative loading as "fascists". I would use term "westerners" myself.

 On this topic the further discussion is kind of pointless because we are not at odds but just exploring different meanings of the word and it's perception by different cultures.
 If I see you stop using that word "bourzhui" in the future, I would be glad. If not, I will not be upset in the least because I know it does not mean what I first suspected...  :)

 On a side note, it is curious how ignorant many russians still are about workings of western society - the P51 conspiracy that would not let any games to be published if P51 is not the best plane - as an example.  :)

 A word "comissar" for me, thou obviously not for many others is associated with the worst that the communism has ever prodiced. I base my prejudices on books and statements of eyewitnecces, including some surviving relatives.
 Army commissars were an independent chain of command separate from line officers who were representatives of the party. Their job was to watch for signs of "treason", moral and political "immaturity" among officers and soldiers.
 Despite image build in movies of comissars raising soldiers in the decisive assault and leading from the front, their real job was spying, forcing people to become informers, collecting damaging information for real or imagined fault, terrorising their own people.
 In short, the commissar was not a man who lead soviet soldiers but who shot them in the back of the head.
 Unlike regular officers, who could do their job well by executing orders of superiors (or at least losing enough of their soldiers to make an impression that they did all they could) and reporting enourmous casualties caused to the enemy, comissars had to show uncovered "traitors" and "enamies of the people" with the easiest outcome for the involved being demotion and penal batallions where life expectancy was counted in days.
 If some comissar went soft and found fewer "e.o.p.s" then the next one, he would be first on the list of his superior comissar, but of course soft persons never went into business of exterminating their own people.

 I hope I do not offend you and I am interested in you take on that. Maybe in a different thread because we are getting way far from the roll rates here...  ;)

 Regards,
 miko

Offline Badboy

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IL-2: Oleg's explainations about roll rates.
« Reply #37 on: September 07, 2001, 08:37:00 PM »
Quote
Originally posted by fscott:
GRIPEN.

In Oleg's latest russian speak, he said the bf109 does not have a faster rollrate than the fw190.

SO I think it has more than likely been toned down a bit to represent a less than superhuman strength pilot.

I’m curious about this. If it is true, particularly after the manner in which Oleg defended this point with reference to Russian flight test documents, it raises a serious credibility issue. Do you have a quote or a link?

Badboy
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Offline wells

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IL-2: Oleg's explainations about roll rates.
« Reply #38 on: September 07, 2001, 08:55:00 PM »
Badboy,

From here,
 http://www.simhq.com/simhq3/sims/boards/bbs/Forum35/HTML/001213-4.html

Oleg said,

 
Quote
1. IF I'm wrong - I always will try to correct myself and say to all that I was wrong. In Demo we get P-39N-1 roll rate 2,2 sec....(that is exact digit, which show program itself in our special tools) Ok. It differs from what I twice checked for that weekend. The best roll rate for that plane was 3,4 sec. Better than P-63A ! And I know why.... So in final we'll get something like that digit.

Offline Badboy

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IL-2: Oleg's explainations about roll rates.
« Reply #39 on: September 07, 2001, 09:45:00 PM »
wells,

Yep I saw that post regarding the P-39 but I haven't seen Oleg retract his statement regarding the roll rate of the 109 v 190 as suggested in this post by fscot.

 
Quote
Originally posted by fscott:

In Oleg's latest russian speak, he said the bf109 does not have a faster rollrate than the fw190.

Is there a quote or a link to support that?

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Offline fscott

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IL-2: Oleg's explainations about roll rates.
« Reply #40 on: September 08, 2001, 12:36:00 AM »
Badboy, you need to translate the link in the first post of this thread.  

He is referring to early model Fw190's such as a3, of which I totally agree.  Later model 190's had too much weight on wings to roll like the a3/4